Question for the Lithium Gurus

[IanRJ]

I’ve noticed (YouTube addict) lots of RV’s in the USA have huge lithium battery banks, very prevalent are the Battle Born batteries with 2, 4 even 8 in parallel. However having been investigating lithium in UK recently it seems quite a few lithium suppliers limit the number of batteries that may be paralleled, typically 2.

I am guessing it is an issue with the BMS and perhaps balancing of cells that drives this limitation.

Can any of you Funster Guru’s shed light on why some lithium batteries can be paralled and others can’t?

Just curious!

TIA

 

[Pausim]

Relion say up to 4 in parallel for their standard LiFePO4 ranges but 10 for their InSight range.

Series vs. Parallel Connections Explained

If you're interested in lithium batteries, chances are you've heard of connecting your batteries in series or parallel. This week on the blog, we're breaking down what exactly it means to connect your batteries in series or parallel and when you might want to use one versus the other.

relionbattery.com

I think you are right it is the BMS and cell balancing that limits the number.

 

[IanRJ]

Relion say up to 4 in parallel for their standard LiFePO4 ranges but 10 for their InSight range.

Series vs. Parallel Connections Explained

If you're interested in lithium batteries, chances are you've heard of connecting your batteries in series or parallel. This week on the blog, we're breaking down what exactly it means to connect your batteries in series or parallel and when you might want to use one versus the other.

relionbattery.com

I think you are right it is the BMS and cell balancing that limits the number. the bms being responsible for cutting voltage on over charge/discharge, but not sure how the bms affects using the batteries in parallel?

I understand the bms managing over/ under voltage, and perhaps balancing the cells, but not sure the part it plays in parallel setups. Perhaps these bms are amperage limited hence limited to say two in parallel say 200 ah with 2 * 100ah batteries?

 

[Pausim]

I understand the bms managing over/ under voltage, and perhaps balancing the cells, but not sure the part it plays in parallel setups. Perhaps these bms are amperage limited hence limited to say two in parallel say 200 ah with 2 * 100ah batteries?

I think it is the BMS and accurate cell balancing that is the issue, the Amps should not be a problem with parallel connections. However, I am not a guru.

 

[MobyDick57]

Presently we had 6 x Transporter 100ah lithium batteries fitted two years ago. From memory I think I could have paralleled more. 6 was the max I could fit in the battery storage area on their sides. Not had a single problem with them

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[autorouter]

Series vs. Parallel Connections Explained

If you're interested in lithium batteries, chances are you've heard of connecting your batteries in series or parallel. This week on the blog, we're breaking down what exactly it means to connect your batteries in series or parallel and when you might want to use one versus the other.

relionbattery.com

Don't worry if you're confused. That's about the worst explanation of series and parallel that I've ever seen. He doesn't even understand the difference between amp-hours (Ah) and amps (A).

 

[IanRJ]

Don't worry if you're confused. That's about the worst explanation of series and parallel that I've ever seen. He doesn't even understand the difference between amp-hours (Ah) and amps (A).

I read that and thought it was perhaps not the most authoritative article LOL. Still, it had zero to offer regarding the initial question about why some can be paralleled and some can't (or have limitation on numbers) rather offering some basic info.

 

[Slabraider]

Transporter Energy batteries are the UK brand of Battle Born. They are the best of the best and can be infinitely paralleled providing you use big enough cables. It's all about the BMS and theirs is a very costly piece of kit which can cope with huge banks