Connecting 2 - 12v batteries in parallel to TT

[RitaB]

Last year I had my Travel Trailer battery upgraded to a 2 battery bank, in hopes of doing some boondocking. This was done at my RV dealers. The mechanic seemed to know what he was talking about, it all just confused me. Also had him install a battery disconnect. Never really looked closely at it until I was removing the batteries to store for the winter. The batteries were connected together in parallel correctly, but contrary to diagrams I saw, the positive and negative connections to the TT were both on the one battery instead of positive on one battery and negative on the other. Also I was some deposits on the negative terminal of the second battery. The second battery was a couple years older but I had always kept it charged and really didn't do much traveling then. I figured I could hook the up according to the diagrams I saw on the internet when I dewinterized. Well, both - and + lines are only long enough to reach the first battery.

My question is if this is an acceptable way to connect the power to the TT or could the deposits on the terminal be caused by this set up or the difference in age of the batteries?

I am leaving on a trip which includes 4-5 days of boondocking on 5/9 and don't know what I can do safely.

[Duckogram]

The setup you describe is acceptable however, as you ellude to, certainly not optimal. Think of pairing an older battery with a new one as creating a weak link in a chain.
As for drawing power off of one battery in parallel, you will gain capacity but it is “filtered” through the primary battery. Then there is charging...

[Flybob]

Not a significant difference on the battery connections. The bigger issue for me is the difference in the age of the batteries. With the difference you list they will discharge and charge at different rates. This can cause one battery to overcharge while trying to bring the other up to voltage.

[RitaB]

Thank you for the replies. I know I will need new batteries. I am just trying to use these for a while then get 2 new ones. I was really worried that the way the tech connected them to the TT would cause damage to the system. When I get the new batteries I will make sure he connects as per the diagram.