Charging an uneven system

[Peter_Crowl]

My house battery array consists of 2 x 12 volt Deep Cycle - currently "Marine Deep"...I know but that's what's there...there's also a pair of 6 volt true deep cycle batteries in series. All these are tied together to form the 12 volt house battery array.

So how should I charge them? Since they're all connected, simply connecting a smart charger to the system will cause the 12's to over charge since the 6's have much greater capacity and will be calling for more of a charge. Right?

How can I charge them appropriately in this system?

Thanks for any help

Peter
in Denver

[Wanabee FTer]

I don't think I would worry about how to charge the battery bank, rather I would be thinking about how to get a matched set of batteries installed. You could replace the two 12's with two 6v and rewire them or vice versa. The point is to a have a balanced battery bank that all batteries will charge at the same rate. Even the way you wire up the bank, 12v or 6v can have a direct impact on battery capacity and proper charge rates.
Mixing 6 volt with 12 volt batteries will not allow either ones to last very long.
The 12volt Side of Life (Part 1)

[Ed-Sommers]

It's true that you do not have an ideal system but if they are holding a charge as they are, I see no reason to replace them till they go kaput, which they will.

You have a choice of weather to over charge the 12 volt batts, or undercharge the true deep cycle's, so 14.4 for the 12's or 14.8 for the deeps.

Personally, I would go with the 14.8, but only deep them there only an hour or so rather than the 4 hours recommended (I only keep them at 14.8 for 2 hours).

When they get to the stage where they will no longer provide a night's supply of power, replace they with your choice of true deep cycle batts, matched of course.

IMHO

Ed