This is a question I am not sure I have seen answered.
I know that the batteries in any set should be of the same size age and make.
BUT (yes there has to be a but or I wouldn't have a question)
When going down the road can the house bank be charged from the generator that is on the main engine and is also charging the start batteries and when the engine is shut off the battery banks are separated by a relay or other switching device. So that you can have dissimilar batteries such as golf cart batteries for the house bank (which may be running an inverter while you are driving) and group 31's for the start batteries ( which now have become a part of the house bank because they are connected while the charger is running). It would appear to me that while being charged it wouldn't make a difference what kind of batteries you have as long as they are not connected when the charging system is turned off.
I know there has been a lot of posting about batteries and the current busconversions mag has an article about batteries in it but I don't think I have seen this addressed directly
Melbo
http://www.busconversions.com/bbs/index.php?topic=3859.0
There is a lot of battery information collected on the Help board here:
http://www.busconversions.com/bbs/index.php?topic=3071.0
Scroll down to this heading:
ELECTRICAL SYSTEMS AND BATTERIES
Richard
We do it with good results.
Tom Caffrey
So long as the alternator is set no higher than the lowest battery voltage capability, you'll be alright. Batteries are like tanks of water. If all tanks are the same height, but different sizes, the smaller will fill up first then the bigger ones will follow. As long as the alternator restricts top voltage, say 14.2 volts when charging, you won't get an overcharge on the smaller batteries-the current will just blead off to the bigger batteries that have less resistance. I do the same with good results. Good Luck, TomC
Thank you
It looks like what I have planned will work out just fine.
Melbo