Connect 2 lead acid batteries

Wave53

I wish to connect 2 batteries in parallel. Group 27, 80 ampHr, 12 volt lead acid, with a AGM, group 27, 75 ampHr, 12 volt. The lead acid battery is about 2 years old, the AGM is 2 months old. Will I have any problems to connect these. The application is to support a basement sump pump and I want to have the additional ampHr that connecting them in parallel will provide.

VatrerPower

Connecting two batteries of different types and capacities in parallel isn’t generally recommended. Mixing a lead acid battery and an AGM (Absorbed Glass Mat) battery, especially with different ages and capacities, could lead to several issues.

Wave53

VatrerPower Thank you for the reply. I wasn’t sure anyone would chime in, so thank you for that advice and I think I will stay away from joining those two batteries.