I'm replacing my start battery
to (hopefully) improve my issues with getting the engine
started up. The problem is, I can't seem to find the correct battery
. The owner's manual calls for a battery with at least 660 Cold Crank Amps / 780 Marine
Crank. The manual also specifies at least 120 Ah. The manual does not specify a reserve capacity figure. My current
house bank, start battery, and generator
start battery are all AGM
, so I'm sticking with that.
Now, the batteries
I can get my hands on locally don't seem to fit the bill. I can find lots of options that meet the CCA requirement. 700-1000 are available at various price
points in AGM batteries
. The Ah spec is where I get into trouble. The highest Ah battery I've found hits 105 Ah. My currently installed battery is also 105 Ah, so that's probably good enough. However, this is the most expensive battery by far at $320.
It seems to me that the spec on Ah is much less important on the dedicated start battery. Literally the only thing this battery runs is the Yanmar's starter motor
, so I don't see any reason that it should need so much capacity. However, I also don't know much about batteries, so I'm asking the experts here. I can get a 750 CCA battery with 90 Ah for $150, which seems a lot better. Plus, it's a smaller box which is always nice. Is there any reason to think that one won't work