Which Battery of House Bank to Connect to??

[Scrimma]

Hi everyone,

I'm setting up my Dehler 39 for living on with the wife. I have 2x260ah 12v fullriver AGM sealed house batteries and a seperate start battery. They are in parallel, so 520ah at 12v. The STBD battery with nothing else connected to it is connected through to the PORT house battery (approx 2000mm away on the other side of the engine compartment). The PORT battery is the one that then runs to the VICTRON BMV712 shunt etc. My STBD aft cabin is our storage, and therefore I want to wire in my 1000w Pure Sine Wave Inverter there tucked away.

With all that out of the way, I would like to draw the positive for the inverter off my STBD battery (approx 800mm away from inverter location) and then run the negative through to the PORT side approx 2000mm away to the Victron Shunt so i can measure output etc etc. Is there any issues with this? I can't personally think of any problems, but then I'm no electrician. Both batteries are connected in parallel so it seems simple enough...but? Any tips, tricks or ideas?

Thank you in advance!

[Pete7]

Putting aside the inverter for the moment, the house doesn't quite have the optimal wiring, though it will work. The port battery will be working harder to supply loads than the stbd battery, if I have read your description correctly. Depends on what the port positive wire is connected to, stbd battery or a positive bus bar. Have a read of this to see the difference,

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

[Scrimma]

Thanks for the reply. The STBD battery is connected directly to the positive and negative of the PORT battery. No bus.
I have a feeling with nothing to back it up other than my gut, that the PORT would always be 'used' more...but they are wired together so it should be very close with the only difference being minimal voltage loss across the 2 meter wire run between batteries...? It's pretty huge wires. Thicker than a man's thumb kinda huge that connects the batteries.

Ill give that link a crack now. Cheers

[Scrimma]

Brilliant article! Thank you for sharing. I'll look into that. I only have the 2 batteries at this stage and they are several years old so I expect them to start failing not too long after moving on full time, at which point I'll throw in a lithium setup and make sure they are wires correctly for balanced charging.

So, I guess my question still remains though unless I missed something. Will it be a problem to connect to the STBD battery positive and then run the negative to the box from shunt? Regardless of how the batteries are linked together as per the link, what is the best way of connecting the inverter in your opinion? Please forgive my ignorance in all this. I'm a tradesman and can do many different trades, but electrical stuff takes a while longer to make it through the skull. ����

[stormalong]

If the wire gauge between the two batteries is sufficient for minimum voltage drop for the full load of the inverter you should not have a problem.

[Scrimma]

Originally Posted by stormalong

If the wire gauge between the two batteries is sufficient for minimum voltage drop for the full load of the inverter you should not have a problem.

Thanks for the advice! That's what I was hoping. The day I go lithium I will have to rewire a bunch stuff anyway I think, so i'll tweak things then in regards to how the batteries are wired together.

Cheers