Wire size for running 3 Lipo4 in Parallel

[Boone73]

Hi, adding a 3rd battery ( I know its not ideal, but they are from the same manufaturer, size is the same, etc) battleborn 100amp hr. currenty there is 4 awg wiring them in parallel, would it be wise to change the wire sizing to 2 awg with the added current? currently running a small frig, some lights, max air fan and a propane heater when needed.

 

[landyachtman]

Please introduce yourself in the Newcomers Corner.

 

[bullfrog !]

Hi, adding a 3rd battery ( I know its not ideal, but they are from the same manufaturer, size is the same, etc) battleborn 100amp hr. currenty there is 4 awg wiring them in parallel, would it be wise to change the wire sizing to 2 awg with the added current? currently running a small frig, some lights, max air fan and a propane heater when needed.

A lot will depend on how long the runs are and if they are strictly house batteries or will they have vehicle start capability as well. Welcome!

 

[INTJohn]

Probably a Q you could run by BattleBorn.

Larger wire generally is never a bad thing but 2ga can get expensive if you’re making long runs.

INTJohn

 

[rruff]

Are the batteries next to each other?
What is the max current that you will draw?

If they are 100A max and are all next to each other, and you tap from the center battery, 4awg pure copper should be fine to connect them, even with a 300A draw.

 

[twomountainlions]

You are not really adding the current when you are connecting batteries in parallel, you are increasing bank storage capacity and you are not increasing draw on your system since you are not adding new appliances.
Battery bank still produces 12v and the appliances wattage remains the same too, so you have the same amps going through the wiring, your battery bank will just last longer but it does not produce increased current.

If you do expect to add more appliances in the future, you base gauge off their maximum starting amps and the length and type of wire (copper, etc) lookup in gauge tables.

 

[jonyjoe303]

4 gauge is fine for what your running. I have 15x 26ah batteries hooked up in parallel and they are all connected with 14 gauge wire. On my system the most amps I run is 12 amps from my roadpro cooker, the fridge uses about 4 amps.
No need to go to 2 gauge unless your planning to run a microwave or something that requires more amps.

 

[thegoodtom1]

Something to consider when using multiple batteries is your wire lengths. Electricity will travel the least resistance (like water does) and may 'use' a battery much more than the others. I like to use equal length wires from my batteries to a combining block (both pos+ and neg-) and then connect monitors,fuse blocs, appliances and chargers to the combiners. This ensures an equal charge and discharge from each battery in the system.

 

[maki2]

Hi, adding a 3rd battery ( I know its not ideal, but they are from the same manufaturer, size is the same, etc) battleborn 100amp hr. currenty there is 4 awg wiring them in parallel, would it be wise to change the wire sizing to 2 awg with the added current? currently running a small frig, some lights, max air fan and a propane heater when needed.

Did you take the time to look for that information on the Battleborn website? Battery companies usually have a consumer advice section on wiring up a bank of their batteries.

 

[Boone73]

Are the batteries next to each other?
What is the max current that you will draw?

If they are 100A max and are all next to each other, and you tap from the center battery, 4awg pure copper should be fine to connect them, even with a 300A draw.

yes, they are close to each other. draw is low, a small frig, some lights and fans, occasionally a propane heater

 

[Boone73]

Something to consider when using multiple batteries is your wire lengths. Electricity will travel the least resistance (like water does) and may 'use' a battery much more than the others. I like to use equal length wires from my batteries to a combining block (both pos+ and neg-) and then connect monitors,fuse blocs, appliances and chargers to the combiners. This ensures an equal charge and discharge from each battery in the system.

combining bar same as buss bar? I am adding those to the system now, interesting with the equal length wires, I will see if I can make that work