Do the wires have to be the same length on pos and neg on each batery? Do fuses add to the length? Or is all pos same and all neg but pos and neg can be diff lengths on bus?
Sir could be possible if I want to make a parallel (12 v, 100ah x2) then I series it with 12v 200ah...in other term 12v 100ahx2 + 12v 200ah...thank in advance for feedback...need feedback...
If you have a 12V system, then you need to wire them all in parallel. If you have a 24V system: you can only use the 2x 12V 100AH in series. your single 12V 200Ah will be left out of the system.
i had cable wires shoter and was draing battery more then the other. I have two 24 volt 200ah batterys conneted in series to make 54 volts i conneted it 4 hours ago I have to go turn of everthing off and paralele the batterys to bring them both the same volts now as one is 78% and the other 100% glad i so your video explained a lot i did not know thank you.
hi thanks for your videos. I have 52 AGM 12V and 40 Ah batteries. I would like to create a photovoltaic storage unit (I know they are not indicated but I want to try). What type of series/parallel connection should I make to maximize Wh and get 48V total?
ive watched at least 15vids just shoeing me how 2 do it i no paralel means not wireing thrm like a worm but do u use the opasite side of yhr negative to the oppadsite side of the negative or can u use the same size and am here like 15bids or 20 vids later i hope this shows me better it lools ok
What is the best configuration to connect three lead acid batteries wired in parallel to the charging and load wires without a buss bar available? Should the charging and load wires be connected to the same terminals?
Yes, all to the same terminals. Main positive on battery 1 and main negative on battery 2. Max 3 connections per battery terminal. Otherwise -> busbars.
I intend on taking several 20v 1.5 ah 18650 powered tool batteries and creating a larger more capable battery. My only question is would it be better to make 5 banks of 4v and run that in series , or 5 20v banks
@@cleversolarpower the wire and all other components will be oversized regardless. I was wondering if either way is advantageous with regards to capacity longevity and power delivery
I have 300 watts on panels coming in to a 400 watt charge controller. Then from there to a 12v battery with 35AH. Then to a 2000Watt inverter. Can you help me determine how I can improve this or if I’m doing this wrong.
I have 4 x 6v AGMVRLA 6v 75lbs batteries in my RV. They are plugged in, in the combination setup you have shown. I use them to off set pole power as our RV needs more power than the RV park gives us. I want to set up a solar trickle charger over the winter to keep them charged, would I have to change from a combination setup or can I just plug in some solar panels to them with clamps and they will charge them all.
Every battery is fused and goes to the busbar. This is for current sharing reasons. Also if one battery fails, the rest will dump their short circuit current into it, that's why you need a fuse.
I wish to add 4 high capacity batteries to my current setup of 4 batteries, is it recommended? If so, how to connect them? I.e. first I connect 4 batteries in parallel and then connect to another circuit? Thanks
1:23 that is not the way to size a Charge Controller. A charge controller amps depends upon the Solar Array Current at Maximum Power Or Imp and depending how many panels are connected in Parallel.
No, you are wrong. The current of the charge controller is determined by the charging current to the battery, not the input current from the solar panels.
@@giovanninongbri2250 Take your solar panel power and divide by battery voltage, then you have your charging current to the battery. 600W/12V=50A -> 50A charge controller. Then you have to calculate the input voltage, because there is a limit on it. max input voltage = Voc*panels in series * 1.25. If a panel has 22V Voc, then: 22V*3panels in series*1.25=82.5V -> charge controller with 100V max input voltage is ok. Hope this helps.
@@cleversolarpower so you're telling me that the controller makes its own current to charge a battery? the solar array current charges the battery so if you have a 36 cells Solar panel which is considered 12Volts or having a voltage maximum Vmp rating of 17Volts and a maximum current or Imp rating of 8 amps and suppose you have three panels connected them in parallel the total amps would add up to 24 amps, whereby the voltage stays the same as 17Volts, So the current coming from the solar array to the controller will be 24 amps so choose a controller size of 24 amps x 1.25 = 30amps and if you have a single 12V Lead acid battery then select a controller of 12Volts. Hope this helps , I'm an experience in the solar industry with installations and sizing so I believe I'm qualified to share my opinion and the sizing of a controller.
@@giovanninongbri2250 A charge controller takes the total input power from the solar panels, not only the current because power=voltage*current. If you have a PWM, then you should do it the way you described. If you have an MPPT, then you need to connect as many panels in series to the max allowable input voltage of the charge controller. Remember, it is total input power that matters, and not current.
Hi, with the c rating when connecting a inverter to draw 240 volts can a microwave capacitor be used to eliminate this issue of having more batteries in parallel? If possible is there a specific way to wiring. I have see capacitors in parallel being used in some setups on utube this way for the initial draw.
A capacitor bank will help with reducing the startup current. Microwave is an inductive load so a capacitor bank will help reduce this. I haven't done this before, so I don't have any personal information to share.
Great vid! Easy to understand. Q… Can I connect 2 12v 50Ah Li-ion batts in Series/Parallel (24v 100Ah total) or is there a min # of batts (ex. 4 or more)? Pros and Cons please 😁
@cleversolarpower thabk you for reply. I meant that I have 1 set of batteries. Battery 1 12v 280 ah and battery 2 12v 280 in series to make a 24v of 560 ah & a separate Battery 3 12v 100 ah and battery 4 12v 100 ah in series to make 24v 200 ah. Could I now parralell the battery 1 and battery 2 to battery 3 and battery 4 (battery 1 and 2 became 1 and battery 3 and 4 became another )
Hi sir, i have 4 × 200watts solar panels, and 20A charger controller, 1500watts inverter plus 3× 24 v batteries. Any recommended from you. What size cable i need? Thanks sir
I have 4x100Ah Lithium batteries that I want to keep in parallel @ 12v and want to connect a 3000watt inverter to. I'm aware of the cable size requirement with a safety margin being around 312amps and 0000B&S or 120mm cable seems to be what's required when considering what the inverter can draw in current. My confusion is 'if' a busbar is used does each battery connected to the busbar have to have 0000B&S cable interconnects or will the 0000B&S cable only be required as the connection cable at the end of the busbar to loads? It seems to me that each battery will only supply one quarter each of the max current so cable size from each battery to the busbar can be reduced accordingly. Am I wrong?
If it's lithium and they have a BMS inside, you make two battery banks. One 110ah 12v and one 100ah 12v. Let both batteries go to a busbar. Every battery bank (2) needs to be fused separately.
Hey Nick. I am still confused after all my research. I Recently purchased two 24v 100aH LifeP04 batteries. I plan to connect them in parallel to get longer lasting power. I am having difficulty determining what cable size I will need for the parallel connections between batteries and from the batteries to my 24v 3k watt Growatt all in one Inverter. Thank you for any insight.
Checkout one of my latest videos about current sharing. To make it easy, just use the same cable that you would run up to the inverter for interconnecting batteries. For a complicated answer, checkout my video about current sharing.
Could I connect 2 12v 280 ah batteries I have in series (24v now) to two other batteries of 12v 100ah that I have in series (24v now) IN PARALLEL? 2 separate series connected batteries to be connected in PARALLEL?
@@cleversolarpower thabk you for reply. I meant that I have 1 set of batteries. Battery 1 12v 280 ah and battery 2 12v 280 in series to make a 24v of 560 ah & a separate Battery 3 12v 100 ah and battery 4 12v 100 ah in series to make 24v 200 ah. Could I now parralell the battery 1 and battery 2 to battery 3 and battery 4 (battery 1 and 2 became 1 and battery 3 and 4 became another )
If I connect 2 12v battery in series. Will it increase the watt hour? Meaning more Capacity? For example, I have 2 12v 280ah battery which has 3584Wh. If I connect 2 in series it will has 24v and 7168 wh. So I double my capacity?
No. If you connect in series, only your voltage will be doubled up. If you want to double your wattage, you need to connect them in Parallel, but the voltage will stay the same. If you want to double the voltage and wattage at the same time, you need 4 batteries with same spec, or just buy new batteries.
@@reinaldodevara I'm still confused. Let say we connect 2 12v 100ah battery. We will have 24v 100 ah battery which is 2400 watt hr capacity. But a single 12v 100ah battery will have only about 1200 watt hr capacity. So we double the capacity?
@@TienTran-bi1jv oh I am sorry, if it is in wattage, it means power. If the voltage doubled, yes of course the wattage will be doubled too as the formula for wattage is voltage x amperage. But the capacity (Ah) will still the same.
Increasing the voltage will reduce the current draw from the battery. Less current draw= slower discharge rates = longer lifespan. Check my video about C rate.
WoW never heard about c-rate, and believe me, no e bike owner mention it. Wel i have 4 lead acid each 7 amp. Is it wise to make for mij ebike a c - rate configurations. The controller can handle 12-24-26 volt. Just have them now series it works
Some lithium batteries shouldn’t be wired in series? Is there a way to know when it’s not okay? Im specifically looking to wire 24v Flex tool batteries in series and parallel to double voltage and capacity.
It should be mentioned on the product datasheet. The reason is that some BMS'es are not made for the increase in voltage like 48V. However, most batteries can do that now, it was mainly a problem of the past.
You can get it through the link in the description which brings you to Amazon. You can also get the pdf version on my website. Or your local Amazon website.
Do you actually need one? With 4 batteries this seems less likely. Measure the voltage of each battery. If needed parallel them or charge individually to reduce voltage fluctuations.
20W*12h=240Wh. If you have a 12V battery, then: 240Wh/12V=20Ah@12V. If you are using lead-acid, then multiply this by 2 and if you use LiFePO4, then multiply by 1.2 Hope this helps.
@@BlackPearl5077 Try to read again and do the math yourself. Once you understand you can replicate on all your appliances. Or use my calculator on my website.
If you connect two batteries of the same voltage but different capacities in series, you will get the correct voltage, but the battery with the lower capacity will be overworked as it will discharge faster than the larger one. This can lead to reduced battery life and potential damage to the batteries.
Ive seen a lot of these videos and each one has a different way to wire in parallel and the type of inline fuse to use. I just went to an electrician site and it was different than this one.
If I wire 212 V lithium ion batteries that are 100 amp hours each and have a watt rating of 3800 WATTHOURS hours I know the voltage will double the amperage will stay the same but what happens to the WATTHOURS WILL the WATTHOURS double or will they stay the same? Thank you for anyone who can help me with this ❤️❤️🇺🇸
Not good engineering practice to connect low impedance batteries in parallel - large circulating currents may result causing potential fire / explosion.
Your batteties need to be the same make, don't mix them. Especially if they are different. Each manufacturer has their own bms at different charge/ discharge rates and volts.
🎁Get 7 FREE diagrams to kickstart your Off-Grid journey! View and get them here: cleversolarpower.com
How to connect 4 batteries, two in parallel and two in sirres? Thanks
Perfect diagrams. Exactly what I needed to put my solar batteries back in (I remove them from my cabin in fall so they don't freeze over the winter).
This is one of the best vids ive seen thanks ✌️
Hi received your off-grid solar power simplified book. I thank you.
Parallel sums the amps together. (“Parallel” has a’s in the word to help you remember “amps”. “Series” does not.)
Good trick.
Do the wires have to be the same length on pos and neg on each batery? Do fuses add to the length? Or is all pos same and all neg but pos and neg can be diff lengths on bus?
Hi, where would you put fuses on the combination connection? The 24v paraserie
Good explained
Sir could be possible if I want to make a parallel (12 v, 100ah x2) then I series it with 12v 200ah...in other term 12v 100ahx2 + 12v 200ah...thank in advance for feedback...need feedback...
If you have a 12V system, then you need to wire them all in parallel. If you have a 24V system: you can only use the 2x 12V 100AH in series. your single 12V 200Ah will be left out of the system.
i had cable wires shoter and was draing battery more then the other. I have two 24 volt 200ah batterys conneted in series to make 54 volts i conneted it 4 hours ago
I have to go turn of everthing off and paralele the batterys to bring them both the same volts now as one is 78% and the other 100% glad i so your video explained a lot i did not know thank you.
Thanks man for the teaching 🤝
hi thanks for your videos. I have 52 AGM 12V and 40 Ah batteries. I would like to create a photovoltaic storage unit (I know they are not indicated but I want to try). What type of series/parallel connection should I make to maximize Wh and get 48V total?
Very informative. Thanks
Thanks for the information
Very useful. Thank you!
ive watched at least 15vids just shoeing me how 2 do it i no paralel means not wireing thrm like a worm but do u use the opasite side of yhr negative to the oppadsite side of the negative or can u use the same size and am here like 15bids or 20 vids later i hope this shows me better it lools ok
Very useful & well-explained video. Thank you ! (=
Very clear. Thank you.
Best explanation
What is the best configuration to connect three lead acid batteries wired in parallel to the charging and load wires without a buss bar available? Should the charging and load wires be connected to the same terminals?
Yes, all to the same terminals. Main positive on battery 1 and main negative on battery 2. Max 3 connections per battery terminal. Otherwise -> busbars.
I intend on taking several 20v 1.5 ah 18650 powered tool batteries and creating a larger more capable battery. My only question is would it be better to make 5 banks of 4v and run that in series , or 5 20v banks
I would increase voltage as it will mean less current thus less thick wire.
@@cleversolarpower the wire and all other components will be oversized regardless. I was wondering if either way is advantageous with regards to capacity longevity and power delivery
I have 300 watts on panels coming in to a 400 watt charge controller. Then from there to a 12v battery with 35AH. Then to a 2000Watt inverter. Can you help me determine how I can improve this or if I’m doing this wrong.
Your battery is too small. Check my video about how many batteries for a 3000W inverter. It's my most watched one.
I have 4 x 6v AGMVRLA 6v 75lbs batteries in my RV. They are plugged in, in the combination setup you have shown. I use them to off set pole power as our RV needs more power than the RV park gives us. I want to set up a solar trickle charger over the winter to keep them charged, would I have to change from a combination setup or can I just plug in some solar panels to them with clamps and they will charge them all.
I assume they are wired as 24V? Then having a charger attached to them (positive to batt 1 and negative to batt 4) will do the job.
4:20 i dont understand whats the diff hrere in wiring , why is left marked wrong and right marjed as correct?
Every battery is fused and goes to the busbar. This is for current sharing reasons. Also if one battery fails, the rest will dump their short circuit current into it, that's why you need a fuse.
I wish to add 4 high capacity batteries to my current setup of 4 batteries, is it recommended?
If so, how to connect them? I.e. first I connect 4 batteries in parallel and then connect to another circuit? Thanks
I recommend a max of 5 batteries in parallel. So you need two sets of 4 batteries in parallel. Each set goes to the main busbar.
1:23 that is not the way to size a Charge Controller. A charge controller amps depends upon the Solar Array Current at Maximum Power Or Imp and depending how many panels are connected in Parallel.
No, you are wrong. The current of the charge controller is determined by the charging current to the battery, not the input current from the solar panels.
@@cleversolarpower if so then why do we connect Solar panels to a controller in the first place??
@@giovanninongbri2250 Take your solar panel power and divide by battery voltage, then you have your charging current to the battery. 600W/12V=50A -> 50A charge controller. Then you have to calculate the input voltage, because there is a limit on it. max input voltage = Voc*panels in series * 1.25. If a panel has 22V Voc, then: 22V*3panels in series*1.25=82.5V -> charge controller with 100V max input voltage is ok. Hope this helps.
@@cleversolarpower so you're telling me that the controller makes its own current to charge a battery? the solar array current charges the battery so if you have a 36 cells Solar panel which is considered 12Volts or having a voltage maximum Vmp rating of 17Volts and a maximum current or Imp rating of 8 amps and suppose you have three panels connected them in parallel the total amps would add up to 24 amps, whereby the voltage stays the same as 17Volts, So the current coming from the solar array to the controller will be 24 amps so choose a controller size of 24 amps x 1.25 = 30amps and if you have a single 12V Lead acid battery then select a controller of 12Volts. Hope this helps , I'm an experience in the solar industry with installations and sizing so I believe I'm qualified to share my opinion and the sizing of a controller.
@@giovanninongbri2250 A charge controller takes the total input power from the solar panels, not only the current because power=voltage*current. If you have a PWM, then you should do it the way you described. If you have an MPPT, then you need to connect as many panels in series to the max allowable input voltage of the charge controller. Remember, it is total input power that matters, and not current.
Hi, with the c rating when connecting a inverter to draw 240 volts can a microwave capacitor be used to eliminate this issue of having more batteries in parallel?
If possible is there a specific way to wiring.
I have see capacitors in parallel being used in some setups on utube this way for the initial draw.
A capacitor bank will help with reducing the startup current. Microwave is an inductive load so a capacitor bank will help reduce this. I haven't done this before, so I don't have any personal information to share.
Great vid! Easy to understand. Q… Can I connect 2 12v 50Ah Li-ion batts in Series/Parallel (24v 100Ah total) or is there a min # of batts (ex. 4 or more)? Pros and Cons please 😁
Answered your email 😉
@cleversolarpower thabk you for reply.
I meant that I have 1 set of batteries. Battery 1 12v 280 ah and battery 2 12v 280 in series to make a 24v of 560 ah
& a separate
Battery 3 12v 100 ah and battery 4 12v 100 ah in series to make 24v 200 ah.
Could I now parralell the battery 1 and battery 2 to battery 3 and battery 4 (battery 1 and 2 became 1 and battery 3 and 4 became another )
Hi sir, i have 4 × 200watts solar panels, and 20A charger controller, 1500watts inverter plus 3× 24 v batteries. Any recommended from you.
What size cable i need?
Thanks sir
You can checkout my video about selecting wire and fuse sizes.
What will happen if we connect 3 200A 12 v and 100A 12v connected on series all gel what will happen
I have 4x100Ah Lithium batteries that I want to keep in parallel @ 12v and want to connect a 3000watt inverter to. I'm aware of the cable size requirement with a safety margin being around 312amps and 0000B&S or 120mm cable seems to be what's required when considering what the inverter can draw in current. My confusion is 'if' a busbar is used does each battery connected to the busbar have to have 0000B&S cable interconnects or will the 0000B&S cable only be required as the connection cable at the end of the busbar to loads? It seems to me that each battery will only supply one quarter each of the max current so cable size from each battery to the busbar can be reduced accordingly. Am I wrong?
That is correct. Add a 150% factor to it as i have explained in the video.
Good day sir can i connect 2units 55ah 12v and 1unit 100ah 12v battery in parallel connection with the same brand of battery?
If it's lithium and they have a BMS inside, you make two battery banks. One 110ah 12v and one 100ah 12v. Let both batteries go to a busbar. Every battery bank (2) needs to be fused separately.
Hey Nick. I am still confused after all my research. I Recently purchased two 24v 100aH LifeP04 batteries. I plan to connect them in parallel to get longer lasting power. I am having difficulty determining what cable size I will need for the parallel connections between batteries and from the batteries to my 24v 3k watt Growatt all in one Inverter. Thank you for any insight.
Checkout one of my latest videos about current sharing. To make it easy, just use the same cable that you would run up to the inverter for interconnecting batteries. For a complicated answer, checkout my video about current sharing.
4A / mm^2
@@cleversolarpowerThank you!
Good info.
Could I connect 2 12v 280 ah batteries I have in series (24v now) to two other batteries of 12v 100ah that I have in series (24v now) IN PARALLEL?
2 separate series connected batteries to be connected in PARALLEL?
Yes, battery 1 24v 280ah seperate and battery 2 24v 100ah seperate to make one big 24v 380ah battery. Every battery set needs to be fused.
@@cleversolarpower thabk you for reply.
I meant that I have 1 set of batteries. Battery 1 12v 280 ah and battery 2 12v 280 in series to make a 24v of 560 ah
& a separate
Battery 3 12v 100 ah and battery 4 12v 100 ah in series to make 24v 200 ah.
Could I now parralell the battery 1 and battery 2 to battery 3 and battery 4 (battery 1 and 2 became 1 and battery 3 and 4 became another )
Is it good if I have a 24V battery that is 100Ah with a 600w/24v inverter? The difference is 5 amps, is that bad?
Not sure what you mean by difference. Send me an email because I don't see replies.
@@cleversolarpower okay
What is the meaning of 0.2c and how did you do your calculation
Check my video about C rate to learn more about it.
If I connect 2 12v battery in series. Will it increase the watt hour? Meaning more Capacity? For example, I have 2 12v 280ah battery which has 3584Wh. If I connect 2 in series it will has 24v and 7168 wh. So I double my capacity?
No. If you connect in series, only your voltage will be doubled up. If you want to double your wattage, you need to connect them in Parallel, but the voltage will stay the same. If you want to double the voltage and wattage at the same time, you need 4 batteries with same spec, or just buy new batteries.
@@reinaldodevara I'm still confused. Let say we connect 2 12v 100ah battery. We will have 24v 100 ah battery which is 2400 watt hr capacity. But a single 12v 100ah battery will have only about 1200 watt hr capacity. So we double the capacity?
@@TienTran-bi1jv oh I am sorry, if it is in wattage, it means power. If the voltage doubled, yes of course the wattage will be doubled too as the formula for wattage is voltage x amperage. But the capacity (Ah) will still the same.
If an appliance draws a certain amount of energy, how does a change to voltage increase the battery life?
Increasing the voltage will reduce the current draw from the battery. Less current draw= slower discharge rates = longer lifespan. Check my video about C rate.
WoW never heard about c-rate, and believe me, no e bike owner mention it. Wel i have 4 lead acid each 7 amp. Is it wise to make for mij ebike a c - rate configurations. The controller can handle 12-24-26 volt. Just have them now series it works
4 12V batteries in series will give you 48V at 7Ah. With a 0.2C rate you should only draw 1.4A*48V=67W
Thank you sir
Some lithium batteries shouldn’t be wired in series? Is there a way to know when it’s not okay? Im specifically looking to wire 24v Flex tool batteries in series and parallel to double voltage and capacity.
It should be mentioned on the product datasheet. The reason is that some BMS'es are not made for the increase in voltage like 48V. However, most batteries can do that now, it was mainly a problem of the past.
Awesome! Thanks!
Très bien expliqué merci 👍
Thank you for subscribing!
Can we connect 100 Ah with 150 AH in parallel ?
Yes, if they are the same voltage.
How can I get your book?
You can get it through the link in the description which brings you to Amazon. You can also get the pdf version on my website. Or your local Amazon website.
good explanation
How Can we connect equalizer 24v for 4 battery in connected 24v ?
Do you actually need one? With 4 batteries this seems less likely. Measure the voltage of each battery. If needed parallel them or charge individually to reduce voltage fluctuations.
Can you feed a single 12v battery from a 24v solar array?
Yes, it's not going to be efficient if you have a PWM. But no problem with an MPPT.
@@cleversolarpower Two 12V peltiers how do i connect them directly to 24V solar panel?
Sir plz advised me offgrid solar inverter or hybrid solar inverter
I will make a video about it soon.
Thanks
May i ask.
If i use 20 w led lights i want to use 12 hours a day how many Ah batteries i need?
20W*12h=240Wh. If you have a 12V battery, then: 240Wh/12V=20Ah@12V. If you are using lead-acid, then multiply this by 2 and if you use LiFePO4, then multiply by 1.2 Hope this helps.
@@cleversolarpower not really understands 😅
@@BlackPearl5077 Try to read again and do the math yourself. Once you understand you can replicate on all your appliances. Or use my calculator on my website.
can i series 2 different AH battery with same voltage?
If you connect two batteries of the same voltage but different capacities in series, you will get the correct voltage, but the battery with the lower capacity will be overworked as it will discharge faster than the larger one. This can lead to reduced battery life and potential damage to the batteries.
@@cleversolarpower thanks so much sir for info
If l connected different c-rayt what happens
No problem. C-rate does not have an effect.
Ive seen a lot of these videos and each one has a different way to wire in parallel and the type of inline fuse to use. I just went to an electrician site and it was different than this one.
That's because there are different methods to wire them.
Ben jij nederlands ?
Ja
If I wire 212 V lithium ion batteries that are 100 amp hours each and have a watt rating of 3800 WATTHOURS hours I know the voltage will double the amperage will stay the same but what happens to the WATTHOURS
WILL the WATTHOURS double or will they stay the same?
Thank you for anyone who can help me with this ❤️❤️🇺🇸
What do you mean with water? Send me an email because we need to get to the bottom of this well 😄
My apologies I was talking not typing😞
It made water out of WATTHOURS?
It doesn't matter whether you wire them up in series or in parallel the Watt-hours just add up.
Without a pos and negative in video it really doesn't tell the average guy nothing
This video is packed with positive and negatives, i recommend you watch it again 😉
@@cleversolarpower some of these posts are shocking. It seems to be the current trend. Watt..?? just ignore me, I'm a bit flat..
Not good engineering practice to connect low impedance batteries in parallel - large circulating currents may result causing potential fire / explosion.
You should only connect in parallel when they are at the same voltage (state of charge).
John 3;16
Your batteties need to be the same make, don't mix them. Especially if they are different. Each manufacturer has their own bms at different charge/ discharge rates and volts.
talks to much and says very little