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24V- 12V in series VS 24V in parallel?

Salmonberry

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Greetings! I am building my off-grid 24V system and its time to buy some LiFePo batteries... I'm need to choose between 2 200A 12V batteries in series or 2 100A 24V batteries in parallel. At approx. $2000 either way, which is better?

Thanks,
Erik
 
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Two 24v in parallel will avoid the potential issues of two series connected batteries getting out of balance.

It also has more redundancy, if something happens to one battery (failure or bms cutoff) you still have the other keeping the system going. With two in series everything goes down if one battery has an issue.
 
Two 24v in parallel will avoid the potential issues of two series connected batteries getting out of balance.

It also has more redundancy, if something happens to one battery (failure or bms cutoff) you still have the other keeping the system going. With two in series everything goes down if one battery has an issue.
That is my style of coaching!
Thanks,
Erik
 
Two 24v in parallel will avoid the potential issues of two series connected batteries getting out of balance.

It also has more redundancy, if something happens to one battery (failure or bms cutoff) you still have the other keeping the system going. With two in series everything goes down if one battery has an issue.
I thought I heard Master Prowse give some advantages to the 12V series system, but watched so many videos it has become blurry in my old brain.
 
I thought I heard Master Prowse give some advantages to the 12V series system, but watched so many videos it has become blurry in my old brain.
Two 12v in series might give you some more flexibility depending on the circumstance, or be easier to source locally. That's all I can think of ?
 
Two 24v in parallel will avoid the potential issues of two series connected batteries getting out of balance.

It also has more redundancy, if something happens to one battery (failure or bms cutoff) you still have the other keeping the system going. With two in series everything goes down if one battery has an issue.
I have a similar question: I just bought 2 new 12v/100ah batteries (the Epoch version of the Roypow “battery porn” video Will did. LITHIUM SOLAR did a video on the battery) and a Roypow 14.4v/15a lithium charger. If you were buying a trolling motor would you get a 12v motor with batteries in parallel (50a max draw), or a 24v motor with batteries in series (25a max draw)? Is one better for battery longevity in the long run?
 
Greetings! I am building my off-grid 24V system and its time to buy some LiFePo batteries... I'm need to choose between 2 200A 12V batteries in series or 2 100A 24V batteries in parallel. At approx. $2000 either way, which is better?
Two 24v in parallel will avoid the potential issues of two series connected batteries getting out of balance.

It also has more redundancy, if something happens to one battery (failure or bms cutoff) you still have the other keeping the system going. With two in series everything goes down if one battery has an issue.
For my shed project, I decided to go with a 24V system with four 12V 100Ah batteries, in a 2S2P setup. This creates 24V-200Ah (5.12kWh) storage. I like the modularity of 12V batteries in this way. At $300 a pop, I can easily add storage capacity by adding another 2S in parallel to this bank for $600. With rackmount batteries, each increase is $1500, for comparison.

Like Charleswgibbs mentioned, I'm wondering if those in series will become mismatched in time, but I'll be keeping an eye on that. I don't know how two separate BMSes will manage things in series, but manufacturers are saying you can combine these up to 4 in series without a problem. I'll "trust, but verify."

Brent
 
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