Battery requirements for 9.8 4 strokes

I have a couple of 9.8 Tohatsu 4 strokes on my boat. Both have electric start and each have their own battery, each one wired separately to each motor for reasons too long to go into here. (I do have the ability to temporarily jump one side to the other if needed)

My question is, what are the cold cranking amp and other requirements for these engines? Each battery is used to start it's own engine and to run one or two LED lights, as well as charging an iPad used for navigation. I will also eventually use a small VHF radio for occaisional use only, as in calling ahead to a harbormaster for a mooring, or for an emergency.
The batteries I have now are Big, heavy and are overkill and I would like to downsize. Any recommendations?

Thanks for any help!

Lincoln

AH rating for the MFS9.8A3 is surprisingly small. That said, you will want some deep cycle amps in reserve for the VHF and accessories. On page 26 of the newest MFS9.8A3 owner's manual, the factory recommends a minimum of either 40 AH or 70 AH, depending on the battery manufacturer. In other words, a group 24 deep cycle flooded battery is more than adequate. We have successfully run these motors with a 35 AH AGM deep cycle battery as well.

Paul, thanks for your help!

Lincoln

Paul,

Just out of curiosity, what are the manufacurer's recommendations for minimum CCA and amp/hours?

Lincoln

See my post above, and page 26 of your owner's manual, regarding that model.