beemac
1 kW
Hi all,
I'm almost certain that this will have been asked before - but I've had a search to no avail so apologies if so...
Am building a replacement for a pile of lead acid I have in my campervan. I've ordered 8 LF280K LiFePO4 cells from fogstar (https://www.fogstar.co.uk/products/lifepo4-280ah-prismatic-cell-grade-b) and I plan to box then in a 4s2p configuration for a drop-in 12v battery replacement.
Final capacity will be c.500Ah with a continuous discharge of 250A. BMS is a 250A Daly board.
I plan to use copper busbars for all cell-cell connections (38mm x 3.6mm) = 136.8mm2 which gives a current capacity of 1.2 x 136.8 = 164.16A (apparently 1mm2 of copper busbar supports 1.2A of current from the research I've done).
Question is about arrangement - which is the better of these two arrangements (or is there a better one) - my assumption is that A would mean less voltage difference across cells because it doesn't have the long busbar connections across 4 terminals. But A is less flexible and has to be a long, thin battery wheras B can be arranged into a squarer final battery if required...
In A all inter-cell connections are a single busbar of the spec above (except the first/last cell which would have a doubled-up busbar) - for B all connections are a doubled-up busbar.
Any obvious gotchas or things that might cause me to burn down my campervan?
I'm almost certain that this will have been asked before - but I've had a search to no avail so apologies if so...
Am building a replacement for a pile of lead acid I have in my campervan. I've ordered 8 LF280K LiFePO4 cells from fogstar (https://www.fogstar.co.uk/products/lifepo4-280ah-prismatic-cell-grade-b) and I plan to box then in a 4s2p configuration for a drop-in 12v battery replacement.
Final capacity will be c.500Ah with a continuous discharge of 250A. BMS is a 250A Daly board.
I plan to use copper busbars for all cell-cell connections (38mm x 3.6mm) = 136.8mm2 which gives a current capacity of 1.2 x 136.8 = 164.16A (apparently 1mm2 of copper busbar supports 1.2A of current from the research I've done).
Question is about arrangement - which is the better of these two arrangements (or is there a better one) - my assumption is that A would mean less voltage difference across cells because it doesn't have the long busbar connections across 4 terminals. But A is less flexible and has to be a long, thin battery wheras B can be arranged into a squarer final battery if required...
In A all inter-cell connections are a single busbar of the spec above (except the first/last cell which would have a doubled-up busbar) - for B all connections are a doubled-up busbar.
Any obvious gotchas or things that might cause me to burn down my campervan?