question about dual battery compatibility

[JCDriller]

I'm currently running my factory lead acid starter battery and a PC1400 odyssey group 25 house battery. I've only had this combo for about a month and would now like to replace my starter battery with another odyssey. However, I've ready many times the batteries should match. Would I be better off with the additional 3ah offered in a group 34/35 odyssey or should I stick with the group 25 odyssey for a better matching pair?

Thanks!

 

[john61ct]

If paralled as a single bank should exactly match, including mfg date.

If only combined while charging, mfg recommended charging setpoints should be similar.

Unless using a DCDC charger, completely independent profiles, can even be different chemistries.

 

[dwh]

If paralled...

...or wired in series...

…as a single bank should exactly match, including mfg date.

 

[Ducky's Dad]

Install the biggest Odyssey that will fit.

 

[john61ct]

...or wired in series...

Of course. In this context OP's working in 12V only.