Question about LiFePo Connections

[Phalanxguard]

All, I've been wondering, LiFePo batteries that are rack mount always seem to have an "in" and an "out" terminal for both the positive and negative connections. I'm wondering if there's any reason for this other than convenience. To avoid as much as possible unequal voltage drop across the batteries, I was considering linking all of the positive terminals and all of the negative terminals up with a long 70mm2 copper busbar on each side and shrink wrapping insulation onto the parts that don't need to be exposed. Anyone have any idea if there could be any issues with this setup?

 

[AZ Solar Junkie]

Bus bars are much more preferable vs. connecting the batteries together using those in and out terminals as all the batteries have access to roughly the same amount of current as the bus bar introduces far less resistance vs using the in out terminals means the current getting to say the last battery in the stack has to go through more cables and terminals than the first battery in the bank - so the last battery charge for example would lag in charging vs the ones higher in the stack. The bus bar setup is much cleaner. I agree - those in/out terminals are there more for convenience than anything else so you do have the option to run without needing to get bus bars.

 

[Phalanxguard]

Thanks for the reply, that confirms my suspicions, I wasn't sure if internally between the links they might have had fuses/shunt or something. I'm actually thinking I could probably cheap out and use 100mm2 aluminium bars for half the cost!

 

[MisterSandals]

suspicions, I wasn't sure if internally between the links they might have had fuses/shunt or something.

Open it up! Share a pic.

 

[Phalanxguard]

Open it up! Share a pic.

Certainly will sir! I used a stock photo above though, sadly I have to wait until January for my 25kWh of batteries to arrive!

 

[Crowz]

There is no real in and out to the posts on the batteries and yes bus bars beat the crap out of the daisy chain junk they are going with now.