Deep cycle?

[Genie Aye]

It would to be great to have a Agm starting battery and 2 DC house batteries, but where to put them?
I use 2 group 27dc delays, I power alot of equipment, more than alot of bigger boats.
I would not be suprised to see merc require a Agm for starting, alot of cars do.

I was just stating that a DC battery will work fine for starting 90% of the outboards out there. Most do not require over 450amps to start, even a centennial battery might do that...maybe.

[spareparts]

if its got a computer on the engine, the manufacture its most likely requiring at least 850 CCA. Mercury requires more on their Verado's. Unfortunately, the only thing available to meet Mercs spec that will fit in the box is AGM batteries, I throw those POS in the pile all the time, especially the optimas. 30 years working on boats, very hard to beat a Deka 24M7 starting battery. BTW, you cant mix AGM batteries and wet cell if they are charged by the same source.

[THEFERMANATOR]

Originally Posted by spareparts

BTW, you cant mix AGM batteries and wet cell if they are charged by the same source.

You can IF you properly isolate the batteries from each other. RV's routinely use lead acid batteries for starting and agm for the house loads. They install an isolator so the alternator charges each battery bank individually off of 1 alternator. Or you can run a dc to dc charger or charging relay setup to also do it. You just have to use a system so different battery types are not paralleled at rest because agm batteries have a higher static voltage than lead acid do, so if you mix them, the lead/acid will constantly drain the agm battery at rest.

[Genie Aye]

Correct, AGM and lead acid charge differently, that is why most AGM batteries die early.

I have had no computer issues with my Evinrude and the computers in 10 seasons with all the computers on her.

Just my experience and opinion, if you gave me a Merc verado....i would not take it.