Well Now,
The question you are asking has some ramifications that many do not know about.
Assuming (you know what they say about that) that you have a more or less run of the mill portable automotive battery charger, then yes, you can charge the bank with it all connected.** I suggest that you keep a mental track of the discharge and about every full discharge, you separate and recharge each battery to 100% density.
** There is, however, a problem. You will probably not be able to recharge the bank (pair of 12V in you case) to 100%, simply because lead/acid batteries do not like to play with others. One will hog and no let the other have the juice. They could be consecutive serial numbers and this would still be a cloud.
Back before the depression, I did a lot of work on other people's expensive boats. This is something I ran into often. So, it is in convenient, but you can survive it.
Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.
