Motorcycle or lawn tractor battery for starting?

[olcah]

Planning to wire up electric starting for a 1956 Johnson 30 hp motor. I recall in another thread that a regular car battery would start a 25 HP motor for a couple of weeks before having to recharge. To save space and weight has anyone tried a motorcycle or lawn tractor battery? If so how many starts/long did it last between recharges?
Thank you.

[wbeaton]

I use a small AGM deep cycle starting battery. It fits in a box the size of a army ammo box. Any battery capable of starting a motorcycle or lawnmower will work. Keep in mind that a 56 is 6V unless you’ve already converted to 12V.

Wayne
Upper Canada Chapter

uccaomci.com

[olcah]

Wbeaton can you describe how long or how many starts before recharging?

[wbeaton]

Sorry, I can’t. My motor has a charging system. it should last a very long time. My friend uses the same battery. I don’t know how often he charges it, but I know it lasts all week while he’s at the cottage without missing a beat.

Wayne
Upper Canada Chapter

uccaomci.com

[olcah]

It’s surprising that no one has tried the idea of using a small cheap battery for outboard starting on motors without charging systems. Or maybe it has been tried but results were not good? – Not enough starts before battery is discharged?

[2fast4me]

Ocala, the small free batteries that I use Come from the recycle pile at work, it seems that when an airplane owner can no longer reliable crank his 200 HP Lycoming he chooses to replace with new. They work fine for my needs. No charging system either. Light weight. Spill proof. Cheep. Jim

2Fast4Me

[garry-in-michigan]

Anything with a 12 to 14 volt, 200 amp output (that doesn’t catch fire or explode) will work. The demand on smaller batteries is proportional to the size and type of starter motor, the the size and compression ratio of the outboard. Newer starter motors in aircraft have rare earth field magnets which are lighter and do not require an electrical input. The Lithium ion batteries have a higher energy density making them smaller, lighter and more expensive. When corners are cut to bring down the cost, they catch fire. There are many options depending on how much you are willing to spend. But be careful what you wish for. . .

[1946zephyr]

Well, I would just go with the cheapest car battery you can get at Walmart and get a solar charger and call it good. Finding a charging system for those motors, is next to impossible, otherwise. The weight and size of the battery, won’t make any difference in the performance of your boat. Just my humble opinion

[jerry-ahrens]

I use a regular group 24 marine starting battery. When I go to Tomahawk, it lasts for an entire week of boating. I ‘ve got to the point that I now leave my battery charger at home. The down side to this is the extra weight of a full size battery, but with the battery placed near the transom, I doubt you could notice any decrease in speed vs. using something smaller. I just like having the reserve cranking power in case of trouble. Having said that, there are many different 12 volt batteries out there that will work. I have one in my John Deere 318 that’s in between a lawn and garden battery and say, a smaller car battery. I forget what model # that battery is, but it cranks an 18 hp Onan with no worries.
Be sure that whatever you choose is mounted securely in the boat, and inside a marine battery box for short protection. A loose battery falling over in an aluminum boat is a bad thing!

[garry-in-michigan]

It must be secured – In rough water a bouncing battery coming down while the boat is going up can be a disaster. . .

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