# and Type of house batteries

BFL13 wrote:

ron.dittmer wrote:
My personal experience with motor home batteries......

Two smaller 12V batteries will not perform better over time compared to one larger battery. They will when new, but year number 2 will have noticeable degradation. Year number 3, they will be working against each other. Indication of battery mismatch will show up as acid boil-overs.

I do feel that two 6V batteries of a smaller size will perform better than a single 12V battery of a larger size.

To clarify the report, were those two 12v batteries "balanced" as in the loads and charging were "across" the two, or were the loads and charging on one of them with the second battery "downstream"?

BF - good point.

I don't see how a couple of 12 volt batteries connected in balanced parallel can ever have one working against the other. After all, with two in balanced parallel what it seems that you really have, electrically, is six (6) double plate size 2 volt cells stacked in series to produce 12 volts - of greater current capability than only one 12 volt battery with it's hence smaller plate size 2 volt cells stacked in series.

Two 12 volt batteries connected in unbalanced parallel is another situation altogether, since when supplying or receiving current the two 12 volt batteries do not have the same potential across their plus and minus terminals. Over time this will cause different age-related plate and/or electrolyte degradations between the two 12 volt batteries.