diy solar

diy solar

battery balancing

RLloyd said:
bank that was built using 8 3.2v lithium cells in series to make 24v and put into parallel circuit with another 8 3.2v cells
Click to expand...
No. Each battery requires its own BMS.

If you wanted to make a 24v battery from 16 cells, you could make a 2P8S battery bank.
This would allow you to use a single 8S BMS (you wanted to use a single BMS, right?)

Did i answer what I think you were asking?
 
Yes thank you. I should have done more research before I ordered. I got a felling that I maybe be selling a few things I should have never ordered.
 
RLloyd said:
Do you have a bms in mind for someone on a budget?
Click to expand...
Everybody is on a budget! Can you be more specific on what you are looking for in a BMS?
8S? How many amps will you need it to handle (charge or load, whichever is greater plus 25 to 50% depending
on who makes it, aka who as exaggerated specs).

Here is a good thread:
diysolarforum.com

2p8s or 8s2p

Hello. I hope y’all are having a good day/night. I was wondering in configuring a 24v system with 16 cells 3.2v 100ah which is better configuration, 2p8s or 8s2p? I think I know 2p8s is better but I do not know why? Please let me know what you know:) And also if you still wanted to upgrade...
diysolarforum.com diysolarforum.com
 
I am looking to balance all 16 cells individually. I have already purchased low voltage cut off and high voltage cut off I have a charge controller Do I need something else to manage these cells and make them last? I know that I need temp control.
 
RLloyd said:
Do I need something else to manage these cells and make them last?
Click to expand...
You NEED a BMS.
Low voltage cut off is for overall battery voltage and does not look at individual cells. Same for high voltage but that should be managed with charge settings and a BMS as a necessary safety device for cell level monitoring.
 
RLloyd said:
Will I need 2 bms's to monitor all 16 cells?
Click to expand...
Yes if you make 2x 8S batteries and connect them in parallel.

If you make a 2P8S battery, your 8S BMS monitors battery pairs (the 2P part).

I have a 2P4S battery with 8x 206ah cells. Works great. I made an effort to make the battery
pairs have similar characteristics (weakest with strongest) so that the pair capacities were as uniform as possible.

From the other thread Steve_S is NOT a fan of multiple cells in parallel. He likes to monitor each individual
cell and thats a good strategy but it comes at a cost (a second BMS for your scenario). If you are on a budget and want to try an 8S BMS that you may already own, 2P8S is a way to give it a go. You can always get a 2nd BMS and make 2 separate 8S batteries.

And as it appears you have discovered, hi amperage balancers. That is a new concept that people are starting to work with. I suspect it will become much more popular as its easier than a lot of other strategies and not overly expensive.
 
I have purchased 1 40 amp charge controller and would like to get another at a lower price that would be a good one as well I paid $200 for Epever MPPT Solar Charge Controller 12V/24V Solar Regulator 150V 40A/ I would like to give another type a try. I would also like to get a good 40a bms as well what would you recommend. I have 6 350w 72 cell panels and have 8 100 watt panels I would appreciate any advice
 
RLloyd said:
I would also like to get a good 40a bms as well what would you recommend.
Click to expand...
Your BMS should be a bit bigger than you max charge or load current. If you are planning on using an inverter that is bigger than 40a (40 x 12.8 = 512w) then size for that, plus "some" (a little for a top brand, a lot for a cheapie).

RLloyd said:
I would like to give another type a try.
Click to expand...
Are you looking to use this in conjunction with your EPEver or ??
You have a lot of panels!
RLloyd said:
I have 6 350w 72 cell panels and have 8 100 watt panels I would appreciate any advice
Click to expand...
You should size your next SCC based on how you intend to use it and the specs of
these panels and how you can wire your array. Staying below the SCC's max input voltage
with the Voc's (summed for series x 1.12 for temperature voltage change) is the key.

If you need some help on how to setup arrays and plan for voltage limits in an SCC please ask.
You'll need to provide the Voc numbers for your 2 types of panels.
 
6 of these at 350 watt per panel they are 47voc the others 8 panels are 100 watt and voc is not listed they are 18 volts
 
I am thinking about buying 2 of these bms and installing in parallel 24v It ask to pick between life common, life separate and lincm common I do not understand what they mean. I have lifepo4 prismatic cells 3.2
 
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