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Making three 200ah batteries to parallel into 600ah battery bank

If your running these in your RV I assume your running a 12v system.

This would mean 4 of those in series. (4s)

If you wanted a bigger battery you could wire 2 in parallel and then 4 of those sets in series (2p4s)

Again assuming 12v you want a 4s Lifepo4 BMS.

Then decide on maximum load you need and choose one that exceeds this.

I run a 60amp one in my RV setup. But I only run fridges/ lights / stereo etc and small inverter.

The brand Craig mentioned above is Daly and are popular and have a reputation for reliability.

Best of luck.

Jimmy
 
Thanks guys, 12v is what I need. I have a fairly small battery box that only fits 4@CR260 LA batteries now so I am thinking I series 4 cells each to make 3 each 12.8v batteries. Then Parallel them into 600AH The spec says those batteries are SINOPOLY model SP-LFT200AHA I would like to be able to draw up to a max of 300amps from the pack, which looks like 1/2 of their capability, as they are rated 1C which should allow 600 amps continuous draw if I understand this part.

We currently pull about 250AH from our LA batteries in 24 hours (measured by a Trimetric, soon to be a Victron BMV) I am hoping to get up to 3 days of dry camping from them during minimal solar energy production.

I am still a bit fuzzy on the BMS as Craig said to put them in parallel first. I am looking at 12 cells of 3.2v 200AH.

Is he saying to make 4 batteries @ 3.2v using 3 cells each paralleled connected, and then put those 4 resultant 3.2v "batteries" into a series to make the the 12.8 @ 600ah? How does that help? I am still dcyphering the greek..

I had assumed I would make 3 batteries @ 12.8v (4 cells) then parallel them together. Kind of like buying 12v car batteries and paralleling them together for the higher amprage. (its an example, I am not buying car batteries)

I am hoping to do this only once... My best guess is the BMS is the most likely candidate for failures. Would one be better or three?

How do I size the BMS if I make what I think Craig is suggesting?

So may questions... Sorry.
 
Craig said:
Put your batteries in parallel first then in series so you only need 1 bms. Search aliexpress for a dalt BMS that meets your charging specs.
Click to expand...
Can you provide a diagram for "parallel first then in series", please?
 
Bigbillsd said:
Thanks guys, 12v is what I need. I have a fairly small battery box that only fits 4@CR260 LA batteries now so I am thinking I series 4 cells each to make 3 each 12.8v batteries. Then Parallel them into 600AH The spec says those batteries are SINOPOLY model SP-LFT200AHA I would like to be able to draw up to a max of 300amps from the pack, which looks like 1/2 of their capability, as they are rated 1C which should allow 600 amps continuous draw if I understand this part.

We currently pull about 250AH from our LA batteries in 24 hours (measured by a Trimetric, soon to be a Victron BMV) I am hoping to get up to 3 days of dry camping from them during minimal solar energy production.

I am still a bit fuzzy on the BMS as Craig said to put them in parallel first. I am looking at 12 cells of 3.2v 200AH.

Is he saying to make 4 batteries @ 3.2v using 3 cells each paralleled connected, and then put those 4 resultant 3.2v "batteries" into a series to make the the 12.8 @ 600ah? How does that help? I am still dcyphering the greek..

I had assumed I would make 3 batteries @ 12.8v (4 cells) then parallel them together. Kind of like buying 12v car batteries and paralleling them together for the higher amprage. (its an example, I am not buying car batteries)

I am hoping to do this only once... My best guess is the BMS is the most likely candidate for failures. Would one be better or three?

How do I size the BMS if I make what I think Craig is suggesting?

So may questions... Sorry.
Click to expand...
Don't be sorry all questions are goid questions.

Yes place 3 batteries in parallel all positives tied together then all negatives for the 3 cells. This will in effect make 1 cell. Now put those 4 cells you made in series. The bms will hook to each cell and do it's thing.
 
If you put batteries in series first you will have 3 12v batteries but the bms only works on 1 group of batteries in series so if you did it this way you would need 3 bms
 
Great Video!! I missed that one, and I was looking for it.. Thanks Again. Now to figure out how to size the BMS for my 600ah pack, but never really pulling more than 300amps from it. (I will keep the 300amp fuse currently in my RV) -Bill
 
Earlier he said he was going to take 250 ah a day from it. I might be wrong but Daly 12 volt only go up to 200 amps not 300 amps.
Gee Bill how do you chew up 250 ah in one day in an rv? Bake a roast in an oven and an aircon?
My max is 60ah in a day.
 
Amps and Amp" hours" are not the same. Got to remember the "Time" factor. Catastrophic fusing is not unusual.
 
300 Amps max draw, keeping my 300amp Fuse. 250AH draw per 24 hour period. Its closer to 200 AH today, but I am about to put in a 24 cu ft fridge and sell my current propane/electric model. It still works great, but the interior is really small compared to the outside due to all the "stuff" in the rear. Its supposed to be 12 cu ft, but I think that number is marketing. I feel its closer to 8 cu ft.

Based on a prior post the largest BMS may only be 200amps?

-Bill
 
For reliability, I would suggest a 300 Amp BMS (or relay if controlled that way)
 
Turns out when I wanted to buy the Sinopoly batteries, they are not available. But they are saying these CALB ones are. And at the same $783 for a 200AH battery when buying 3. Is CALB a brand? If so, is it something folks here would buy?

www.dhgate.com

Deep Cycle Batteries Lifepo4 CALB Battery SE200 AHA 3.2V 200Ah For Energy Storage System/Telecommunication/UPS/Power Wall Best Variable Voltage E Cig Digital Camera Battery From Ecodream, $193.97| DHgate.Com

Wholesale deep cycle batteries lifepo4 calb battery se200 aha 3.2v 200ah for energy storage system/telecommunication/ups/power wall on DHgate.com are on sales now. Quality is guaranteed by ecodream. best variable voltage e cig, digital camera battery and ecig batteries variable voltage are top...
www.dhgate.com
 
Bigbillsd said:
Turns out when I wanted to buy the Sinopoly batteries, they are not available. But they are saying these CALB ones are. And at the same $783 for a 200AH battery when buying 3. Is CALB a brand? If so, is it something folks here would buy?

www.dhgate.com

Deep Cycle Batteries Lifepo4 CALB Battery SE200 AHA 3.2V 200Ah For Energy Storage System/Telecommunication/UPS/Power Wall Best Variable Voltage E Cig Digital Camera Battery From Ecodream, $193.97| DHgate.Com

Wholesale deep cycle batteries lifepo4 calb battery se200 aha 3.2v 200ah for energy storage system/telecommunication/ups/power wall on DHgate.com are on sales now. Quality is guaranteed by ecodream. best variable voltage e cig, digital camera battery and ecig batteries variable voltage are top...
www.dhgate.com
Click to expand...

typical cost we pay from the #1 Maker of Lithium batteries in World out of China ..
For 4pcs 3.2v 202ah LFP Cells -- $110 ea.. total USD440
For 10 busbar with M6 screws, - $2/pcs, sub total USD20
Shipping fee to door: USD155 - UPS/DHL - insured -
Plus PayPal added fee: USD31 (we use Paypal to insure we get the battery)
Total: $646 For a 12.8 200aH LiFePO4 battery .... Pretty good in my opinion
 
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