Second battery does it need to be same

[Toyelectroman]

Just finished wiring up for a second battery to a perko switch. I did not install an ACR so switching between batteries will be manual. My question is can i get AGM battery as my second battery even though the first is lead? The lead battery isn't even 6 months old so i hate to have get rid of it

 

[alldodge]

I would not mix AGM with Lead Acid (LA)
If the bats are only charged by the boats alternator, you could get away with it, just don't leave them connected together with boat OFF and parked.

Don't use a 2 bank on board charger with mixed bats.
DOn't use a LA charger on a AGM of other way
Could use 2 different chargers and charge individually