# Lightweight batteries?



## Blake (Aug 31, 2015)

I'm trying to save a little weight and was wondering what I could get away with for my cranking battery. 

The motor is an electric start 02 yami 25 horse. Other things the battery will be running will be an 11" led light bar, nav lights, two depth finders, livewell pump, and bilge pump. 

The only things that will be running when the motor isn't are the livewell pump (but I seldom even have any water in the livewell) and depth finders. 

I hear people say that they've run those little lawnmower batteries in situations like this. I'm not sure if I want to go to that extreme, but I'd sure like to cut some weight. 

Thanks!


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## TNtroller (Aug 31, 2015)

The lawnmower battery will start the OB w/o issue, and power the other accessories as well, however, they do have limited reserves so it's possible the FF's/lights/ being run will drain the lawnmower battery to the point the OB won't start. Does the OB have pull start and charging capablities?? Might just go with a grp 27 deep cycle or dual purpose and focus on balancing the load now.


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## Blake (Aug 31, 2015)

there is no pull start on the motor, I've thought about adding one but I don't want to spend the money. And yes, the motor does charge the battery.


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## Texas Prowler (Aug 31, 2015)

Agm batteries are generally lighter.


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## DaleH (Aug 31, 2015)

> AGM batteries are generally lighter.


Maybe, maybe not ... be very careful when looking at _comparable specs_, as in cranking/reserve performance, as well as size and weight.

FWIW when I considered AGMs on my toona boat, those of the equivalent rating to the wet cells were actually 5-pounds heavier.

So it really needs to be analyzed on a case by case basis.


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## TNtroller (Aug 31, 2015)

Keep it simple and inexpensive (for the most part) or try and save a few # and it can get expensive and complicated. LOL


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## minuteman62-64 (Sep 5, 2015)

I used the smallest marine starting battery on the Walmart shelf. Don't know the exact weight, but, since I've installed it I've lost about 15 lbs. and I'm guessing that makes up any weight difference over a lawn mower battery


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## Fishfreek (Oct 21, 2015)

I'm glad I came across this thread. I have been researching the lawn tractor battery idea for a while now.

I will be using a lawn tractor battery for starting the outboard and running L.E.D. nav lights. my tinny will have a grab bar with wrap around to hold the cooler / seat. i am having a small box built onto the grab bar to hold the gps and in the box I will have a 12v alarm system type battery that will also be wired to the motors charging system. Then when I get that far I will put the trolling motor on a separate Lithium Ion deep cycle battery up front a group 31 only weighs about 28 lbs.


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## bptjr (Nov 4, 2015)

I went to a lawnmower battery about a year ago. I fish about 200 .days a year. The battery powers electric start on my 9.9 honda with 12 amp charging @ wide open. Also powers lowrance hds10 & elite 7 & bilge pump. One thing i found out was one big draw is from how you set the backlight brightness on depth finders. I know this sounds minor but if you will connect a amp meter between battery neg. Terminal and cable then turn on only one dephhfinder at a time and play with backlight brightness you will be surprised at the draw when on different brightness. A lowrance will turn off at less than about 10.5 volts. You can set batt. Volts to show on screen. If i use mine long enough that lowrance shuts off the outboard wont electric start. I pull start it and a good blast around get it back to normal. Hope any of this helps.


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## crazymanme2 (Nov 4, 2015)

I have lawn mower size AGM bat which is 5 years old with no problems. I will see the model # & post when I get home. I can pick it up with 1 hand.


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## misunderstood (Oct 20, 2016)

crazymanme2 said:


> I have lawn mower size AGM bat which is 5 years old with no problems. I will see the model # & post when I get home. I can pick it up with 1 hand.


Is anyone else as concerned as me that he hasn't got home yet to post the model number :lol:


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## turbotodd (Nov 14, 2016)

I assume it's a 4 stroke 25hp. They didn't come with a backup recoil starter. Why I don't know. 

A small lawn mower battery will crank that thing no problem. I have used motorcycle batteries in mine before. IIRC, it was a well-used YB10A-A2 out of a bayou 220 or 250-can't remember. Little tiny thing, weighs like 6 lbs. There is a lithium version available too. The box that it comes in weighs more than the battery itself.

I personally use a blue top Optima, 39 lbs. But I also run the trolling motor with it and need the capacity. Beats the 68 lbs Wal Mart 27 series that I used to have; and no more than I use the boat anymore, the smaller optima works fine. It's never once been even low even after trolling for a number of hours. It replaced a red top that was in the boat before. The red top was in several race cars and 2 tractors before it went into the boat, purchased 1/18/2001 and retired it October of 2015.


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