I have a one year old 27 or 24 series ever start battery for my cranking battery, I charge it and holds at about 12 volts and after 4 hours of running the live wells and fish finders, starting and motor trim I get low voltage warnings at 11 to 10.5 volts. Is the battery bad or do I need a new one? It was on a tender all winter. The motor charges the battery while running 14-16 volts based on rpms. But the battery still dies even when charged on a battery charger for 4 hours. 10 amp charger.

I would check the water level in your battery and add if needed. If you're still having issues, I'd be looking into getting a different battery

You may need a separate battery for cranking and engine operation.   I do not own a boat but the people I fish with have more than one battery running their boat.  Even the smaller fishing boats have more than one battery. 

It will also make a diffrence if it is a cranking only or dual purpose battery. Cranking only batteries will not last as long running electronics and other items. 

I had a similar issue. The cranking battery that came with my boat just lacked the CCA needed to fire up the outboard after running electronics all day. Invested in a more "powerful" one at the same size and have had zero issues since. I run a powerpole micro, livewell that circulates all day and fish finder. No issues on a group 24 cranking.

I have two batteries, one for my tm, and one for my electronics/cranking, another thing I noted was every great once in a while my graph will freeze up and fuzz out when I start the engine. I topped off with distilled water and put a good charge, samething. Should I run another battery for my cranking battery? 

I have two batteries, one for my tm, and one for my electronics/cranking, another thing I noted was every great once in a while my graph will freeze up and fuzz out when I start the engine. I topped off with distilled water and put a good charge, samething. Should I run another battery for my cranking battery? And if I just replace it what kind of battery should I get?

Get the biggest dual purpose battery you have room for that has the MCA your outboard requires.

The only battery I have found that will run 2 hds units and an aerator then have enough juice to crank an Optimax is the 1150 CCA AGM battery from Sears.

The Diehard PM-1 group 31 has been a popular one, but in not carried by Sears anymore.

I think there is a Odyssey battery that is equivalent.

I have a two battery system on my center console. Cranking battery and a battery that runs all the graphs/radio/TM. Only running one battery seems like it would drain that battery pretty quick. 

One large 24 series for cranking and 2 smaller for all else on my boat. I run my live wells and 2 small finders TM and what ever else all day on 2 hot batteries. 

I have heard of the cranking battery no being able to keep itself charged off just the motor bass fishing. A bunch of starting and short runs to another spot doesn't give time to charge back what it took to crank. 

Think about what you are requiring of a battery. You want starting power (MCA) plus you want it to function as a deep cycle battery to run your stuff when the outboard is not operating.

That takes a battery with the reserve capacity and MCA to do both. A dual purpose battery is the best type for those needs.

Gotchya, I'm picking up a Napa gold series dual purpose 27 series marine battery for the cranking and electronics. The TM has its own battery which is also a 27 series dual purpose. 

On 6/23/2016 at 3:27 AM, Scorchx1245 said:

Gotchya, I'm picking up a Napa gold series dual purpose 27 series marine battery for the cranking and electronics. The TM has its own battery which is also a 27 series dual purpose. 

If you run that one down in 4 hours you have bigger issues! That battery should do you well. What charger did you leave it on when stored? Does that charger have a float/maintenance mode or just trickle 1-2ah output? 

It was on a battery tender.