6 batteries in parellel

GlamslandGlamsland Registered Users Posts: 8

I an upgrading my 4-batteries bank to a 6 batterybank, and then i am thinking about how to do the wiring the best way ( parallel)

Its 12v/100a agm batteries.

I was thinking of some way to connect the wires in a "mixed" wiring.. not the normal "ladder" wiring.
isnt it better to do the mixed version becouse of the more effective charging current ?
Attachment not found.

What about this?

Sorry about the poor language, i am norwegian.... :D

Any tips?



  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: 6 batteries in parellel

    Welcome to the forum.
    In general, more than 3 parallel batteries leads to problems. I'd expect major problems with 6 in parallel. It can be and almost always is extremely difficult to keep more than 3 parallel batteries properly charge balanced. You'd be far, far better off going with one single larger battery, or a single string of 2 volt batteries in series.
    Also note - - - generally, AGM and gel batteries are very sensitive to "abuse" compared to flooded batteries and are thus easily damaged by overcharging. They are also more expensive and don't usually last as long.
  • TucsonAZTucsonAZ Solar Expert Posts: 136 ✭✭
    Re: 6 batteries in parellel

    Not a super wise idea but if you "must" do it, make 12 leads all exactly the same size, run the 6 positives to a common point and do the same with the negatives and go off of those common points. That will give you the best case with a less than ideal setup.
  • zonebluezoneblue Solar Expert Posts: 1,218 ✭✭✭✭
    Re: 6 batteries in parellel

    And dont forget to add fuses or breakers to each branch. Thats to protect from a shorted string getting the other 5 batterys dumped into it. Thermal runaway boom!
    1.8kWp CSUN, 10kWh AGM, Midnite Classic 150, Outback VFX3024E,

  • sunbunnysunbunny Solar Expert Posts: 59 ✭✭✭✭
    Re: 6 batteries in parellel

    This is what I made to manage a system like that. One could have all batteries or just 2-3 charging or discharging.
    The batteries are attached to the breakers and the inverter and controller to the bus bar.
    There is an equally robust negative bar.
  • BB.BB. Super Moderators, Administrators Posts: 30,530 admin
    Re: 6 batteries in parellel

    I like method 3 from here:


    It allows you to fuse/breaker each battery and use a DC Current Clamp meter to measure charging/discharging/no current flow into each battery.

    Do the measurements (perhaps once per month) when charging/discharging to make sure that all of the batteries are properly sharing current flow. If you have an open/shorted cell or poor cable connection--The DC current clamp meter will quickly show if there are any problems.

    You can, of course, do similar measurements with the "more complex" wiring method (and even use a fuse per battery) with a DC clamp meter--But it will require a bit of math to subtract current flow to figure out the "per battery" current flow.

    Here are some neat fuse blocks that could be used on a battery:


    Attachment not found.Attachment not found.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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