Having built a suitcase type electrical system for my little boat which is removable I kind of understood this video as I went through the same process myself. I do have an automatic cut out if for any reason water gets into the box. I only have one battery as my boat has an outboard. I have a solar charging system and the ability to keep my radio GPS chart plotter and phone all charged. Plus I have a marine ordinary radio installed to keep me company along with a mini antenna. Love this video as it was very interesting and very educational. One thing that does impress me is how bullet proof and neat your work is as you take pride in what you do, it is very hard to find people like you so well done.
It would be great (if you could in another video) to include a diagram of your electrical installations; it would make it really easy to understand where things fit into the system (in particular things like fuses, bus bars, wiring..). Keep these great and informative videos coming!
It's quite simple, due to the fact that this uses a bidirectional dc to dc converter (ie much simpler than some odd configurations recommended elsewhere). Starting with a conventional small boat wiring configuration you: 1. replace the existing lead acid house bank with lithium; 2. any smart charger or solar controller remains connected to that lithium house bank (provided they have a lithium setting, otherwise replace); 3. the alternator remains connected to the start battery (which remains lead acid chemistry) - you may wish to install a larger capacity alternator but this is not essential; 4. the only real change is to remove any automatic battery combiner and 'bridge' the two banks with the (reverseable) DC to DC convertor. 5. You can add a battery condition monitor to the house bank, but that is optional (requires a shunt on the negative return, to read the current and other wiring, as instructed by the monitor instructions). Other than that, it is mostly tidying up (adding fuses where none were fitted, installing busbars to manage wiring better etc). Only two questions I had were (i) should the windlass remain connected to the lithium house bank (presuming it was originally wired that way) - that may depend on which lithium battery you buy, (ii) the wisdom of fitting a manual combiner (but provided you understand when and how to use it, that's not controversial).
Caution: this installation lacks any discussion of fuse sizing and a supporting schematic. Calculating the correct power fuse for a engine starter feed can be base lined using an amp clamp while cranking with a fully charged battery. Use ohms law to calculate current increases when battery voltage drops. Fuse size consideration are also required when house and engine batteries are combined and further consideration warranted; if one is discharged or the chemistry between banks differs. No disrespect to the creator, his work is top notch.
Thanks and agree, I try not to get too deep and technical in the vids and always have the note in the description that if you are unsure then consult a professional. I have tested the pull of a starter of an engine similar to the one on this video and it was about 75a from memory so I normally use a 150A fuse which is still well below the rating for the cable. Definitely an advocate for fusing batteries correctly as I have see the aftermath of a shorted battery cable with no fuse and the results were scary.
You answered my key question, in that you have found a DC to DC convertor that can act in both directions (ie shore power + solar connected to the house bank and alternator connected to the start battery can charge both banks). That is a massive improvement on some very odd configurations, recommended on some YT channels. Definitely the way to go.
Great video. I’m doing very similar on my refit. I like the sterling B2B unit you used better than the ones i bought. Now buying Sterling and returning mine. Thanks for the Sterling discount. Beer money on the way.
Great content! You are a talented shipwright. A word on the lithium chargers. There is a battery charger on the market that can charge different chemistries, it’s Genius! Wish my victron Dc/Dc charger did reverse feed!
Interesting, which one. The only multi chemistry batt charger I have seen needs an extra “magic box” (that I suspect is a dc to dc charger) connected to one of the outputs of the first charger to alter the charging profile. Sterling manage it this way. Which one have you seen I asked victron a short while ago and they had noting that would do multi-chemistry
Which one? Nigel Calder, in a bideo the other day, said no smart charger on the market today can feed two different chemistries. (ie even if you have a smart charger that can feed two or three different banks, bank number two and three follow the instructions of bank one.
I'm so glad to have found your channel. Your content is great and easy to follow. Based on this video, I may actually try to install lithium myself on my 2006 Bavaria.
Long time watcher here from Australia. Love your work. Had to chuckle at the sped up parts as I am almost seeing light at the end of the tunnel on my TOTAL rewiring of my 26ft FRP yacht from 1983. The wiring was, well, a fire waiting to happen. Reason for my post was to say to people, I rewired, fused, labelled, replaced every wire including a new gauge panel and engine wiring harness (Yanmar 1gm10). I've over engineered and modernised the electrical systems on my boat & I've done everything to exceed all standards. You can't be too safe with wiring on a boat lol. Point of story: OMG out of all my projects on my boat, the most money spent & the most time spent, has been electrical. It's a deep rabbit hole haha, much, much deeper than I expected. I started with replacing the gauge panel and 6 months later lol, the entire boat is almost done.. Edit: I am in AUSTRALIA, so take that into consideration when I say expensive. Everything we buy is more expensive than what you'd get in the USA or Europe FWIW.
Yep, it’s definitely a Rabbit hole you can dissapear down and spend a lot of money on if you wish but I like to keep things relatively simple and on my boats would rather spend the money on sails and things than make the boat work at sea rather than the very latest electric or electronics stuff. But each to their own. The critical thing is that the systems are safe and fit for purpose, the old wiring on this boat was ready for the recycling bin!
@@RefitandSail had a good chuckle re: recycling bin! I can imagine.. There are so many boats around the world with 'she'll be right' and 'that should work' wiring, waiting waiting to catch on fire. I can't believe I sailed mine last year with the state of the wiring. Yikes 😬😬😬🤣
Like you, i rewired my boat (a 1975 CAL34), but while still cruising. Step 1 - remove all redundant wiring (probably 30% of the total). Step 2 - rewire all AC circuits, one by one; Step 3 - rewire all high current DC circuits, again, one by one etc etc, until I got to the instrument wiring. Oddly enough, replacing AC and DC panels was my final step. Like you, it took me about 6 months but I was helped by my wife, who has very small hands, and was therefore able to do get to all the difficult places better than me. Some recommend pulling it all out and starting from fresh but that wasn't an option for us as we were still living on the boat.
By the way, the best deal anywhere is to buy from the UK for delivery to the US.. No UK VAT; no US State taxes; no customs duty (unless you buy something big) and reasonable shipping costs. I appreciate that doesn't work for many people, however ;).
@@stephenburnage7687 I don't think ripping it all out is a good idea for one important reason (not 'so' important on my 26ft boat) is that you can chase the wires already in place! I've kept all my wiring in place for now, especially the mast wiring, even though it's not used. Come time to run wires that way, it will be some much easier :) you're right about the scope of the project though : to do it once & do it right it's a huge job haha... I thought replacement of all the deck hardware was hard but in hindsight was much easier & quicker than the wiring
After a small fire, i decided to take a good look at my 1970's wiring. Found a full 30% was energized, unfused but not connected anywhere. Needless to say it is not like that now.
Just an FYI, the marine 12v wires are now yellow and red, with yellow being the negative. Boats also have AC wires, whereas the blacks are hot and not negative.
Interestingly, that circuit that runs start battery - starter motor - alternator is the one circuit that ABYC does not require to be fused (on the basis that the current draw is so large). Like your parents, however, it is the one circuit on my boat where the insulation broke down and began to short and smolder (which i caught before it developed into a full fire). Nigel Calder now recommends addiing a fuse (but a large one, such as 300 Amps). Others recommend a smaller fuse but in parallel to an on-off switch (so that you can isolate a blown fuse if in need of starting the engine). Others talk about slow acting fuses. So far, all i have done is add an isolator (so the circuit is only energized when the engine is running or starting). Would be interested to learn how you approached this.
I fuse but well above the likely amperage of the starter, not had one blow yet from use. I always supply spare fuses to the owner so if it did blow the fuse can be swapped out quickly.
Boats in the uk generally don’t have lightening protection systems as it’s not as common as it is in the US or other parts of the world. Worth looking at though!
Question: When the B2B senses the full charge from the LifePo4 and starts charging the AGM with the extra power from 240v or solar, does it change the charging profile to AGM and not LifePo4?
Brilliant video, I want to do exactly the same on my moody 36. I have 300 amps of lead acid. I want to add a 320 lithium. Could you please list all the parts used apart from the battery?
Great video - very inspiring - thanks couple of questions: How about a bilge pump connected directly to the house bank? If you had a multi battery isolator would you ditch that and go for the dc-dc solution shown here?
Auto bilge pump is the ONLY thing attached direct to the house battery (well to the fused side of it). And yes to the second question - if I understand your system but hard to say without seeing it really
Out of interest, did you wire the windlass to the house or start bank? Most lithium battery manufacturers recommend against high current loads (not because of the battery itself - but because the BMS is set to trip out under high loads). The specs for this battery, however, state it will accept 100A continuous. What do you normally do?
There is no windlass on this boat so not really a consideration. If fitting one on this particular boat I would wire it into the house bank as the engine starter bank has a low AH rating because it’s designed to be a starter battery and provide high cca’s for its size and weight. A windlass on this size of boat would be well under 100a
George. Ive got a Beta 14hp and looking to install a new starter battery. I think you have previously metioned that Motorcyle starter batteries can be used, possibly AGM. I've got the Sterling DC to DC charger ready to go after the recommendation in this video. For my Beta 14, what Ah capacity starter AGM bat do you think I should consider getting? Is an 19Ah AGM too small? The house batteries are 2x 100Ah LiFEPO4.
Starter batts are rated with CCA (cold cranking amps) not AH as they have to deliver a high current for a short period of time. So you need to check the spec from beta. Beta 14 is a small engine so only a small starter batt is needed to spin it over
Beautiful work and very precious for me. Thanks you very much. I have the same work to do on my Contessa. All the installation is from 1976 without any security (fusibles in french) I will make exactelly the same because it is simple for me and for my boat. I don't want complicated things. I like make electricity, because, like you, it is clean, précis. I have learn on my precedent boat a Marieholm 26 for the first time. Do you explain in an other video how change the electrical cables of the differents cabin lights. I tried to pull them, it is impossible. And they are original. 1976 rigid every where. I suppose there must be a lot of connections under the linings and I dont want dismantle all this and I don't like when I cannot see. I thought I'd run new cables under the fittings and reduce the number of lights.... I can't take advantage of your discouts on equipment because there are too many customs taxes for France, it's a shame. I offer you some bears with pleasure for all your work.
Hi and thanks for the message. In my experience it is almost impossible to replace the original cables that are in the headlining so I generally have to reuse them and so far it has been ok. To pull new cables for lighting into the gap between headlining and deck is impossible. For things like the mast lights you can run new cables to the base of the mast and then replace the mast cables so that they exit at the bottom of the mast. I hope this helps. Good luck.
When I rewired my 1970's boat I found several cable routes that could not be replicated today. Had to start with brand new locations for some loads depending on where you could run the new cables.
Remembering that the fuse is there to protect the wiring and knowing what the capacity of the wiring is you set the fuse below that. Starter motor prob pulls 80a maybe 100 but no more on a small engine like this. 150-200a fuse is fine for this application.
Another question for you George: I’ve noticed that in several of your videos, you’ve fitted these relatively small AGM starter batteries, and this video shows the model you seem to like - the Odyssey Extreme ODS-AGM40E. Looking up the specs, I see these have adequate cold cranking amps, but their rated capacity is only 45 Ah. I just completed a repower on my boat with Beta 20, and noticed they call for using a starter battery of minimum 70Ah. Do you have any concerns about this, particularly in maintaining the engine warranty coverage on your Beta repowers? (I known an under-capacity battery shouldn’t affect an engine, but sometimes companies may look for ways to protect themselves from warranty claims.) Beyond that, another wonderful video. Your earlier videos were essential to building my own confidence to tackle my first repower single-handed. Enjoy another pint on me.
If you look at the specs for various sizes of beta they recommend the same size battery for smaller and larger engines so for the smaller size engines like a 20/25 the smaller battery will be totally fine. The reason beta give an amp-hour rating is that many boat owners use batteries that don’t have a cca rating because the are cheap flooded lead acid batts, so beta take the view that the average 70ah FLA will be capable of providing the appropriate cca’s. In reality it’s much better to state what cca’s are needed as amp hour capacity does not actually indicate how suitable it is for the job of starting at high amperage. Hope that makes sense. I can’t believe for a second that beta would deny a warranty claim on those grounds given that I could specially choose a 70ah deep cycle battery that has low cca’s because it is designed for low draw and deep cycling. Beta are a pretty sensible company (I have spoken with the MD a few times). No one has reported any issues on the boats where I have installed these specially designed high cca stater batteries.
Makes all the sense in the world, George! And just to second your sentiment, the folks at Beta Marine are indeed wonderful, and eminently reasonable. I’ve only dealt with their American outpost, Beta Marine USA, but the staff there provided invaluable advice for my repower, both during the purchase process and during the installation. I think I’ve just gotten burned (or nearly burned) enough with warranty issues in the automotive world that I’ve become a bit paranoid!
This is something I had been thinking of doing on my boat. I've decided not to because it isn't worth the cost of the lithium battery. But when I was looking into it, I did wonder if the DC2DC charger would reverse charge. If not, you could put all your solar onto the starter battery, but would the charger push power into the house battery when the solar was charging the starter? Maybe the solar charger will stop when the starter is full.
I've just installed a Victron setup on the starter battery side of my engine. It's a Yanmar 1gm10 1983. Starter battery is a 72wh 350CCA Lifepo4. Because it's an old alternator I've wired it as follows: alternator to Victron Argofet (this provides a buffer between the alternator and the starter battery if the alternator decides to shut off its output). Then, the output from the Argofet goes to the Victron Orion-Tr Smart Isolated DC-DC charger (this provides the correct charging profile for the Lifepo4 starter battery). Maybe that helps you? It's an unconventional setup lol but it works. For the house battery bank I will be using solar power & a Victron MPPT. Regarding grounding, there is ONE ground wire to the engine block that runs to the negative (500A) busbar connected to the negative terminal of the starter battery. EVERYTHING start related is grounded to this busbar: accessories, gauge panel, DC-DC charger etc etc. Unfortunately you do need a ground to engine for the temperature sender and oil pressure sender, as they are grounded through the engine..
Also wanted to say, lifepo4 battery prices are coming down, not too expensive now. Well, here in Australia I recently bought 2x 120Ah LiFePO4 batteries for approx $400AUD. Only buy Lifepo4 for your boat, it's the safest option for marine environments. Don't buy any other type of lithium
Lithium batteries have continued to drop in price so may be worth investigating again. The original Sterling B2B I fitted to my boat a few years ago didn’t have the reverse charging function that the new ones do so I’m thinking of swapping it. You could do as you say and put your renewables into the starter battery and charge the main/domestic bank from the B2B but that would be an unusual way to do it. In theory the only thing your starter bat should be there for is starting the engine so should need little more than an occasional maintenance charge which is what the reverse charge feature is ideal for.
@@RefitandSail there are some great bargains out there for lithium, prices are steadily falling. Not sure about UK but they're probably cheaper than Australian prices lol. My setup is for the alternator to charge the starter when it's running, as it only needs a little top up now and then but 2x solar panels for the house battery bank. Victron Smart Shunt on the start battery side + the DC to DC charger let's me see the voltage of the battery at all times. My ancient starter battery weighs more than my 120Ah LiFePO4 lol. I love lithium tech, just amazes me. Even my starter battery, it fits in the palm of my hand, just amazing. And the engine starts better than ever with it.
Did the Contessa have an old fashioned automatic combiner (which combined house & start when a charging voltage was detected) and, if so did you remove it? (It's function having been effectively replaced by the DC to DC convertor).
No, it did not even have that, as per the video it had a 1,2,both,off switch (now replaced) so the skipper had to manually select what bettery was in use/being charged which is fine if the skipper knows how the systems work but a lot of owners I work with just want a simple on/off and the charging of all banks to be automated.
Hard to comment really as every owner/boat has a different use case and budget. Running the boats main engine just to charge is inefficient and not great for the engine but with a chunky alternator and decent regulator the charging can be achieved relatively quickly. Some boats done have space for or the budget for a generator. Personally I would rather have renewables such as solar and wind chargers and my boat is completely self sufficient on power outside the winter months and have tons of energy to spare when in the Caribbean. I bought a small generator as a backup but literally never used it!
I am slowly increasing my solar capacity, with the goal of never having to run my generator at anchor. Up to 400W of solar but still not at break even yet. Part of the challenge for me is the tropics is difficult as days are shorter and ambient temps (ie fridge load) higher. 400W of solar would probably be more than adequate to break even in most cruising areas.
Hi, First off love your channel and watched loads of your videos. Just a quick question on this one, is there any grounding needed for the lithium battery? Also if there was an inverter fitted how/where would you ground the case?
The boat doesn’t have a grounding plate but does have a hull anode attached to the engine and by extension is connected to the battery neg. If an inverter was fitted the neg/hull anode would be the ground. Pleased you like the vids 😊
@@RefitandSail Thank you for the reply and the extra info on an inverter. I'll have to re watch the video as I didn't see how the negative terminal of the lithium battery was connected to the engine. 👍
@@ontheriver6518I didn’t show every last detail or the video will be hours long but there the engine neg/ground is connected to the 4-stud neg bus-bar.
You mentioned that you included a manual selector (so that, in an emergency, you can combine start + house banks) but then you said you would quickly switch it back to position one (banks parallel) if the engine was running. Surely not? If you have a running engine, when you change switch position, you momentarily go through zero load, surging the alternator voltage and potentially blowing the alternator regulator diodes? Or am i missing something?
This switch does not go though “off” between “on” and “combine” so the alternator is never discounted while charging so not a problem. But you are correct in that you could never switch off an engine battery switch as it will likely blow the diodes in the alternator (depending on how it’s connected).
If I wanted to use a DC/DC charger like a Victron Orion-Tr Smart, which I believe does not have the reverse capability, could I just install a single shore power charger on the engine battery?
Sure, you could do that, the only issue may be that as the voltage rises on the engine batt the dc to dc charger may then tick in and start trying to charge the domestic bank so you may need to disable the dc to dc if you are charging from 240. Hope that makes sense.
@@RefitandSail Isn't that what I would want it do? In order to keep the LiFePO4 topped off. Or should I just get a 2 bank charger, like the NOCO Genius GEN5X2? What are your thoughts on the Orion XS? This boat spends most of it's time on the dock, running the engine just to get in and out of the marina for day sailing. (Actually 120 on this side of the pond)
@@schwarz6337ah, sorry I miss understood. It’s more common to have the shore power battery charger on the domestic bank because that’s the one that gets worked hard and pulled down by the systems on the boat. There should be noting on the engine start battery apart from the engine and that recharges once the engine is running. You could do it the way you suggest but it would be slightly out of the ordinary (but it would work. I would personally stick with the more normal arrangement and charge the domestic bank direct off the 110.
Is there a reason you are using fuses for the batteries instead of installing a separate Breaker next to them? Seems that if a fuse blows and the short is repaired one might not have a spare fuse (years down the road)?
The use of fuses rather than high amperage breakers seems to be pretty std practice, that’s not to say that we should never consider other options. I always supply a spare fuse when I do an install like this so if that is used then it’s up to the owner to ensure the spare is replaced and kept onboard.
@@RefitandSail There are exceptions, but my understanding is that breakers do not generally have a fault current rating to guarantee contact separation on a full short. They also have a tendency to become progressively more sensitive with attendant nuisance tripping. As mentioned above, main battery fuses should also be selected for a type that has sufficient fault current rating.
Why have you run the shunt to the negative of the starter battery and not the Domestic battery? Are both the negatives of the starter and domestic connected?
The shunt is reading current for the domestic batteries only, the neg for the engine battery is connected to the common neg bus bar in the battery compartment so the shunt does not register any current to and from the engine batt, only the domestic bank. However there are small voltage sensing wires to both batteries for the battery monitor to record the voltages of both batts. Hope this answers your question
Yes, good question, there are AGM batts designed for deep cycle and there are AGM batts designed for starting engines and there are hybrid options. As this is a dedicated starter batt I have chosen a battery that is specifically designed for that application, it has very thin but large surface area plates so it is able to give very high CCA for its physical size. Also these are not large boats with large lockers for storing batts so a compact battery like this is a bonus and these particular batteries have proven themselves in terms of long life and performance in use. Nothing wrong with having a physically larger agm as long as it can deliver the cca’s the engine needs but no benefit really and it’s likely heavier and no point in having a larger AH capacity on a stater batt.
Just a quick question George . Did you replace the Vetus battery selector for any particular reason , or was it purely an age thing ? didn't fit with the installation ? .
Yes because it would only allow the boat to run off one battery or the other and the starter battery is inappropriate for domestic use and vice-versa. Switching between batteries on every engine start is a PITA and I want to fit a simple and safe system where domestic loads can only come from the domestic battery and engine batt is saved from accidental use. This is a bit more idiot-proof (the owner is not an idiot, he’s a doc, bit simple systems are always best).
@@RefitandSail Thank you George . I use a Vetus switch myself , but i use it with two battery banks . I just wondered if maybe you knew , or had come across a problem i didn't know about !
Lifepo4 batteries are capable of very high currents in a direct short. Are you sure that that fuse is sufficient? Nigel Calder recently did a video suggesting all lifepo4 batteries should be protected with a fuse with a 20,000 AIC. Class T or HH fuses have such a rating. The American ABYC standard says use class T( class T is an American standard fuse) in Europe we have HH fuses. I built my own lithium batteries. I used HH00 fuses. Also, I am one of the few people who has seen inside a Sterling lithium battery. In my opinion, the build quality of those batteries is very poor. Using builders foam to secure the cells is not acceptable. They look like a very poor home built battery inside. Their use of Daly BMS is also poor. Far better to look at Fogstar batteries. Quality cells and good BMS from a UK supplier. Sterling just buy in cheap Chinese batteries and stick their label on from what I can see.
I see that the new lithum house battery has 150ah of nameplate capacity. Have you figured out what % of that nameplate capacity is routinely accessible, long term?
Sorry! but my brain is hurting? Mechanical I understand ,Engines/ gearboxes/winches etc.I never thought years ago that electronics would become such a big part of our lives so became mechanical rather than electronic. but I have a gps chart plotter but my grandson has to do any programing etc etc I do enjoy your videos but this is still beyond me lol🥸🥸🥸
Yeah, I get that, I have friends that just don’t “do” electrics. I’m much the same way as I just done “do” or find it hard to learn languages. Are brains are all wired differently (no pun intended!). I try to make the explanations as simple as I can as I like simple but will be back to boat fixing in future videos or maybe even some actual sailing!!
Safe lithium batteries on a boat. No thanks. I seen too many lithium battery fires. A video on putting out lithium battery fires on a boat should be made.
Having built a suitcase type electrical system for my little boat which is removable I kind of understood this video as I went through the same process myself. I do have an automatic cut out if for any reason water gets into the box. I only have one battery as my boat has an outboard. I have a solar charging system and the ability to keep my radio GPS chart plotter and phone all charged. Plus I have a marine ordinary radio installed to keep me company along with a mini antenna. Love this video as it was very interesting and very educational. One thing that does impress me is how bullet proof and neat your work is as you take pride in what you do, it is very hard to find people like you so well done.
Very pedagogical. Thank you!
Thanks for the discount codes, 150AH ordered and a 15A BB charger sweet 😊
It would be great (if you could in another video) to include a diagram of your electrical installations; it would make it really easy to understand where things fit into the system (in particular things like fuses, bus bars, wiring..).
Keep these great and informative videos coming!
Understand, thanks for the comment. You are not the first to ask this but I have yet to do it
It's quite simple, due to the fact that this uses a bidirectional dc to dc converter (ie much simpler than some odd configurations recommended elsewhere). Starting with a conventional small boat wiring configuration you: 1. replace the existing lead acid house bank with lithium; 2. any smart charger or solar controller remains connected to that lithium house bank (provided they have a lithium setting, otherwise replace); 3. the alternator remains connected to the start battery (which remains lead acid chemistry) - you may wish to install a larger capacity alternator but this is not essential; 4. the only real change is to remove any automatic battery combiner and 'bridge' the two banks with the (reverseable) DC to DC convertor. 5. You can add a battery condition monitor to the house bank, but that is optional (requires a shunt on the negative return, to read the current and other wiring, as instructed by the monitor instructions). Other than that, it is mostly tidying up (adding fuses where none were fitted, installing busbars to manage wiring better etc). Only two questions I had were (i) should the windlass remain connected to the lithium house bank (presuming it was originally wired that way) - that may depend on which lithium battery you buy, (ii) the wisdom of fitting a manual combiner (but provided you understand when and how to use it, that's not controversial).
Thank goodness for Refit and Sail! You have pretty much laid out a template for a new electrical installation in my Sadler. 🍺
Cool, pleased it was helpfull
Me too
This is the first video about electrics i watched after years of Boat videos!
Thanks
Caution: this installation lacks any discussion of fuse sizing and a supporting schematic. Calculating the correct power fuse for a engine starter feed can be base lined using an amp clamp while cranking with a fully charged battery. Use ohms law to calculate current increases when battery voltage drops. Fuse size consideration are also required when house and engine batteries are combined and further consideration warranted; if one is discharged or the chemistry between banks differs.
No disrespect to the creator, his work is top notch.
Thanks and agree, I try not to get too deep and technical in the vids and always have the note in the description that if you are unsure then consult a professional. I have tested the pull of a starter of an engine similar to the one on this video and it was about 75a from memory so I normally use a 150A fuse which is still well below the rating for the cable. Definitely an advocate for fusing batteries correctly as I have see the aftermath of a shorted battery cable with no fuse and the results were scary.
@@RefitandSail Excellent followup explication, you have gained a subscriber.
You answered my key question, in that you have found a DC to DC convertor that can act in both directions (ie shore power + solar connected to the house bank and alternator connected to the start battery can charge both banks). That is a massive improvement on some very odd configurations, recommended on some YT channels. Definitely the way to go.
Great video. I’m doing very similar on my refit. I like the sterling B2B unit you used better than the ones i bought. Now buying Sterling and returning mine. Thanks for the Sterling discount. Beer money on the way.
Thanks. I really like Sterling stuff.
Great content! You are a talented shipwright. A word on the lithium chargers. There is a battery charger on the market that can charge different chemistries, it’s Genius! Wish my victron Dc/Dc charger did reverse feed!
Interesting, which one. The only multi chemistry batt charger I have seen needs an extra “magic box” (that I suspect is a dc to dc charger) connected to one of the outputs of the first charger to alter the charging profile. Sterling manage it this way. Which one have you seen I asked victron a short while ago and they had noting that would do multi-chemistry
Which one? Nigel Calder, in a bideo the other day, said no smart charger on the market today can feed two different chemistries. (ie even if you have a smart charger that can feed two or three different banks, bank number two and three follow the instructions of bank one.
I'm so glad to have found your channel. Your content is great and easy to follow. Based on this video, I may actually try to install lithium myself on my 2006 Bavaria.
Cheers George finally I’m beginning to understand it. 🎉
Great video. Clear instructions. Quality products. Just bought the same battery and DC-DC based on this video. Great work!
Cool, hope you were able to benefit from the discount code.
@@RefitandSail oh yes. refitandsail10 and refitandsail20 worked a treat.
@@MattWilkinsUK fab, good to know!
Long time watcher here from Australia. Love your work. Had to chuckle at the sped up parts as I am almost seeing light at the end of the tunnel on my TOTAL rewiring of my 26ft FRP yacht from 1983. The wiring was, well, a fire waiting to happen. Reason for my post was to say to people, I rewired, fused, labelled, replaced every wire including a new gauge panel and engine wiring harness (Yanmar 1gm10). I've over engineered and modernised the electrical systems on my boat & I've done everything to exceed all standards. You can't be too safe with wiring on a boat lol.
Point of story: OMG out of all my projects on my boat, the most money spent & the most time spent, has been electrical. It's a deep rabbit hole haha, much, much deeper than I expected. I started with replacing the gauge panel and 6 months later lol, the entire boat is almost done.. Edit: I am in AUSTRALIA, so take that into consideration when I say expensive. Everything we buy is more expensive than what you'd get in the USA or Europe FWIW.
Yep, it’s definitely a Rabbit hole you can dissapear down and spend a lot of money on if you wish but I like to keep things relatively simple and on my boats would rather spend the money on sails and things than make the boat work at sea rather than the very latest electric or electronics stuff. But each to their own. The critical thing is that the systems are safe and fit for purpose, the old wiring on this boat was ready for the recycling bin!
@@RefitandSail had a good chuckle re: recycling bin! I can imagine.. There are so many boats around the world with 'she'll be right' and 'that should work' wiring, waiting waiting to catch on fire. I can't believe I sailed mine last year with the state of the wiring. Yikes 😬😬😬🤣
Like you, i rewired my boat (a 1975 CAL34), but while still cruising. Step 1 - remove all redundant wiring (probably 30% of the total). Step 2 - rewire all AC circuits, one by one; Step 3 - rewire all high current DC circuits, again, one by one etc etc, until I got to the instrument wiring. Oddly enough, replacing AC and DC panels was my final step. Like you, it took me about 6 months but I was helped by my wife, who has very small hands, and was therefore able to do get to all the difficult places better than me. Some recommend pulling it all out and starting from fresh but that wasn't an option for us as we were still living on the boat.
By the way, the best deal anywhere is to buy from the UK for delivery to the US.. No UK VAT; no US State taxes; no customs duty (unless you buy something big) and reasonable shipping costs. I appreciate that doesn't work for many people, however ;).
@@stephenburnage7687 I don't think ripping it all out is a good idea for one important reason (not 'so' important on my 26ft boat) is that you can chase the wires already in place! I've kept all my wiring in place for now, especially the mast wiring, even though it's not used. Come time to run wires that way, it will be some much easier :) you're right about the scope of the project though : to do it once & do it right it's a huge job haha... I thought replacement of all the deck hardware was hard but in hindsight was much easier & quicker than the wiring
After a small fire, i decided to take a good look at my 1970's wiring. Found a full 30% was energized, unfused but not connected anywhere. Needless to say it is not like that now.
Neat professional wiring! Well done.
Just an FYI, the marine 12v wires are now yellow and red, with yellow being the negative. Boats also have AC wires, whereas the blacks are hot and not negative.
Great video. Thanks for sharing. Cheers. Jim
Thanks for watching!
Great install. Motivating me to go tackle the rat’s nest in my ‘83 Hunter.
Great video, wish you were out in west Vancouver. You’d be booked solid 365 days a year
You have Pacific Yacht Systems in your area.
Interestingly, that circuit that runs start battery - starter motor - alternator is the one circuit that ABYC does not require to be fused (on the basis that the current draw is so large). Like your parents, however, it is the one circuit on my boat where the insulation broke down and began to short and smolder (which i caught before it developed into a full fire). Nigel Calder now recommends addiing a fuse (but a large one, such as 300 Amps). Others recommend a smaller fuse but in parallel to an on-off switch (so that you can isolate a blown fuse if in need of starting the engine). Others talk about slow acting fuses. So far, all i have done is add an isolator (so the circuit is only energized when the engine is running or starting). Would be interested to learn how you approached this.
I fuse but well above the likely amperage of the starter, not had one blow yet from use. I always supply spare fuses to the owner so if it did blow the fuse can be swapped out quickly.
Thank you, hope you take a look at lighting protection as it too has seen some changes.
Boats in the uk generally don’t have lightening protection systems as it’s not as common as it is in the US or other parts of the world. Worth looking at though!
Love your work, very informative. Can I ask why you use fuses on the main cables from the batteries instead of circuit breakers?
Question: When the B2B senses the full charge from the LifePo4 and starts charging the AGM with the extra power from 240v or solar, does it change the charging profile to AGM and not LifePo4?
Brilliant video, I want to do exactly the same on my moody 36. I have 300 amps of lead acid. I want to add a 320 lithium. Could you please list all the parts used apart from the battery?
WhT is the tool you used for drilling at 39:20 .? Thanks -- Edit - just found it in your tools video - thanks very useful
Great video - very inspiring - thanks
couple of questions:
How about a bilge pump connected directly to the house bank?
If you had a multi battery isolator would you ditch that and go for the dc-dc solution shown here?
Auto bilge pump is the ONLY thing attached direct to the house battery (well to the fused side of it). And yes to the second question - if I understand your system but hard to say without seeing it really
Out of interest, did you wire the windlass to the house or start bank? Most lithium battery manufacturers recommend against high current loads (not because of the battery itself - but because the BMS is set to trip out under high loads). The specs for this battery, however, state it will accept 100A continuous. What do you normally do?
There is no windlass on this boat so not really a consideration. If fitting one on this particular boat I would wire it into the house bank as the engine starter bank has a low AH rating because it’s designed to be a starter battery and provide high cca’s for its size and weight. A windlass on this size of boat would be well under 100a
George. Ive got a Beta 14hp and looking to install a new starter battery. I think you have previously metioned that Motorcyle starter batteries can be used, possibly AGM. I've got the Sterling DC to DC charger ready to go after the recommendation in this video. For my Beta 14, what Ah capacity starter AGM bat do you think I should consider getting? Is an 19Ah AGM too small? The house batteries are 2x 100Ah LiFEPO4.
Starter batts are rated with CCA (cold cranking amps) not AH as they have to deliver a high current for a short period of time. So you need to check the spec from beta. Beta 14 is a small engine so only a small starter batt is needed to spin it over
@@RefitandSail Fantastic, I'll check with the specs and consider the CCA. Cheers mucka!
Beautiful work and very precious for me. Thanks you very much. I have the same work to do on my Contessa. All the installation is from 1976 without any security (fusibles in french)
I will make exactelly the same because it is simple for me and for my boat. I don't want complicated things.
I like make electricity, because, like you, it is clean, précis. I have learn on my precedent boat a Marieholm 26 for the first time.
Do you explain in an other video how change the electrical cables of the differents cabin lights. I tried to pull them, it is impossible. And they are original. 1976 rigid every where.
I suppose there must be a lot of connections under the linings and I dont want dismantle all this and I don't like when I cannot see. I thought I'd run new cables under the fittings and reduce the number of lights....
I can't take advantage of your discouts on equipment because there are too many customs taxes for France, it's a shame.
I offer you some bears with pleasure for all your work.
Hi and thanks for the message. In my experience it is almost impossible to replace the original cables that are in the headlining so I generally have to reuse them and so far it has been ok. To pull new cables for lighting into the gap between headlining and deck is impossible. For things like the mast lights you can run new cables to the base of the mast and then replace the mast cables so that they exit at the bottom of the mast.
I hope this helps. Good luck.
Thank you
Yes it's help me a lot
So I keep the original cables
It's just I was
affraid of old connections under headlining
When I rewired my 1970's boat I found several cable routes that could not be replicated today. Had to start with brand new locations for some loads depending on where you could run the new cables.
Just wondering those battery fuses must be quite heavy duty for the starter motor what value do you use normally? 200A ? Or more ?
Remembering that the fuse is there to protect the wiring and knowing what the capacity of the wiring is you set the fuse below that. Starter motor prob pulls 80a maybe 100 but no more on a small engine like this. 150-200a fuse is fine for this application.
Another question for you George: I’ve noticed that in several of your videos, you’ve fitted these relatively small AGM starter batteries, and this video shows the model you seem to like - the Odyssey Extreme ODS-AGM40E. Looking up the specs, I see these have adequate cold cranking amps, but their rated capacity is only 45 Ah. I just completed a repower on my boat with Beta 20, and noticed they call for using a starter battery of minimum 70Ah. Do you have any concerns about this, particularly in maintaining the engine warranty coverage on your Beta repowers? (I known an under-capacity battery shouldn’t affect an engine, but sometimes companies may look for ways to protect themselves from warranty claims.)
Beyond that, another wonderful video. Your earlier videos were essential to building my own confidence to tackle my first repower single-handed. Enjoy another pint on me.
If you look at the specs for various sizes of beta they recommend the same size battery for smaller and larger engines so for the smaller size engines like a 20/25 the smaller battery will be totally fine. The reason beta give an amp-hour rating is that many boat owners use batteries that don’t have a cca rating because the are cheap flooded lead acid batts, so beta take the view that the average 70ah FLA will be capable of providing the appropriate cca’s. In reality it’s much better to state what cca’s are needed as amp hour capacity does not actually indicate how suitable it is for the job of starting at high amperage. Hope that makes sense.
I can’t believe for a second that beta would deny a warranty claim on those grounds given that I could specially choose a 70ah deep cycle battery that has low cca’s because it is designed for low draw and deep cycling. Beta are a pretty sensible company (I have spoken with the MD a few times).
No one has reported any issues on the boats where I have installed these specially designed high cca stater batteries.
Makes all the sense in the world, George!
And just to second your sentiment, the folks at Beta Marine are indeed wonderful, and eminently reasonable. I’ve only dealt with their American outpost, Beta Marine USA, but the staff there provided invaluable advice for my repower, both during the purchase process and during the installation. I think I’ve just gotten burned (or nearly burned) enough with warranty issues in the automotive world that I’ve become a bit paranoid!
@@pschwayep totally get that
This is something I had been thinking of doing on my boat. I've decided not to because it isn't worth the cost of the lithium battery. But when I was looking into it, I did wonder if the DC2DC charger would reverse charge. If not, you could put all your solar onto the starter battery, but would the charger push power into the house battery when the solar was charging the starter? Maybe the solar charger will stop when the starter is full.
I've just installed a Victron setup on the starter battery side of my engine. It's a Yanmar 1gm10 1983. Starter battery is a 72wh 350CCA Lifepo4. Because it's an old alternator I've wired it as follows: alternator to Victron Argofet (this provides a buffer between the alternator and the starter battery if the alternator decides to shut off its output). Then, the output from the Argofet goes to the Victron Orion-Tr Smart Isolated DC-DC charger (this provides the correct charging profile for the Lifepo4 starter battery). Maybe that helps you? It's an unconventional setup lol but it works. For the house battery bank I will be using solar power & a Victron MPPT. Regarding grounding, there is ONE ground wire to the engine block that runs to the negative (500A) busbar connected to the negative terminal of the starter battery. EVERYTHING start related is grounded to this busbar: accessories, gauge panel, DC-DC charger etc etc. Unfortunately you do need a ground to engine for the temperature sender and oil pressure sender, as they are grounded through the engine..
Also wanted to say, lifepo4 battery prices are coming down, not too expensive now. Well, here in Australia I recently bought 2x 120Ah LiFePO4 batteries for approx $400AUD. Only buy Lifepo4 for your boat, it's the safest option for marine environments. Don't buy any other type of lithium
Lithium batteries have continued to drop in price so may be worth investigating again. The original Sterling B2B I fitted to my boat a few years ago didn’t have the reverse charging function that the new ones do so I’m thinking of swapping it.
You could do as you say and put your renewables into the starter battery and charge the main/domestic bank from the B2B but that would be an unusual way to do it. In theory the only thing your starter bat should be there for is starting the engine so should need little more than an occasional maintenance charge which is what the reverse charge feature is ideal for.
@@RefitandSail there are some great bargains out there for lithium, prices are steadily falling. Not sure about UK but they're probably cheaper than Australian prices lol.
My setup is for the alternator to charge the starter when it's running, as it only needs a little top up now and then but 2x solar panels for the house battery bank. Victron Smart Shunt on the start battery side + the DC to DC charger let's me see the voltage of the battery at all times.
My ancient starter battery weighs more than my 120Ah LiFePO4 lol. I love lithium tech, just amazes me. Even my starter battery, it fits in the palm of my hand, just amazing. And the engine starts better than ever with it.
Did the Contessa have an old fashioned automatic combiner (which combined house & start when a charging voltage was detected) and, if so did you remove it? (It's function having been effectively replaced by the DC to DC convertor).
No, it did not even have that, as per the video it had a 1,2,both,off switch (now replaced) so the skipper had to manually select what bettery was in use/being charged which is fine if the skipper knows how the systems work but a lot of owners I work with just want a simple on/off and the charging of all banks to be automated.
Great video. Can you comment on the trend of cruisers fitting larger than normal alternators in order to obviate a generator etc?
Hard to comment really as every owner/boat has a different use case and budget. Running the boats main engine just to charge is inefficient and not great for the engine but with a chunky alternator and decent regulator the charging can be achieved relatively quickly. Some boats done have space for or the budget for a generator. Personally I would rather have renewables such as solar and wind chargers and my boat is completely self sufficient on power outside the winter months and have tons of energy to spare when in the Caribbean. I bought a small generator as a backup but literally never used it!
I am slowly increasing my solar capacity, with the goal of never having to run my generator at anchor. Up to 400W of solar but still not at break even yet. Part of the challenge for me is the tropics is difficult as days are shorter and ambient temps (ie fridge load) higher. 400W of solar would probably be more than adequate to break even in most cruising areas.
Hi, First off love your channel and watched loads of your videos. Just a quick question on this one, is there any grounding needed for the lithium battery? Also if there was an inverter fitted how/where would you ground the case?
The boat doesn’t have a grounding plate but does have a hull anode attached to the engine and by extension is connected to the battery neg. If an inverter was fitted the neg/hull anode would be the ground.
Pleased you like the vids 😊
@@RefitandSail Thank you for the reply and the extra info on an inverter. I'll have to re watch the video as I didn't see how the negative terminal of the lithium battery was connected to the engine. 👍
@@ontheriver6518I didn’t show every last detail or the video will be hours long but there the engine neg/ground is connected to the 4-stud neg bus-bar.
@@RefitandSail Ah ok that clears it up, thank you for for your time.
You mentioned that you included a manual selector (so that, in an emergency, you can combine start + house banks) but then you said you would quickly switch it back to position one (banks parallel) if the engine was running. Surely not? If you have a running engine, when you change switch position, you momentarily go through zero load, surging the alternator voltage and potentially blowing the alternator regulator diodes? Or am i missing something?
This switch does not go though “off” between “on” and “combine” so the alternator is never discounted while charging so not a problem. But you are correct in that you could never switch off an engine battery switch as it will likely blow the diodes in the alternator (depending on how it’s connected).
@RefitandSail You are quite right! Checked the Blue Seas tech specs and they confirm that it includes a 'make before break' contact design.
Great work.
Thanks!
If I wanted to use a DC/DC charger like a Victron Orion-Tr Smart, which I believe does not have the reverse capability, could I just install a single shore power charger on the engine battery?
Sure, you could do that, the only issue may be that as the voltage rises on the engine batt the dc to dc charger may then tick in and start trying to charge the domestic bank so you may need to disable the dc to dc if you are charging from 240. Hope that makes sense.
@@RefitandSail Isn't that what I would want it do? In order to keep the LiFePO4 topped off. Or should I just get a 2 bank charger, like the NOCO Genius GEN5X2? What are your thoughts on the Orion XS? This boat spends most of it's time on the dock, running the engine just to get in and out of the marina for day sailing. (Actually 120 on this side of the pond)
@@schwarz6337ah, sorry I miss understood. It’s more common to have the shore power battery charger on the domestic bank because that’s the one that gets worked hard and pulled down by the systems on the boat. There should be noting on the engine start battery apart from the engine and that recharges once the engine is running. You could do it the way you suggest but it would be slightly out of the ordinary (but it would work.
I would personally stick with the more normal arrangement and charge the domestic bank direct off the 110.
Is there a reason you are using fuses for the batteries instead of installing a separate Breaker next to them? Seems that if a fuse blows and the short is repaired one might not have a spare fuse (years down the road)?
The use of fuses rather than high amperage breakers seems to be pretty std practice, that’s not to say that we should never consider other options. I always supply a spare fuse when I do an install like this so if that is used then it’s up to the owner to ensure the spare is replaced and kept onboard.
@@RefitandSail There are exceptions, but my understanding is that breakers do not generally have a fault current rating to guarantee contact separation on a full short. They also have a tendency to become progressively more sensitive with attendant nuisance tripping. As mentioned above, main battery fuses should also be selected for a type that has sufficient fault current rating.
Why have you run the shunt to the negative of the starter battery and not the Domestic battery? Are both the negatives of the starter and domestic connected?
The shunt is reading current for the domestic batteries only, the neg for the engine battery is connected to the common neg bus bar in the battery compartment so the shunt does not register any current to and from the engine batt, only the domestic bank. However there are small voltage sensing wires to both batteries for the battery monitor to record the voltages of both batts. Hope this answers your question
That makes perfect sense. Thanks
Thanks for this long awaited video! Is there a reason why you didn't use a car-size AGM?
Yes, good question, there are AGM batts designed for deep cycle and there are AGM batts designed for starting engines and there are hybrid options. As this is a dedicated starter batt I have chosen a battery that is specifically designed for that application, it has very thin but large surface area plates so it is able to give very high CCA for its physical size. Also these are not large boats with large lockers for storing batts so a compact battery like this is a bonus and these particular batteries have proven themselves in terms of long life and performance in use. Nothing wrong with having a physically larger agm as long as it can deliver the cca’s the engine needs but no benefit really and it’s likely heavier and no point in having a larger AH capacity on a stater batt.
@@RefitandSailUnless it is also servicing the windlass load?
@@stephenburnage7687no windlass on this boat but I would run it off the house bank if there was.
Great vid George. When are the t- shirts going on sale
Working on it, you are not the first to ask…. It’s on the list of things to arrange. What this space….
Just a quick question George . Did you replace the Vetus battery selector for any particular reason , or was it purely an age thing ? didn't fit with the installation ? .
Yes because it would only allow the boat to run off one battery or the other and the starter battery is inappropriate for domestic use and vice-versa. Switching between batteries on every engine start is a PITA and I want to fit a simple and safe system where domestic loads can only come from the domestic battery and engine batt is saved from accidental use. This is a bit more idiot-proof (the owner is not an idiot, he’s a doc, bit simple systems are always best).
@@RefitandSail Thank you George . I use a Vetus switch myself , but i use it with two battery banks . I just wondered if maybe you knew , or had come across a problem i didn't know about !
Ah! Sterling will not accept an order for the battery if the shipping address is non UK mainland! Too bad!
Ahh, sorry about that.
You also could have used an DC-DC charger with engine sense to know when engine is running to charge the lithium and the starter battery.
Lifepo4 batteries are capable of very high currents in a direct short. Are you sure that that fuse is sufficient? Nigel Calder recently did a video suggesting all lifepo4 batteries should be protected with a fuse with a 20,000 AIC. Class T or HH fuses have such a rating. The American ABYC standard says use class T( class T is an American standard fuse) in Europe we have HH fuses. I built my own lithium batteries. I used HH00 fuses.
Also, I am one of the few people who has seen inside a Sterling lithium battery. In my opinion, the build quality of those batteries is very poor. Using builders foam to secure the cells is not acceptable. They look like a very poor home built battery inside. Their use of Daly BMS is also poor. Far better to look at Fogstar batteries. Quality cells and good BMS from a UK supplier. Sterling just buy in cheap Chinese batteries and stick their label on from what I can see.
I see that the new lithum house battery has 150ah of nameplate capacity. Have you figured out what % of that nameplate capacity is routinely accessible, long term?
Sorry! but my brain is hurting? Mechanical I understand ,Engines/ gearboxes/winches etc.I never thought years ago that electronics would become such a big part of our lives so became mechanical rather than electronic. but I have a gps chart plotter but my grandson has to do any programing etc etc I do enjoy your videos but this is still beyond me lol🥸🥸🥸
Yeah, I get that, I have friends that just don’t “do” electrics. I’m much the same way as I just done “do” or find it hard to learn languages. Are brains are all wired differently (no pun intended!). I try to make the explanations as simple as I can as I like simple but will be back to boat fixing in future videos or maybe even some actual sailing!!
Hit me up when you replace the engine and go all electric. Be aware of how pollution affects users of fossil fuel.
Safe lithium batteries on a boat. No thanks. I seen too many lithium battery fires. A video on putting out lithium battery fires on a boat should be made.