Hi Adam - thanks for the shout out. That's a nice tidy setup. You might be interested in my electric lawnmower which has a 7S12P recycled cell battery pack. The breaker triggers at just over 100 Amps - so the 12 parallel cells are delivering around 9 Amps each(!) So... if one cell in your setup does short circuit you could expect at least 28 Amps to go through it's fuse - more than enough to blow that 5 Amp fuse I reckon. Cheers, Paul
+Paul Kennett Yeah I expect the fuse will blow quite happily. I am conscious that the fuse may melt the solder - but either way it should disconnect a bad cell. As I said in my message to you, I may have come up with the idea myself before finding your channel but I think you deserve a lot of credit. I used many of your ideas I hadn't thought about. I forgot to mention your small blocks design though - which I believe is the best design I've seen for anyone wanting to 'go big'. The analysis and thought you've put into your videos is superb and I hope my little video (with far less of those two things) gets you a subscriber or two. Cheers Paul.
My understanding of the way fuses work is they burn in the middle of their length - because whatever they're attached to acts as a heat sink. But even so - they're tiny wee wires so you have to look carefully to actually notice if they've blown. And yes - I do seem to be picking up a few new subs. Thanks :)
That's a good point. I think I'll definitely be doing a test. I intend to keep a close eye on the fuses but if one blows I should also see a group which goes out of balance due to the decrease in capacity, so hopefully I'll notice one if not the other. The fuses being tiny wires is a concern or perhaps I should say counter intuitive. All my solar knowledge says use the thickest wire possible to avoid losses, then we go and interconnect cells with thin, high resistance wire!
I thought fuses were low resistance (ie they really are "just" a piece of wire - ?) Using thick "long" wires are to avoid voltage drop over distance - whereas a fuse has relatively short length/distance. And I agree - it feels wrong to me too :)
Sorry should have said relatively high resistance. As you say, short lengths should make a huge difference and as normal operation is pretty low current it shouldn't really cause any issue. Even so I tried to keep them all the same length and as short as I could without making it more difficult to see if they had blown.
+Adam Welch Hello. I take it the solar shed is 12V, but the above installation is still 24V. I ask as in a previous vid in the series you work out that the Viewstar 1024A Solar Charge Controller is better at handling 24V.. or have I missed something (which is likely). Thanks!
Yes the main system in the solar shed is 12 volts. In the first video in this series I looked at doing a 12 volt lithium pack but for me the numbers just don't work out. In a 3s pack you need to charge close to the limit, in a 4s pack your discharging too low. 7s is almost perfect. A 24 volt charge controller will typically boost charge to 28 volts - 4v per cell average. It'll disconnect when the cells drop to a fairly comfortable 22 volts - 3.1v per cell average. Now you can get a charge controller which allows you to edit the charging settings, but I wanted to use an off the shelf lead acid charge controller - they're cheap, reliable and plentiful. I find it does an excellent job. I've found that most charge controllers sold for lithium tend to hold the cells at float usually at 4.2v per cell. I don't think this is sensible because we are leaving very little margin for error, and I like my shed and don't want it burning to the ground! I do end up converting the lithium pack output back down to 12 volt to use with my led lights - so sadly there are some losses and currently I've only a very small buck converter attached so can't push those cells too hard.
+ Adam Welch, I've pop riveted the holders, placed my copper bus bar and am finally abeam the runway to land this project! I was thinking of adding a switch, maybe something like this: www.maplin.co.uk/p/ip65-rated-illuminated-24v-dpst-rocker-switch-green-n56ka. Kind regards!
Very nice setup - looking forward to seeing how this performs over time. We had a good supply of old laptop batteries for 18650s in local surplus shops until recently but with the popularity of e-bike diy battery folks and this kind of application recycled cells are getting scarce. But then new cells are getting cheaper...
Great update. I'm just planning on something like this for in my garage to run lights, etc. Also building packs for another project, so repackr.com was a great find! I'd had a hunt round a few months ago and found nothing.
Thanks Darren. It's a very handy site. It's interesting though because it doesn't always come up with the same pack design. Keep hitting submit and record all the results, you'll find a configuration you feel most happy with.
I was wondering if you were thinking of maybe a 1Kwh pack build. Which would give you lots of power for your shed even on cloudy or panel covered days. This would be a great next step to battery bank. Great Video Cheers Eric
+Eric Scherzinger No plans as yet. I prefer 12 volt systems really (and I don't think a 3s system is ideal for 12 volt) but if someone offered me a boat load of laptop batteries for very little money it would keep me busy wouldn't it. :-)
nice video, i have started messing with these cells myself, im making an electric skateboard battery at the moment. i must say you got lucky with your cells. mine seem to average about 1600 mah per cell
+Kris Harbour Thanks Kris. Yes I was lucky... I've mentioned in one of the threads that I knew the history behind all of these pink Samsung cells. Very little use but they must be six years old. Pretty high capacity but it's also worth mentioning I tested them at a 500ma discharge rate and I know many check theirs at 1amp. Best of luck with your skate board project - my skateboarding years are behind me now I think :-)
i did test mine at 1 amp. that little charger/discharger looks like a great little tool to do this. it means you can just leave them alone and so you can discharge at a lower current. very good idea. the cells i am using are old laptop battery packs from ebay. i had some really good one with the same pink samsung cells you had in the video but i had alot of red sanyo cells that were like 400mah. anyway, thanks again for the great video. keep up the good work my friend.
+Chris Bird Thanks Chris. I did see your name was behind the site so thank you for that too - it's a really useful service. Any chance you could explain why you get different results if you submit the form multiple times, and perhaps your opinion as to which might be the best option given by the site?
Adam Welch the algorithm randomly chooses a solution, then keeps trying to change the solution, if it finds something better it keeps it to build on it throws it away and tries again. It's done like this because trying every permutation of the cells for the best fit would take quite a while to process. So each time you try it you get a different solution but any solution it does give should be good enough. Yes, it was something that Paul, myself and one of his subscribers pulled together. The second option provided for sorting really isn't that useful. it tries to make sure batteries grouped together are very similar capacities, but leads to lots of wasted cells if the capacities are not very similar to each other. it's something you could do just by grouping the cells into boxes as you tested them.
ZOMG where was this website months ago when I needed it?? I made a 12S lipo pack out of 130+ 18650 cells for my ebike project and manually sorted them all in excel. Oh the headaches lol....
What a cracking video. I'm going to try and follow it to the letter. Might have to watch it a few times. Unless there is a diagram available. Just bought some batteries. Ordered some of the other bits of Flea bay. Fascinates me the whole 18650 solar thing.
Thank you very much. Good luck with your project. No diagram I'm afraid but it is fairly standard and hopefully I've explained it enough in the series of videos. Cheers
Awesome video Adam! I also really like the links to all the goodies in the text underneath the video, well done and easy to find the stuff you need and refer to. I wonder what output you get during these crappy solar (rain) days?
+Luc Peeters I'm glad you're finding the links useful - I'm trying to do links to searches so people can find the best option for them. Not all sellers post everywhere and it may be you'd rather use a local stockist sometimes. I can monitor my lead acid setup from work. Today I was getting about 2 watts from 200! Thanks for the kind comments.
Fantastic video series Adam. I had wondered if a lead acid charge controller could safely charge lithium batteries. It got me thinking whether it is possible to setup a 48v (14s) lithium pack with 48v solar charger.
Great post Adam. Good that you're exploring the potential of recycled 18650s a bit further. Looking forward to seeing where you take it, as your sharing always has new insights for me, as you draw on your own knowledge and perspective. I'm a big fan of Paul Kennett also, and the broader DIY PowerWall community. Q. For a sense of scaling for our similar climates, how many lights (total wattage) are you running/planning to run off that 18650 pack? Have you those lights on a timer or sensor? What size panel is charging the pack? (just general curiosity for my own build). You have realised, that keeping the 18650s in pairs is a big advantage, and will make doubling the capacity of your current build a doddle (when you find your next haul of battery packs - now that you have the bug!). :-) Ivor
Thanks Ivor. I'm not going to be trying to run my house (or at this point even the shed) from recycled cells - they seem to be harder to get hold of than I expected. On the outside of my shed I have two multicoloured LED lamps which were sold as 10 watt but actually use three 3 watt leds to generate different colours - I hope to run them for 2-3 hours a night. I also want to put my two 10 watt LED security lights and a PIR sensor on them. Now as you'll expect, it's hard to say how often and for how long these lights will be drawing current. It depends on activity in the garden... and we have a cat who likes to set it off! I'm waiting for a more powerful (but hopefully still fairly efficient) buck converter to arrive as the little one I have now is close to it's limit which is why only the multicoloured lights are connected so far.
Have you considered NiHM cells? They give a higher energy and power density than lead-acid, if not so much as li-ion, but they can also last a lot longer and are comparatively easy to manage charging for.
+Vyl Bird I think you asked me this before? It's an option for some but I don't have a load of NiMH cells lying about. If I did I'd definitely try to use them for something.
hello! I am about to make this setup. any problems with yours? still working fine? btw, manual included in my model say: new balance function - long press the first key lipo/life/liio will blink, says it is in balance, balance process according to the second button can view each battery voltage, balance is take the battery in the lowest section as the benchmark to discharge balance
scan of the manual here postimg.org/gallery/130oij1xs some LED drivers allow a larger range. 12VDC to 30VDC or more (seek on aliexpress). they can work direct without the DC2DC converter
Good video as ever, btw did you spot that in the latest version of the EPEver monitoring software now has a lithium option. It still lists float however so not sure if it's disabling it or not. It's interesting it mentions cells in series 3 or 6 if memory serves but without any individual cell monitoring by it i'm not sure why it's got it listed in the settings.
Thanks Colin. I thought I'd updated the software last week after I watched your video. As it happens it's not updated at all and I've had to remove the old and install again. Now I see the lithium option. It's a good question regarding the float settings, and also regarding the cell series count. As you know I just don't think 3S is really compatible with a 12 volt system, and therefore neither is 6s with 24. Seems odd. To remove the float out of the charging profile I suspect the controller might need a firmware upgrade (unless it was designed in from the start). It would be very interesting to see if this is possible moving forward with the Tracer A, or whether this is something EPSolar will bring into new products. Thanks again.
Hi Adam, relative to the charge controler you are using isnt the negative comon between all and each channel from 1 to 7 conected to the positive side of each cell? Thanks
I found that bit quite easy. The solder took to the battery holder well and the fuse wire is very thin. There are some issues with soldering fuse wire (the heat can degrade the fuse wire, and potentially when the fuse wire is getting close to fusing, it will be hot and might melt the solder) but I think it's worth trying this for a little while. A good tip from Paul Kennett I forgot to mention was to tilt your battery holders to ensure the solder doesn't flow down the connector to where the battery will make contact as it could make it harder to plug and unplug your cells.
@@AdamWelchUK I just built a similar pack using these battery holders. Only I did a 4s4p. Instead of using fuse wires I had some 2cm long thin nickle plated tabs I bent over in half and stuck in between behind the battery holder contacts connecting pos to neg. Seems to work like a champ. No soldering. (Well, except for soldering the tabs to the bus bar. Tried some copper but couldn't get a good hold. So I doubled up nickle plated strip to use as a bus bar.) Batteries hold it all snuggly in place. Now to connect to a PWM charge controller that says it can also charge lithium. We'll see.
Hi Adam, don't you think that the (increasing) humidity in the wood will eventually cause some current leakage through the busbars ? Maybe you should have isolated them from the wood.
I had a thought,don't know if its a good one. If you had 4 Capacity Controllers and arranged the cells so that you had four sets of seven cells in series. Couldn't you monitor and balance charge each cell individually ? Was wondering if that would work. Thanks for the videos, keep up the great work.
You could effectively make four 7s1p packs which you then put in parallel but except for the issue of one cell going bad and bringing the others down there is little advantage - and creates a fair bit of extra cabling. Actually if one cell went in the middle of a string of seven the voltage of the series set would drop dramatically and the other good 7s1p strings would try to charge that string. You'd need to fuse each string for this eventuality so you are kind of back where you started.
I did notice its easy to put a battey in the wrong way around, but with 12v it doesn't matter as much because it just doesn't work, so a short circuit owuld just make the 12v into 7.4v??
I'm not too worried about the charge controller efficiency. The MPP of the panels isn't too much higher than the typical voltage of the cells. It's PWM but it's only got 100 watts of solar attached (and it's winter) so I suspect the capability of the array might be more of an issue - we'll have to see. Today is a dreary wet day and my lead acid setup is only achieving 1-2% of it's rated. The expansion is more around riding the bad days as long as there is a good day in every three or four!
Hi Adam, great _series_ of battery vids. Thanks! Bit con-fused. (Sorry...). You started out with a 24v rig of cells, using a 24v chargeController. Then built a set of seven*four cells for 7x12v? Connected to same 24v controller. With balancer showing 27ish volts. Please explain? ;)
+Mark T I use a step down converter on the load output of the charge controller to bring the 7s 24 volt battery voltage down the 12 volts which is more useful for me in the shed. Cheers.
Hi Adam, Would you recommend to use the same setup as you did? I am planning on building the same size setup, I already gathered 18650's. Seems like an affordable and relatively well functioning setup. I've seen many different setuos from many different youtubers but they seem to have a different budget in mind....
+KaBBBram Yes most people are doing much bigger projects. This system is working beautifully. PWM is fine as long as you don't want to use lots of power during the day. Just consider your charge controllers day to day top charge and unless you have extremely similar cells pop some active balancing on there. The capacity controller does a superb job for less than $5!
Btw, I had one more question. The EPever controllers are relatively high priced. Is it necessery to buy the EPever controllers when using lithium cells or are the cheaper PWM controllers fine too?
+KaBBBram A cheaper one may well do the job perfectly. Pay close attention to a charge controllers 'boost' charge voltage and it's float voltage. If you go ahead with one keep a close eye on it the first few days. You want to make sure it does exactly what you expect. I think the charge controller needs to charge fully up until the boost voltage and then hold it there for a little while (EPEver is 60 mins by default I think). Then it needs to stop charging completely until the voltage of the pack drops to the float level - which unless you are using the power in the day will mean that no charge goes into the cells until the next day. It's how mines been working now for about a year.
There's now li-ion charge controllers. I'm going to give this one a try. www.ebay.com/itm/10A-12V-24V-LCD-Solar-Charge-Controller-for-Solar-Panel-Lithium-Battery-Lamp-WN8/182720515890?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
i need made same power wall. i has orden now capsity controller, i not found were can buy balance 7 cel wire connector. and solarcharger what model can use whti li-ion battery, i come 2 panel now first and later i adding more panels. and need use 12V all my house light and some 12 volt machines sometime.
Hi Adam. I am new to the 18650 craze and have been watching all your videos and those of others who are working with these cells. One major thing they all have in common is the use of fusing wire between cells. My understanding is that each 18650 has a circuit underneath the top cover that is in essence a fuse. So are the fuse wires being used as a redundancy am I confused about the cells own built in protection? Thanks and I am really learning a lot on your channel. Very watchable and covers the material very well!
Thanks fpr your reply. I have completed the wiring as according to your layout. But when I charge the 18650 battery, there is some huming noise coming out from the battery pack. What seems to be the cause and is it normal ? Appreciate a prompt reply. Thanks again.
+Lau Weng Yew No that doesn't sound normal at all. Something is wrong but it's hard to tell what from a short description I'm afraid. Can you narrow down the noise?
+Lau Weng Yew Its actually two 12 volt panels in series making one 34v panel. They are 50 watts each. Generally plenty to keep the bank topped up as I'm not drawing much.
Hi Adam, i have a simple question for you or anyobody else that can point some light. I want to change my old baterry system AGM or lead acid batteries to 18650 batteries (i have plenty of them to start) My system is 150w (3 x 50w panels in parallel) that gives 19V and from the charge 20A 12V controller it is connected to a 12V battery cause i use it for led lights and charge sometimes a 85w laptop (with an inverter). The battery is 100AH lead acid battery that soon i will have to replace cause doesn't really hold good charge anymore. My main problem is that is too heavy (around 35KG!) and i live somewhere that there is no way to reach via a car so i will have to carry (did this before and i do not thing i can do again) . So i am wondering based on my math if i connect 50 cells of 2.000mah 18650 batteries then i will have the same capacity like the old lead acid battery? And of course better discharge rate etc. Or there is something else that i do not understand and is not that simple as it sounds!?
Hi thumbs up on all ur videos,, very interesting,, I have a poor electronic basics skill and trying to learn enough to build a battery for a ebike project in the future from 18650 cells,, I buy bits and bobs and haven't got a clue were to put wires from and were to ,,for instance just got a small cell checker capacity like urs ,,no instructions on the pin outs of what's what ,, anywhere I will find this info please on the inter web many thanks Shane warks uk
+Timothy SKing Well I work in IT so I'm able to collect any batteries before we recycle the laptops. Unfortunately however I don't get my hands on great numbers. Recently a I bought a job lot on eBay - which I'm currently processing.
I have about 100 or so LiIon batteries, and have been testing them manually. While discharging, the previous battery charged up the next battery, and with a little charging by solar panel I have tested MANY batteries now. I had different equipment with these 18650 batteries, and many laptop packs. Bt if I look at the the end what I got, it is not very well. The ones below 1 amp hour are obviously very old or much used, I will keep those for experimenting. I think I have about 30 of those. Then between 1.1 .. 1.0 Amp hour I have really a lot batteries. The ones above 2.0 is just a few (perhaps 30 or so). But most are in 1.1..1.9 Ah, and the 2.x range does not get above 2.3 Ah. Even the Samsung ones and even unused ones. So I have the impression your batteries are overrated (or mine underrated). I use a charger of the same brand you have (I happen to have 2 of those, the lii-100). Any how. Nice project. I will start something similar when I am done testing all batteries, so I know what I can do with it. I do think I might try something different though, which is good so other people can see how well that will work! I will parallel the battery packs when charging. so that I am absolutely sure they are balanced perfectly. And use a dc2dc controller to lower the input (solar) voltage down to 4.0 Volts. I know the dc2dc converters will loose some power on efficiency, but not needing a balancer is something I really want to see and test. The downside is you can't use the pack while charging, how ever if need be? A second dc2dc converter can boost up the parallel'ed batteries and provide the high voltage if and when needed.
All those pink Samsung cells came out of laptop batteries of which I know the full history. They were in netbooks manufactured in 2010. All of these netbooks sat for a couple of years in storage before their first use. They sadly had very little use before the netbooks were taken out of service because of broken screens, keyboards, hard drives etc. 99% of the 18650s were fine and had been through very few cycles. I've found my LiitoKala Engineer li-300 to be pretty accurate in it's calculations benchmarking it against my own discharging arduino project. The thing that perhaps I should have mentioned is that most people on YT seem to be discharging at 1amp, and the littokala does it as only 500mA. A longer slower discharge will probably give slightly better capacity values, but equally the way I'm using them the discharge in actually use will be even lower. However in many respects the mAh figure is simply a benchmark. You just need to get the right balance in your packs. You can test it's true capacity in other ways and reduce the margin for error once the whole pack is built and running. My pack only has outside lights attached, so they charge in the day and discharge after dark. This should hopefully ensure they give a long service life. Having my 7s pack (and a 24 volt solar panel system charging it) allows me to only convert once as apposed to your buck and boost. It should be a little more efficient, but does add the balancing complication into the mix. Thanks for your comments - good luck with your project.
A bit confused about the fuse wire. I was under the impression that the series connections should be a heavier gauge wire while the parallel connection uses the fuse wire.
Yes often this will be the case and I guess mine are done like that too. If you imagine that each cell has a five amp lower gauge connection. In normal operation each series group has four of these 5 amps connections to the cell series group - so this is a heavier gauge wire. So from one series group to the next there is a 20amp connection, and from each cell in a group there is 5 amp fuse protection. It's worth noting my pack only charges at about 2.8 amp maximum and discharges a lot lower than that so high current interconnections aren't really something I need.
The fuses between each group of cells is simply to protect the other cells in a group if one of the cells goes short circuit. Lets say cell two in a group of four goes short circuit. The other three cells will discharge through this short circuit from their positive to their negative. So the fuse attached to the shorted cell should blow. The other three cells will continue to work as they should now the short has been removed. Although obviously we've now got a weak group of cells that will find it hard to keep balanced with the other groups.
Hi Adam, nice update video. Maybe you could also attach an Arduino with some WiFi to monitor the cells remotely, and put it on a webpage so we could also enjoy it.
I have once run across laptop batteries where a pair had one dead cell and one good cell. I believe each cell should be treated separately for safety reasons
The fuse wires are for protecting each individual cell. If one of the four in series goes short circuit or needs it's neighbours to deliver lots of current to it the fuse on the damaged cell should blow. That way the battery pack keeps running but the bad cell is taken out of the equation. I might look in the future at demonstrating that. Or have I miss understood your point? Sorry if that is the case.
sorry I had forgot about the balance strip making each pack parallel my idea was to make it simpe each cell is 2ah that 8ah per parallel pack one bettery fails that means your left with 6 8ah packs and 1 6ah pack that will over charge my idea is they are in series string with a fuse on the end this way if a cell goes bad that brings the hole set of banks down to 6ah rather then mixed ah rating of a pack due to bad cell
+David Simpson I see what you mean. Yes with this method there will be one group with a lower capacity but I'd hope I'd notice before it becomes an issue. Interesting idea you've got there though. Effectively lots of 7s1p packs strung together. Cheers
Hi Adam - thanks for the shout out. That's a nice tidy setup.
You might be interested in my electric lawnmower which has a 7S12P recycled cell battery pack. The breaker triggers at just over 100 Amps - so the 12 parallel cells are delivering around 9 Amps each(!) So... if one cell in your setup does short circuit you could expect at least 28 Amps to go through it's fuse - more than enough to blow that 5 Amp fuse I reckon. Cheers, Paul
+Paul Kennett Yeah I expect the fuse will blow quite happily. I am conscious that the fuse may melt the solder - but either way it should disconnect a bad cell.
As I said in my message to you, I may have come up with the idea myself before finding your channel but I think you deserve a lot of credit. I used many of your ideas I hadn't thought about. I forgot to mention your small blocks design though - which I believe is the best design I've seen for anyone wanting to 'go big'. The analysis and thought you've put into your videos is superb and I hope my little video (with far less of those two things) gets you a subscriber or two.
Cheers Paul.
My understanding of the way fuses work is they burn in the middle of their length - because whatever they're attached to acts as a heat sink. But even so - they're tiny wee wires so you have to look carefully to actually notice if they've blown.
And yes - I do seem to be picking up a few new subs. Thanks :)
That's a good point. I think I'll definitely be doing a test. I intend to keep a close eye on the fuses but if one blows I should also see a group which goes out of balance due to the decrease in capacity, so hopefully I'll notice one if not the other.
The fuses being tiny wires is a concern or perhaps I should say counter intuitive. All my solar knowledge says use the thickest wire possible to avoid losses, then we go and interconnect cells with thin, high resistance wire!
I thought fuses were low resistance (ie they really are "just" a piece of wire - ?) Using thick "long" wires are to avoid voltage drop over distance - whereas a fuse has relatively short length/distance. And I agree - it feels wrong to me too :)
Sorry should have said relatively high resistance. As you say, short lengths should make a huge difference and as normal operation is pretty low current it shouldn't really cause any issue. Even so I tried to keep them all the same length and as short as I could without making it more difficult to see if they had blown.
Fantastic upgrade. That's one hell of a battery pack!
+Gadget Addict Thanks. About 256 Watt hours I think. :-)
Hey thanks for the shout out. Big fan of Paul's too.
+NERDVille No worries. I enjoy your channel. Cheers.
+Adam Welch Hello. I take it the solar shed is 12V, but the above installation is still 24V. I ask as in a previous vid in the series you work out that the Viewstar 1024A Solar Charge Controller is better at handling 24V.. or have I missed something (which is likely). Thanks!
Yes the main system in the solar shed is 12 volts. In the first video in this series I looked at doing a 12 volt lithium pack but for me the numbers just don't work out. In a 3s pack you need to charge close to the limit, in a 4s pack your discharging too low. 7s is almost perfect. A 24 volt charge controller will typically boost charge to 28 volts - 4v per cell average. It'll disconnect when the cells drop to a fairly comfortable 22 volts - 3.1v per cell average. Now you can get a charge controller which allows you to edit the charging settings, but I wanted to use an off the shelf lead acid charge controller - they're cheap, reliable and plentiful. I find it does an excellent job. I've found that most charge controllers sold for lithium tend to hold the cells at float usually at 4.2v per cell. I don't think this is sensible because we are leaving very little margin for error, and I like my shed and don't want it burning to the ground!
I do end up converting the lithium pack output back down to 12 volt to use with my led lights - so sadly there are some losses and currently I've only a very small buck converter attached so can't push those cells too hard.
+ Adam Welch, I've pop riveted the holders, placed my copper bus bar and am finally abeam the runway to land this project! I was thinking of adding a switch, maybe something like this: www.maplin.co.uk/p/ip65-rated-illuminated-24v-dpst-rocker-switch-green-n56ka. Kind regards!
Very nice setup - looking forward to seeing how this performs over time. We had a good supply of old laptop batteries for 18650s in local surplus shops until recently but with the popularity of e-bike diy battery folks and this kind of application recycled cells are getting scarce. But then new cells are getting cheaper...
Thank you. I'll do an update when there's a few bits to talk about. With any luck it'll work happily and there wont be much to say!
Great update. I'm just planning on something like this for in my garage to run lights, etc.
Also building packs for another project, so repackr.com was a great find! I'd had a hunt round a few months ago and found nothing.
Thanks Darren. It's a very handy site. It's interesting though because it doesn't always come up with the same pack design. Keep hitting submit and record all the results, you'll find a configuration you feel most happy with.
I was wondering if you were thinking of maybe a 1Kwh pack build. Which would give you lots of power for your shed even on cloudy or panel covered days. This would be a great next step to battery bank. Great Video Cheers Eric
+Eric Scherzinger No plans as yet. I prefer 12 volt systems really (and I don't think a 3s system is ideal for 12 volt) but if someone offered me a boat load of laptop batteries for very little money it would keep me busy wouldn't it. :-)
nice video, i have started messing with these cells myself, im making an electric skateboard battery at the moment. i must say you got lucky with your cells. mine seem to average about 1600 mah per cell
+Kris Harbour Thanks Kris. Yes I was lucky... I've mentioned in one of the threads that I knew the history behind all of these pink Samsung cells. Very little use but they must be six years old. Pretty high capacity but it's also worth mentioning I tested them at a 500ma discharge rate and I know many check theirs at 1amp. Best of luck with your skate board project - my skateboarding years are behind me now I think :-)
i did test mine at 1 amp. that little charger/discharger looks like a great little tool to do this. it means you can just leave them alone and so you can discharge at a lower current. very good idea. the cells i am using are old laptop battery packs from ebay. i had some really good one with the same pink samsung cells you had in the video but i had alot of red sanyo cells that were like 400mah. anyway, thanks again for the great video. keep up the good work my friend.
Great video, nice to see people finding repackr.com useful :)
+Chris Bird Thanks Chris. I did see your name was behind the site so thank you for that too - it's a really useful service. Any chance you could explain why you get different results if you submit the form multiple times, and perhaps your opinion as to which might be the best option given by the site?
Adam Welch the algorithm randomly chooses a solution, then keeps trying to change the solution, if it finds something better it keeps it to build on it throws it away and tries again. It's done like this because trying every permutation of the cells for the best fit would take quite a while to process. So each time you try it you get a different solution but any solution it does give should be good enough. Yes, it was something that Paul, myself and one of his subscribers pulled together. The second option provided for sorting really isn't that useful. it tries to make sure batteries grouped together are very similar capacities, but leads to lots of wasted cells if the capacities are not very similar to each other. it's something you could do just by grouping the cells into boxes as you tested them.
+Chris Bird That's really helpful thanks Chris. Great to hear of the collaboration too - it's nice to see the community pulling together.
ZOMG where was this website months ago when I needed it?? I made a 12S lipo pack out of 130+ 18650 cells for my ebike project and manually sorted them all in excel. Oh the headaches lol....
+Fishmonger ! Repackr is very handy.
What a cracking video. I'm going to try and follow it to the letter. Might have to watch it a few times. Unless there is a diagram available. Just bought some batteries. Ordered some of the other bits of Flea bay. Fascinates me the whole 18650 solar thing.
Thank you very much. Good luck with your project. No diagram I'm afraid but it is fairly standard and hopefully I've explained it enough in the series of videos. Cheers
Awesome video Adam! I also really like the links to all the goodies in the text underneath the video, well done and easy to find the stuff you need and refer to.
I wonder what output you get during these crappy solar (rain) days?
+Luc Peeters I'm glad you're finding the links useful - I'm trying to do links to searches so people can find the best option for them. Not all sellers post everywhere and it may be you'd rather use a local stockist sometimes.
I can monitor my lead acid setup from work. Today I was getting about 2 watts from 200!
Thanks for the kind comments.
Hi Adam love this series, I'm curious as too where too get these fuses? Please and thank you
Fantastic video series Adam. I had wondered if a lead acid charge controller could safely charge lithium batteries. It got me thinking whether it is possible to setup a 48v (14s) lithium pack with 48v solar charger.
Great post Adam. Good that you're exploring the potential of recycled 18650s a bit further. Looking forward to seeing where you take it, as your sharing always has new insights for me, as you draw on your own knowledge and perspective. I'm a big fan of Paul Kennett also, and the broader DIY PowerWall community.
Q. For a sense of scaling for our similar climates, how many lights (total wattage) are you running/planning to run off that 18650 pack? Have you those lights on a timer or sensor? What size panel is charging the pack? (just general curiosity for my own build).
You have realised, that keeping the 18650s in pairs is a big advantage, and will make doubling the capacity of your current build a doddle (when you find your next haul of battery packs - now that you have the bug!). :-)
Ivor
Thanks Ivor. I'm not going to be trying to run my house (or at this point even the shed) from recycled cells - they seem to be harder to get hold of than I expected.
On the outside of my shed I have two multicoloured LED lamps which were sold as 10 watt but actually use three 3 watt leds to generate different colours - I hope to run them for 2-3 hours a night. I also want to put my two 10 watt LED security lights and a PIR sensor on them. Now as you'll expect, it's hard to say how often and for how long these lights will be drawing current. It depends on activity in the garden... and we have a cat who likes to set it off!
I'm waiting for a more powerful (but hopefully still fairly efficient) buck converter to arrive as the little one I have now is close to it's limit which is why only the multicoloured lights are connected so far.
A most excellent series of videos!
Many thanks :oD
+Spikey DaPikey Thank you very much.
Have you considered NiHM cells? They give a higher energy and power density than lead-acid, if not so much as li-ion, but they can also last a lot longer and are comparatively easy to manage charging for.
+Vyl Bird I think you asked me this before? It's an option for some but I don't have a load of NiMH cells lying about. If I did I'd definitely try to use them for something.
hello! I am about to make this setup. any problems with yours? still working fine?
btw, manual included in my model say: new balance function - long press the first key lipo/life/liio will blink, says it is in balance, balance process according to the second button can view each battery voltage, balance is take the battery in the lowest section as the benchmark to discharge balance
+FIGUEIRINHA novos e usados Yes it's been working very well thanks. Thanks also for the statement in your manual - nice to see it documented :-)
scan of the manual here postimg.org/gallery/130oij1xs
some LED drivers allow a larger range. 12VDC to 30VDC or more (seek on aliexpress).
they can work direct without the DC2DC converter
+FIGUEIRINHA novos e usados Cheers. Thank you very much.
Good video as ever, btw did you spot that in the latest version of the EPEver monitoring software now has a lithium option. It still lists float however so not sure if it's disabling it or not. It's interesting it mentions cells in series 3 or 6 if memory serves but without any individual cell monitoring by it i'm not sure why it's got it listed in the settings.
Thanks Colin. I thought I'd updated the software last week after I watched your video. As it happens it's not updated at all and I've had to remove the old and install again. Now I see the lithium option. It's a good question regarding the float settings, and also regarding the cell series count. As you know I just don't think 3S is really compatible with a 12 volt system, and therefore neither is 6s with 24. Seems odd.
To remove the float out of the charging profile I suspect the controller might need a firmware upgrade (unless it was designed in from the start). It would be very interesting to see if this is possible moving forward with the Tracer A, or whether this is something EPSolar will bring into new products. Thanks again.
Hi Adam, relative to the charge controler you are using isnt the negative comon between all and each channel from 1 to 7 conected to the positive side of each cell?
Thanks
Nice video. Is it hard to solder a fuse wire to the edge of battery holder?
I found that bit quite easy. The solder took to the battery holder well and the fuse wire is very thin. There are some issues with soldering fuse wire (the heat can degrade the fuse wire, and potentially when the fuse wire is getting close to fusing, it will be hot and might melt the solder) but I think it's worth trying this for a little while.
A good tip from Paul Kennett I forgot to mention was to tilt your battery holders to ensure the solder doesn't flow down the connector to where the battery will make contact as it could make it harder to plug and unplug your cells.
@@AdamWelchUK I just built a similar pack using these battery holders. Only I did a 4s4p. Instead of using fuse wires I had some 2cm long thin nickle plated tabs I bent over in half and stuck in between behind the battery holder contacts connecting pos to neg. Seems to work like a champ. No soldering. (Well, except for soldering the tabs to the bus bar. Tried some copper but couldn't get a good hold. So I doubled up nickle plated strip to use as a bus bar.) Batteries hold it all snuggly in place. Now to connect to a PWM charge controller that says it can also charge lithium. We'll see.
Nice work (series) dude, thanks.
Hi Adam,
don't you think that the (increasing) humidity in the wood will eventually cause some current leakage through the busbars ?
Maybe you should have isolated them from the wood.
+Hans Struik I hadn't thought of that no. It's a possibility. I might be able to get something under two of the three. Thanks for the suggestion.
I had a thought,don't know if its a good one. If you had 4 Capacity Controllers and arranged the cells so that you had four sets of seven cells in series. Couldn't you monitor and balance charge each cell individually ? Was wondering if that would work. Thanks for the videos, keep up the great work.
You could effectively make four 7s1p packs which you then put in parallel but except for the issue of one cell going bad and bringing the others down there is little advantage - and creates a fair bit of extra cabling. Actually if one cell went in the middle of a string of seven the voltage of the series set would drop dramatically and the other good 7s1p strings would try to charge that string. You'd need to fuse each string for this eventuality so you are kind of back where you started.
I did notice its easy to put a battey in the wrong way around, but with 12v it doesn't matter as much because it just doesn't work, so a short circuit owuld just make the 12v into 7.4v??
Nice one Adam, well articulated and a great help👍👍👍👍👍👍👍👍👍👍👍
Lots of thumbs up
+Dean Greenhough Cheers :-)
Nice little setup. My only concern would be the efficiency of the PWM Charge controller. are you planning to upgrade the charge controller?
I'm not too worried about the charge controller efficiency. The MPP of the panels isn't too much higher than the typical voltage of the cells. It's PWM but it's only got 100 watts of solar attached (and it's winter) so I suspect the capability of the array might be more of an issue - we'll have to see. Today is a dreary wet day and my lead acid setup is only achieving 1-2% of it's rated. The expansion is more around riding the bad days as long as there is a good day in every three or four!
mppt only come into there own when your running a 24v+ solar array but a 12 volt battery bank
Nice setup. You have inspired me to try and do something similar of my own, keep up the great videos.
Thank you Mark.
Hi Adam, great _series_ of battery vids. Thanks! Bit con-fused. (Sorry...). You started out with a 24v rig of cells, using a 24v chargeController. Then built a set of seven*four cells for 7x12v? Connected to same 24v controller. With balancer showing 27ish volts. Please explain? ;)
+Mark T I use a step down converter on the load output of the charge controller to bring the 7s 24 volt battery voltage down the 12 volts which is more useful for me in the shed. Cheers.
Hi Adam,
Would you recommend to use the same setup as you did? I am planning on building the same size setup, I already gathered 18650's. Seems like an affordable and relatively well functioning setup. I've seen many different setuos from many different youtubers but they seem to have a different budget in mind....
+KaBBBram Yes most people are doing much bigger projects. This system is working beautifully. PWM is fine as long as you don't want to use lots of power during the day. Just consider your charge controllers day to day top charge and unless you have extremely similar cells pop some active balancing on there. The capacity controller does a superb job for less than $5!
Thanks for the reply! I will be trying that for sure.
I've been finding your content very helpful and entertaining.
Btw, I had one more question.
The EPever controllers are relatively high priced.
Is it necessery to buy the EPever controllers when using lithium cells or are the cheaper PWM controllers fine too?
+KaBBBram A cheaper one may well do the job perfectly. Pay close attention to a charge controllers 'boost' charge voltage and it's float voltage. If you go ahead with one keep a close eye on it the first few days. You want to make sure it does exactly what you expect. I think the charge controller needs to charge fully up until the boost voltage and then hold it there for a little while (EPEver is 60 mins by default I think). Then it needs to stop charging completely until the voltage of the pack drops to the float level - which unless you are using the power in the day will mean that no charge goes into the cells until the next day. It's how mines been working now for about a year.
There's now li-ion charge controllers. I'm going to give this one a try. www.ebay.com/itm/10A-12V-24V-LCD-Solar-Charge-Controller-for-Solar-Panel-Lithium-Battery-Lamp-WN8/182720515890?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
i need made same power wall. i has orden now capsity controller, i not found were can buy balance 7 cel wire connector. and solarcharger what model can use whti li-ion battery, i come 2 panel now first and later i adding more panels. and need use 12V all my house light and some 12 volt machines sometime.
Hi Adam. I am new to the 18650 craze and have been watching all your videos and those of others who are working with these cells. One major thing they all have in common is the use of fusing wire between cells. My understanding is that each 18650 has a circuit underneath the top cover that is in essence a fuse. So are the fuse wires being used as a redundancy am I confused about the cells own built in protection? Thanks and I am really learning a lot on your channel. Very watchable and covers the material very well!
Looks nice and clean :) another good video
+Mikes DIY Tesla Powerwall Thanks Mike :-)
Thanks fpr your reply. I have completed the wiring as according to your layout. But when I charge the 18650 battery, there is some huming noise coming out from the battery pack. What seems to be the cause and is it normal ? Appreciate a prompt reply. Thanks again.
+Lau Weng Yew No that doesn't sound normal at all. Something is wrong but it's hard to tell what from a short description I'm afraid. Can you narrow down the noise?
What is the capacity of your solar panel used yo connect to the PWM. Is it a 12v 200W ?
+Lau Weng Yew Its actually two 12 volt panels in series making one 34v panel. They are 50 watts each. Generally plenty to keep the bank topped up as I'm not drawing much.
Even if a cell shorts and blows the 5A fuse won't the other cells in parallel still be able to deliver current to it through the nickel tabbing wire?
Do you only have the nickel tabbing wire behind the contacts on one side of each plastic tray?
So if I wanted to use a 7s balance board how would I wire that up? I'm sorry I'm new and looking to swap our my lead acids for 18650s
Hi Adam, i have a simple question for you or anyobody else that can point some light. I want to change my old baterry system AGM or lead acid batteries to 18650 batteries (i have plenty of them to start) My system is 150w (3 x 50w panels in parallel) that gives 19V and from the charge 20A 12V controller it is connected to a 12V battery cause i use it for led lights and charge sometimes a 85w laptop (with an inverter). The battery is 100AH lead acid battery that soon i will have to replace cause doesn't really hold good charge anymore. My main problem is that is too heavy (around 35KG!) and i live somewhere that there is no way to reach via a car so i will have to carry (did this before and i do not thing i can do again) . So i am wondering based on my math if i connect 50 cells of 2.000mah 18650 batteries then i will have the same capacity like the old lead acid battery? And of course better discharge rate etc. Or there is something else that i do not understand and is not that simple as it sounds!?
Hi thumbs up on all ur videos,, very interesting,, I have a poor electronic basics skill and trying to learn enough to build a battery for a ebike project in the future from 18650 cells,, I buy bits and bobs and haven't got a clue were to put wires from and were to ,,for instance just got a small cell checker capacity like urs ,,no instructions on the pin outs of what's what ,, anywhere I will find this info please on the inter web many thanks Shane warks uk
hi there do you have a video of your lead acid battery bank
Theres a section in an old overview video... th-cam.com/video/_0wEKdta6is/w-d-xo.html
hi Adam
where do you find second hand laptop batteries. I don't seem to find any.
great post by the way
+Timothy SKing Well I work in IT so I'm able to collect any batteries before we recycle the laptops. Unfortunately however I don't get my hands on great numbers. Recently a I bought a job lot on eBay - which I'm currently processing.
I have about 100 or so LiIon batteries, and have been testing them manually. While discharging, the previous battery charged up the next battery, and with a little charging by solar panel I have tested MANY batteries now.
I had different equipment with these 18650 batteries, and many laptop packs. Bt if I look at the the end what I got, it is not very well. The ones below 1 amp hour are obviously very old or much used, I will keep those for experimenting. I think I have about 30 of those. Then between 1.1 .. 1.0 Amp hour I have really a lot batteries. The ones above 2.0 is just a few (perhaps 30 or so). But most are in 1.1..1.9 Ah, and the 2.x range does not get above 2.3 Ah. Even the Samsung ones and even unused ones. So I have the impression your batteries are overrated (or mine underrated). I use a charger of the same brand you have (I happen to have 2 of those, the lii-100).
Any how. Nice project. I will start something similar when I am done testing all batteries, so I know what I can do with it. I do think I might try something different though, which is good so other people can see how well that will work! I will parallel the battery packs when charging. so that I am absolutely sure they are balanced perfectly. And use a dc2dc controller to lower the input (solar) voltage down to 4.0 Volts. I know the dc2dc converters will loose some power on efficiency, but not needing a balancer is something I really want to see and test. The downside is you can't use the pack while charging, how ever if need be? A second dc2dc converter can boost up the parallel'ed batteries and provide the high voltage if and when needed.
All those pink Samsung cells came out of laptop batteries of which I know the full history. They were in netbooks manufactured in 2010. All of these netbooks sat for a couple of years in storage before their first use. They sadly had very little use before the netbooks were taken out of service because of broken screens, keyboards, hard drives etc. 99% of the 18650s were fine and had been through very few cycles.
I've found my LiitoKala Engineer li-300 to be pretty accurate in it's calculations benchmarking it against my own discharging arduino project. The thing that perhaps I should have mentioned is that most people on YT seem to be discharging at 1amp, and the littokala does it as only 500mA. A longer slower discharge will probably give slightly better capacity values, but equally the way I'm using them the discharge in actually use will be even lower. However in many respects the mAh figure is simply a benchmark. You just need to get the right balance in your packs. You can test it's true capacity in other ways and reduce the margin for error once the whole pack is built and running.
My pack only has outside lights attached, so they charge in the day and discharge after dark. This should hopefully ensure they give a long service life.
Having my 7s pack (and a 24 volt solar panel system charging it) allows me to only convert once as apposed to your buck and boost. It should be a little more efficient, but does add the balancing complication into the mix.
Thanks for your comments - good luck with your project.
A bit confused about the fuse wire. I was under the impression that the series connections should be a heavier gauge wire while the parallel connection uses the fuse wire.
Yes often this will be the case and I guess mine are done like that too. If you imagine that each cell has a five amp lower gauge connection. In normal operation each series group has four of these 5 amps connections to the cell series group - so this is a heavier gauge wire. So from one series group to the next there is a 20amp connection, and from each cell in a group there is 5 amp fuse protection.
It's worth noting my pack only charges at about 2.8 amp maximum and discharges a lot lower than that so high current interconnections aren't really something I need.
A metal bar sit between a battery holders, so four fuse wires goes into parallel. Is it expected?
The fuses between each group of cells is simply to protect the other cells in a group if one of the cells goes short circuit. Lets say cell two in a group of four goes short circuit. The other three cells will discharge through this short circuit from their positive to their negative. So the fuse attached to the shorted cell should blow. The other three cells will continue to work as they should now the short has been removed. Although obviously we've now got a weak group of cells that will find it hard to keep balanced with the other groups.
Friend that fuse connected on the positive of the controller for the batteries, how many amps?
+Davi Gomes Its' five amp fuse wire.
You forgot to mention/link the Lii-300 charger in the description.
Thanks - I'll add one now.
Hi Adam, nice update video.
Maybe you could also attach an Arduino with some WiFi to monitor the cells remotely, and put it on a webpage so we could also enjoy it.
Thanks - I have had a similar idea... :-)
what is the total capacity (mAh) you got for this setup ?
+Lau Weng Yew Just a little shy of 10,000 mAh at 25.9 volt nominal. That's about a quarter of a kilowatt hour :-)
it is 26.76 volts, how to charge it with solar charge controller, i am sure solar charger will not support to charge above 26 volts.
nice update dude :)
Cheers
I have once run across laptop batteries where a pair had one dead cell and one good cell. I believe each cell should be treated separately for safety reasons
you only really need a fuse per series bank as one fuse goes the hole series bank drops out
The fuse wires are for protecting each individual cell. If one of the four in series goes short circuit or needs it's neighbours to deliver lots of current to it the fuse on the damaged cell should blow. That way the battery pack keeps running but the bad cell is taken out of the equation. I might look in the future at demonstrating that. Or have I miss understood your point? Sorry if that is the case.
sorry I had forgot about the balance strip making each pack parallel my idea was to make it simpe each cell is 2ah that 8ah per parallel pack one bettery fails that means your left with 6 8ah packs and 1 6ah pack that will over charge my idea is they are in series string with a fuse on the end this way if a cell goes bad that brings the hole set of banks down to 6ah rather then mixed ah rating of a pack due to bad cell
+David Simpson I see what you mean. Yes with this method there will be one group with a lower capacity but I'd hope I'd notice before it becomes an issue.
Interesting idea you've got there though. Effectively lots of 7s1p packs strung together.
Cheers
SUPERB - I wnat to do this too :) for 3 LED lights, at 6 volt
Thanks - good luck with your project.
I often wonder how much life is being taken away using a balance board...
Love the vids.... but you have my hands... creepy!
I’ll send email back once I’m done.
I’ll send ‘em back...
@@AdamWelchUK I was trying to post a photo.
We even have moles in the same place!
XD!!!!