AWESOME talk!!! You mentioned some very valuable points, the video is long but full of great information! It’s hard to answer BMS question without explaining so much stuff first, most times my short answer for these questions is “it all depends blablabla...” cause every scenario is different. Great talk and thanks for clarifying and educating people out there =]
drain all cells down to your fav bottom voltage, like 3v, bottom balance. then just charge till first cell hits your fav top volts, like 4.15, that way imbalance is highest at start of use, and gets less as pack discharges, better protection against a cell going undervolt. 5 years on, still using same packs. thankyou jack ricard for this advice.
A passive bms is fine for a power wall. The amount of kwh's dissipated as heat is tiny compared to the kwh's flowing into and out of the pack. For electric vehicles an active bms helps optimize and minimize kwh's lost as heat, but also costs more in R & D.
Yes I agree with you about active balancers I run Diypowerwall and recently I have that issue with balancers (I have 1s balancers) that you mentioned if you have big capacity to balance down balancers don't work as good as I thought..... but if you have somehow already balanced system then they work as they should... 👍 Excellent video... 👍
Yeah people think they will balance up to advertised 6A but that is not true when getting close to same voltage im afraide. In that sense the balancing is small
Great explanation! I'd like to build an active balancer just because of the technical challenge. The algorithm is like using a syringe to syphon off liquid from overfilled buckets to transfer to emptier ones. We can do active balancing manually by connecting 2 supercapacitors in series to a high cell then physically connect to a low cell and allow them to equalise, rinse and repeat, but this way only allows a tiny amount of charge to be transferred as the voltage differentials are so small. This could be improved using a buck/boost to completely fill and empty the caps each time so a decent amount of energy can be transferred. Implementing this simple algorithm In practice is difficult because the cells are all connected in series, so have to use many relays to physically connect and disconnect the caps and ensure that only one cell is active at once for "read" or "write". A microcontroller could keep track of cell voltages and control a 4 bit to 16way multiplexer to select one of up to 16 cells and ensure only one is active at once, with another signal line to indicate direction. Switching frequency doesn't have to be high, and fairly high currents can be used. The main expense for this is the sheer number of relays or solid state relays required, and is a wiring headache!
The algorithm can also take into account the potential difference from an average measured across the pack voltage to ensure that it shows preference to the highest and lowest cells, also the balancing current could be altered depending on the amount of discharging or charging current, something that passive balancing can't do as they have fixed load resistors, meaning that under higher charge currents the highest cell will still receive a charge and therefore cause charging to be cut off to protect that cell from being overcharged, regardless of the state of charge of other cells, I know this is an issue that does not really affect new well matched cells
GREAT Talk!!! So far, I have created 56packs of 130ah each. 56/14 gives me 4 x 48v batteries - e.g. 520ah @ 48v. I top balanced each battery (14 packs in series) and then used charge controller to set the 'battery bank' to same voltage and put the new battery online. The Midnite Classic 150 controller itself is providing overcharge protection (I believe) in that max charge voltage/cut-off is settable and I've set it to 58.2v (4.16/pack) as a fail safe. Don't have low voltage protection except for 47v cutoff... e.g. potentially 1 of the packs could go way low but not sure if that's all that dangerous. I run between max charge of 54.6v (3.9v/pack) and discharge cutoff of 47v (3.36v/cell) giving me pretty good 'variance' at high/low ends. So far, I MANUALLY monitor voltages of all the packs and find a max of 0.5v difference in some batteries at low end but only < 0.1 as soon as they charge significantly up to 3.9v top end. As you said in video, the 'good packs' all seem to stay steady over the last several months of operation - no problems. I do plan to do Batrium in next year's budget - but I think I'm OK for the time being.
I ment to say - a max of 0.5v difference at low end within a battery (not between batteries) - e.g. high/low v difference within packs that make up a battery
Does anyone else make a bms system like baitrium. But cheaper? All I have seen is chineasium bms or baitrium. And diy arduino BMS. I have a 1400 cell bank to think of. And a baitrium is a bit spendy! I'd rather spend that money On more cells! Great video...
When your batttery pack start to getting old , after 500 cicles sure start needing active balacing, when the battery pack are new, small capacity and have simetrical capacity passive is OK.
Thank you aloooooot I want to built an e-bike pack using old laptop cells with different capacity and different ages . Wich balancer to use for the pack to work decent??
great vid! @9:30 so this would mean for a 14S/120P pack made up of scavenged cells of different capacities: always be careful to arrange 14cells of similar mAh into 1S (in series). but it's not a problem to then parallel many series of varying capacities, the V will drop equally, the cells with smallest capacity will be the least loaded?
All I ever see are videos of on or the other, not both Passive BMS and Active Equalizing Balancer at the same time. Doesn't make much sense that you wouldn't use one of the newer BMS for the Bluetooth, curent protection and voltage protection. With that and the use of an all directional Equalizing Balancer you get more drain from the hottest of your cells dumping to you lower cells as you charge giving you a closer balanced charge.
Have you tried active balancers from ali express. They come in different sizes 1s-14s. It basically is one board with black modules (probably bi-directional dc-dc converters). Constant balancing current is 6A with 20A peak. Thats what I have asked last night at HBPowerwall but i got brushed under carpet with cable losses - which is different kind of animal.
Yes i have. Balance AVG in those are 100ma. Max 6a with voltage diff of 2v. IF you watched My video you Saw that over time you wont get much gain. And yes you save alot more energy fixing cable losses or losses in Gear than going active balance. I balance at most 0.5 kwh per month currently... My losses are over 150kwh. Active would actually have a higher loss since it constantly balance ;) active have its area but not on a powerrwall where the aim is equal capacity from start
Ok, i have found it. It is a shame you never measured efficiency of those 1s balancers. Anyway i am thinking of using them only when cells are out of balance or turn them on for 1hr every 24hrs. Nice videos by the way, thank you.
@@ISeeYourLies Its between 80-90% (Not tested by me though) The thing with them is that they constantly balance if the voltage diff is higher then 30mV or something. That mean as soon as you apply load or charge and the cells are just slightly uneven they start counterbalance even though they arent unbalance but the IR itself is causing it. Thats one of the negative things that potentially can cause issues and use more energy than you need. Advantage is when you can set WHEN to balance and you cant do that with those rellatively dumb balancers :) They for sure have its area where you have lets say 20Ah 30Ah and 10Ah packs in series. With passive you can max use 10Ah but with active ustem you could potentially use 20Ah total capacity.. BUT in my world its better to make sure the packs are even from start. But thats not always possible. If you plan to run them for short amount of time you need a way to disconnect them and that is extra gear and you also need equipment that for instance does it in the bottom or in the top or if you are after middle balance. With that said you still need individual cell monitoring of some kind
Active blaancer is more costly. Why not just make sure your battery is ok? Or are your packs so out of balance that you need to constantly balance? Thanks
Great video very informative I wish I had the money for a batrium system is there any chance of doing a video on a more budget friendly bms system I dont mean cheap just affordable say under $100 for whole 7s or 14s system
I'm running my garage off a Tesla battery module at 24 volts the cheap BMS that I use gets hot if I'm charging too fast or drawing too fast from it can I run two of these BMS in parallel to take the heat down without using a fan
@@DIYTechRepairs hello, that's an interesting topic, any links where it is discussed more detailed? i also thought to split up my 15kWh pack into 2-3 smaller ones. it has d advantage of redundancy and possibility to switch 1 just off for maintenance/repairs without loosing all power!
Everyone Will state higher Numbers since it seems nice :) but in the real world its different. Yes you can get 95+ but dont expect that from the cheaper versions :)
I have made a native Android app for it but its not publiv yet. For now you can use Grafana with WatchmonUDPListener that I have created or use Powerflow. You can find those on my webpage
I'm still waiting for second part 🥹🙏plz
AWESOME talk!!! You mentioned some very valuable points, the video is long but full of great information! It’s hard to answer BMS question without explaining so much stuff first, most times my short answer for these questions is “it all depends blablabla...” cause every scenario is different.
Great talk and thanks for clarifying and educating people out there =]
drain all cells down to your fav bottom voltage, like 3v, bottom balance. then just charge till first cell hits your fav top volts, like 4.15, that way imbalance is highest at start of use, and gets less as pack discharges, better protection against a cell going undervolt. 5 years on, still using same packs. thankyou jack ricard for this advice.
It’s not a long video. It’s a very technical explained, I appreciate the pro and con. Thanks for lighting my understanding.
A passive bms is fine for a power wall. The amount of kwh's dissipated as heat is tiny compared to the kwh's flowing into and out of the pack. For electric vehicles an active bms helps optimize and minimize kwh's lost as heat, but also costs more in R & D.
Thank.s Bro.....
Yes..capacitors and triggering....
Great Job.
Yes I agree with you about active balancers I run Diypowerwall and recently I have that issue with balancers (I have 1s balancers) that you mentioned if you have big capacity to balance down balancers don't work as good as I thought.....
but if you have somehow already balanced system then they work as they should... 👍
Excellent video... 👍
Yeah people think they will balance up to advertised 6A but that is not true when getting close to same voltage im afraide. In that sense the balancing is small
Excellent explanation, very clear
Great explanation!
I'd like to build an active balancer just because of the technical challenge.
The algorithm is like using a syringe to syphon off liquid from overfilled buckets to transfer to emptier ones.
We can do active balancing manually by connecting 2 supercapacitors in series to a high cell then physically connect to a low cell and allow them to equalise, rinse and repeat, but this way only allows a tiny amount of charge to be transferred as the voltage differentials are so small. This could be improved using a buck/boost to completely fill and empty the caps each time so a decent amount of energy can be transferred.
Implementing this simple algorithm In practice is difficult because the cells are all connected in series, so have to use many relays to physically connect and disconnect the caps and ensure that only one cell is active at once for "read" or "write".
A microcontroller could keep track of cell voltages and control a 4 bit to 16way multiplexer to select one of up to 16 cells and ensure only one is active at once, with another signal line to indicate direction. Switching frequency doesn't have to be high, and fairly high currents can be used.
The main expense for this is the sheer number of relays or solid state relays required, and is a wiring headache!
The algorithm can also take into account the potential difference from an average measured across the pack voltage to ensure that it shows preference to the highest and lowest cells, also the balancing current could be altered depending on the amount of discharging or charging current, something that passive balancing can't do as they have fixed load resistors, meaning that under higher charge currents the highest cell will still receive a charge and therefore cause charging to be cut off to protect that cell from being overcharged, regardless of the state of charge of other cells, I know this is an issue that does not really affect new well matched cells
First! Now I can add this video to my FAQ list on discord saving me to answer it over and over.
GREAT Talk!!! So far, I have created 56packs of 130ah each. 56/14 gives me 4 x 48v batteries - e.g. 520ah @ 48v. I top balanced each battery (14 packs in series) and then used charge controller to set the 'battery bank' to same voltage and put the new battery online. The Midnite Classic 150 controller itself is providing overcharge protection (I believe) in that max charge voltage/cut-off is settable and I've set it to 58.2v (4.16/pack) as a fail safe. Don't have low voltage protection except for 47v cutoff... e.g. potentially 1 of the packs could go way low but not sure if that's all that dangerous. I run between max charge of 54.6v (3.9v/pack) and discharge cutoff of 47v (3.36v/cell) giving me pretty good 'variance' at high/low ends. So far, I MANUALLY monitor voltages of all the packs and find a max of 0.5v difference in some batteries at low end but only < 0.1 as soon as they charge significantly up to 3.9v top end. As you said in video, the 'good packs' all seem to stay steady over the last several months of operation - no problems. I do plan to do Batrium in next year's budget - but I think I'm OK for the time being.
I ment to say - a max of 0.5v difference at low end within a battery (not between batteries) - e.g. high/low v difference within packs that make up a battery
Very good talk. Knowledgeable
Does anyone else make a bms system like baitrium. But cheaper? All I have seen is chineasium bms or baitrium. And diy arduino BMS. I have a 1400 cell bank to think of. And a baitrium is a bit spendy! I'd rather spend that money On more cells! Great video...
When your batttery pack start to getting old , after 500 cicles sure start needing active balacing, when the battery pack are new, small capacity and have simetrical capacity passive is OK.
Not needed. I have packs doing above 1000 cycles Still running normal passive :)
Loved it! I agree 100% great video thanks a lot.
Awesome Video Man!!!!👍
Thank you aloooooot
I want to built an e-bike pack using old laptop cells with different capacity and different ages . Wich balancer to use for the pack to work decent??
U are wonderfull man.thank you for video.i learned it myself with experience but thanks
Thank you! I always learn good stuff from you!
Excellent ! You really stated this well....
very informative! Thank you!!
active balancing nicely explained - thanks
great vid! @9:30 so this would mean for a 14S/120P pack made up of scavenged cells of different capacities: always be careful to arrange 14cells of similar mAh into 1S (in series). but it's not a problem to then parallel many series of varying capacities, the V will drop equally, the cells with smallest capacity will be the least loaded?
All I ever see are videos of on or the other, not both Passive BMS and Active Equalizing Balancer at the same time. Doesn't make much sense that you wouldn't use one of the newer BMS for the Bluetooth, curent protection and voltage protection. With that and the use of an all directional Equalizing Balancer you get more drain from the hottest of your cells dumping to you lower cells as you charge giving you a closer balanced charge.
Have you tried active balancers from ali express. They come in different sizes 1s-14s. It basically is one board with black modules (probably bi-directional dc-dc converters). Constant balancing current is 6A with 20A peak. Thats what I have asked last night at HBPowerwall but i got brushed under carpet with cable losses - which is different kind of animal.
Yes i have. Balance AVG in those are 100ma. Max 6a with voltage diff of 2v. IF you watched My video you Saw that over time you wont get much gain. And yes you save alot more energy fixing cable losses or losses in Gear than going active balance. I balance at most 0.5 kwh per month currently... My losses are over 150kwh. Active would actually have a higher loss since it constantly balance ;) active have its area but not on a powerrwall where the aim is equal capacity from start
Note that the goal is not to have to balance. And we try only to balance when we have excess energy
Could you provide link to the video where you review them??
Ok, i have found it. It is a shame you never measured efficiency of those 1s balancers. Anyway i am thinking of using them only when cells are out of balance or turn them on for 1hr every 24hrs. Nice videos by the way, thank you.
@@ISeeYourLies Its between 80-90% (Not tested by me though) The thing with them is that they constantly balance if the voltage diff is higher then 30mV or something. That mean as soon as you apply load or charge and the cells are just slightly uneven they start counterbalance even though they arent unbalance but the IR itself is causing it. Thats one of the negative things that potentially can cause issues and use more energy than you need. Advantage is when you can set WHEN to balance and you cant do that with those rellatively dumb balancers :) They for sure have its area where you have lets say 20Ah 30Ah and 10Ah packs in series. With passive you can max use 10Ah but with active ustem you could potentially use 20Ah total capacity.. BUT in my world its better to make sure the packs are even from start. But thats not always possible. If you plan to run them for short amount of time you need a way to disconnect them and that is extra gear and you also need equipment that for instance does it in the bottom or in the top or if you are after middle balance. With that said you still need individual cell monitoring of some kind
Was hoping to watch part 2. Cannot find.
Its not done yet :)
thank you. nice video
except money.. I will choice active-balance. :) and thanks for making this video.
Active blaancer is more costly. Why not just make sure your battery is ok? Or are your packs so out of balance that you need to constantly balance? Thanks
Can you compare the time required for balancing cells in both ACTIVE and PASSIVE balancing cases
I dont see the benefit of that
It all just depends on balancing current and can easily be calculated :)
Great video very informative I wish I had the money for a batrium system is there any chance of doing a video on a more budget friendly bms system I dont mean cheap just affordable say under $100 for whole 7s or 14s system
There are. But as always money vs what you get. Check out my smart bms review that is an cheaper variant
Great video.
I'm running my garage off a Tesla battery module at 24 volts the cheap BMS that I use gets hot if I'm charging too fast or drawing too fast from it can I run two of these BMS in parallel to take the heat down without using a fan
Potentially yes but its better with 1 bigger. Paralleling can cause other strange issues where they work against each other.
@@DIYTechRepairs hello, that's an interesting topic, any links where it is discussed more detailed? i also thought to split up my 15kWh pack into 2-3 smaller ones. it has d advantage of redundancy and possibility to switch 1 just off for maintenance/repairs without loosing all power!
Very well explained. Cooooool pencil..
fill a cap from one cell .. and empty it into another
Where did you get 10 to 20% loss, I've found active balancers with efficiency in the high 90s, you don't go into the various algorithms
Everyone Will state higher Numbers since it seems nice :) but in the real world its different. Yes you can get 95+ but dont expect that from the cheaper versions :)
@@DIYTechRepairs agreed so my advice would be not to use cheap active balancers in the same way I wouldn't use a cheap BMS
@12:00 -> 1+2+2 = 6 ??
1+3+2
Do you if there is anyway of monitoring batrium BMS with android phone ?
I have made a native Android app for it but its not publiv yet. For now you can use Grafana with WatchmonUDPListener that I have created or use Powerflow. You can find those on my webpage
@@DIYTechRepairs that's all above my pay grade. Do you know when batrium will do an app ?
@@GarryL277 is free software above your paygrade? How can you afford batrium then ? :)
Ha you misunderstood me in Australia we say that when we don't know how to do something
@@GarryL277 ahh :) the native app is just A proof of concept. It only works of you are One same wifi Network. Timeframe unknown.
Second!! Great Topic!!
njfulwider5 so much POWEEEEEERRR