Battery charging query

[sogood]

Am I right in assuming that whichever battery I am using in a dual battery set up, is the one that will be charged by the alternator. I have a 1 or 2 or 1+2 battery switch, so what happens if both batteries are selected. Does the weaker one take the charge automatically and which one then starts the engine. Thanks in advance.

 

[Silvertip]

Both run everything and both are combined to start the engine as well as being charged in 1+2. It is as though you have one large battery rather than 2 small ones.

 

[sogood]

Thanks for that. Curiosity put to rest!