Starter Battery

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I am running a 14' V boat with a Yamaha F25 electric start. I bought an interstate deep cycle when I bought the motor last year and was using that as the starter battery, but have since read that the charging system in the motor can ruin a deep cycle battery. Is this the case across the board, or depending on the size of the motor.?
 
I am running a 14' V boat with a Yamaha F25 electric start. I bought an interstate deep cycle when I bought the motor last year and was using that as the starter battery, but have since read that the charging system in the motor can ruin a deep cycle battery. Is this the case across the board, or depending on the size of the motor.?
Same for Suzuki DF9.9.
 

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Not as much damaging the battery, but more like not charging it all the way up which could cause battery problems over time. Deep cycle batteries need topped off after use to keep them healthy, the small charge from an outboard is usually not enough to fill them. If you finnish charging your deep cycle at home back to full, you will be fine.
 
I am running a 14' V boat with a Yamaha F25 electric start. I bought an interstate deep cycle when I bought the motor last year and was using that as the starter battery, but have since read that the charging system in the motor can ruin a deep cycle battery. Is this the case across the board, or depending on the size of the motor.?
I did the same when I first got my boat. It's been three full seasons. I store the battery inside the shop in the winter and recharge when on the boat as it is hooked to my two bank onboard charger.

No issue to date.

In my view, only worry about it if you run into problems with that battery.
 
I did the same when I first got my boat. It's been three full seasons. I store the battery inside the shop in the winter and recharge when on the boat as it is hooked to my two bank onboard charger.

No issue to date.

In my view, only worry about it if you run into problems with that battery.
Your onboard charger tops off the battery, you should be good.
 
It's already been said but plugging the batteries into a charger after use to top them back off will keep them healthy. Most outboards just don't have enough charging amps especially at cruising rpm to fully charge a deep cycle. Manufacturers are getting better at using bigger alternators for all the electronics we use these days but only so much can be done with smaller outboards
 
I've run DC batteries in my small boats/motors for many, many years, including my current one. I have never had an issue in my small boats, and I get very good life out of my batteries, and have never killed a motor yet. In general, a little 14' tin boat won't have anything in it that will put much of a dent in a big deep cycle's capacity, unless you are using it to run a trolling motor. For that, you probably want a separate battery.

If you really run it down, you will need to use a charger to top it off when you get home. It's not good for the charging system of the motor to try and charge up a big battery like that. It can/will overheat the system.

That being said, some high-thrust kicker motors have a large capacity charging system intended to recharge larger batteries. I can't remember which one it was, but one of my kickers had a 35A charging system. The Yamaha 9.9 HST maybe?

Either way, a little basic common sense goes a long way. IF you don't sit a long time, using a lot of electricity, it won't be an issue, BUT THAT BEING SAID, if you have a new motor that is still under warranty, follow the manufacturer's suggestions carefully!
 
The Yamaha manual says nothing about deep cell batteries, it just specifies the minimum ratings. In any case, I have two interstate deep cells in good condition. I was planning to commit the older one for the house system and the newer one for the trolling motor. I can get a new starter battery, not a big deal, but I was wondering if it ok to use an auto battery for the motor? I happen to have a new interstate truck battery which is going unused at the moment. Not trying to skimp, but I just spent 200+ bucks on it and it is just sitting on my shop floor.

Thanks for all the helpful replies.
 
The Yamaha manual says nothing about deep cell batteries, it just specifies the minimum ratings. In any case, I have two interstate deep cells in good condition. I was planning to commit the older one for the house system and the newer one for the trolling motor. I can get a new starter battery, not a big deal, but I was wondering if it ok to use an auto battery for the motor? I happen to have a new interstate truck battery which is going unused at the moment. Not trying to skimp, but I just spent 200+ bucks on it and it is just sitting on my shop floor.

Thanks for all the helpful replies.

I'd use that battery in a heartbeat. Put it in a box, secure it, and away you go. The only thing that might give me pause is the physical size and weight of the battery. What group is it? But if it fits....

The issue about deep cycle is about how it discharges and how battery life might be affected by certain types of uses. If your Yamaha 25HP outboard is running well and is easy to start, it's not likely to destroy a deep cycle battery in my opinion.
 
a 25 doesn't take many CCAs to start. I would use any of them. They are certainly far above the minimum ratings, but I would check, just so you know.
 
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