Battery cabling/connection

raydias
raydias Solar Expert Posts: 68 ✭✭✭✭
I currently have a 300ah (6x50ah gel 12v batteries) battery bank connected to a buss bar via cables. Each battery has a cable going to a + or - buss bar. From there I connect a charge controller to the buss bar. I am going to be replacing the smaller bank with a larger and am considering a design change. Instead of using cable to connect each + and - to a buss bar i was considering a flat copper bar connecting all the + of each batter together and another connecting all the - together. I would then connect the charge controller + and - cable to opposite ends of the battery bank copper bar.

Reason for doing this is I have the copper flat bars already and don't want to spend more money to get new cables for the batteries if I can help it. Is this a reasonable design idea or is it a bad idea?

Any pitfalls to look out for?

Would this prevent me from adding another charge controller or inverter to the design?

thanks for your help

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Battery cabling/connection

    What's the new battery bank going to be? Same type batteries, only more?

    The problem with connecting batteries with hard stock instead of wires (and yes I have done this) is the lack of flexibility. The holes being just big enough to fit the posts makes alignment critical. Going from one battery to another (series interconnect) isn't so bad, but trying to get several batteries on the same set of bars in parallel will not be easy. You do not want holes with a lot of 'slop' either, as it will adversely affect tightening the connections. There is also a concern with multiple parallel batteries needing separate fusing per 'string', just in case. If they're all hard connected then there are no individual fuses so if something goes wrong ...

    Perhaps you could split the difference and use a common negative bar and then use your existing wires to take each positive to a bus bar - through fusing.

    There should be no trouble adding additional charge controller and/or inverter as they would connect to common points on the bars.