diy solar

diy solar

"Portable" battery build - bussbar type question


New Member
Mar 5, 2023
Cincinnati Ohio
I am in the process of designing and building a "portable" 280 AH LiFePo4 battery. "Potable" in that I will be moving it between our popup camper and large (41') Marinette Marquis cabin cruiser boat. We can't be in 2 places at one time so it seemed reasonable (and economical!) to have the ability to have a battery that could move between the two with us. We don't use the camper that often so the movement between the two will be minimal.

The construction will use a large tool box as the housing of the components. All below components will fit (some already acquired) inside of housing)
- 4 - 280AH LiFePo4 cells (acquired),
- the 280AH cells are to have a 1/16" to 1/8" separator between them,
- 1/4" foam medium density foam cushion (think 'walk/stand on "fatigue reducing mat") on the bottom of the box to absorb jarring during vehicle movement (highly likely pulling camper on road trip),
- a single 20A Victron DC - DC charger, (acquired)
- a Daly 200A BMS (acquired)
- Heavy gauge battery thru wall battery connectors for hookup to the vehicle's feed from the house battery, (acquired)
- #1 (#2 or ???) gauge cables to battery side of 2000watt inverters (1 each in each vehicle - camper already has 1 as I used 2 - 6V golf cart batteries initially but their several years old. Boat' never had an inverter system)
- (not part of 'portable battery' but just FYI) 2000w inverter.

My primary question:
The 280 AH cells I bought (from 18650 battery store) utilize dual buss bar welded on terminals. They came with solid straight nickel coated copper buss bars. My concern is with jostling and possible movement/shifting and the buss bars potential for movement/loss of solid connectivity. To mitigate this, I'm considering making up my own buss bars using welding cable & crimp on lugs. I have a hydraulic crimper to ensure a solid fit/connection.

--> what gauge copper cable would you recommend for the intended buss bars?
.... or do you recommend anything, buss bar-wise, else?
Making cables for cells has proven to not be a good fit many times. If you are worried about movement or stress on the terminals, you can look into compression of the cells to keep them from moving, or flexible bus bars.