Motorcycle battery for small electric start outboard

[Ostinato]

I recently purchased a 10hp electric start outboard because I injured my shoulder. I need to buy a battery for it and the manufacturer claims it needs only 40-70 cold cranking amps. Car batteries look like over kill.

Has anyone had any experience using motorcycle batteries?

[BlackOak]

Should work. The Manu says 40-70 cca, so it doesnt specify car or motorcycle battery. Motorcycle batteries can go from 11 CCA to 300 CCA. Give it a shot and see what happens. My 100hp harley uses 70 CCA battery. Good luck and let us know how it works for ya.

[Rick R]

I have a Merc 10hp elecstart and use a U-1 size battery, but any small battery will do. A lawn mower battery may be the cheapest.

[Wanderlust]

I have a 15hp four stroke with electric start and have just bought a 100cca motor cycle battery. I was previously doing the hand start, but the admiral could not manage this. I must admit I can't imagine me going back to manual if there is a starter.

I bought a motor cycle battery for the compact size. It is about 2/3 the price of small car battery, but much smaller. I have not tried it yet because the outboard is in pieces for service. I will give an update when I use it. Next task is to work out how to mount it without getting in the way and high enough so a little water does not swamp it.

An interesting point is that the battery came dry, with the acid in a separate bottle. Why don't they do car and boat batteries this way so you can be sure they are fresh?

[colemj]

Now that you will have a battery in the dinghy, connecting a small bilge pump and switch is the next thing you will do and never imagine how you got along without it. For that purpose, a motorcycle battery may not have enough reserve power. We use a garden tractor battery that is almost as small as a motorcycle battery, but has good reserve capacity. The difficult part is finding a battery box small enough for these options. We found a very small one, but it is still 25% larger than necessary.

Mark

[senormechanico]

After the bilge pump, why not attach a small solar panel on top of the engine?
When you've got that, maybe an MPPT controller.
While you're at it, maybe a small fridge to keep the beer cold, a GPS, autopilot and a laptop with wifi...

[colemj]

Make fun if you want, but having a constantly dry dinghy and not having to pump it out is worth the (rather jealous) snickers from others. All of our friends look longingly at our dry dinghy while they stand knee deep in water getting muscle cramps from pumping after a large rain. And in the tropics in summer, that is sometimes 2-4 times a day!

Mark

[Ostinato]

I ended up a buying a 265cca Odyssey AGM that supposedly can sit for up to 2 years and not lose its charge. I use the large version for my house bank. Using a dink in the UK is just done as often as we experienced in the Carib so keeping it charged from use is probably not going to happened.

I can see a bilge pump if you're keeping a dink in the water all the time. Certainly there has been enough rain here.

Apparently these size batteries are also used in antique cars.

[HopCar]

Lehr showed a 9.9 hp propane outboard with electric start at the boat show">Miami Boat Show a few months ago. It had a battery about the size of a pack of cards under the engine cover. We cranked the engine several times a day over several days without recharging it. It was a lithiun iron battery. It was very impressive. I think it added a couple of hundred dollars to the price over a regular electric start but I think I'll go for it when they start to ship them.

"An interesting point is that the battery came dry, with the acid in a separate bottle. Why don't they do car and boat batteries this way so you can be sure they are fresh?"

Steve, that's the way most batteries used to come. The term was "Dry Charged". It used to be my job to fill batteries at our store when I was a kid. Maybe my Daddy didn't love me? He let his teenage son play with five gallon containers of sulfuric acid.

[rwidman]

Originally Posted by Ostinato

I recently purchased a 10hp electric start outboard because I injured my shoulder. I need to buy a battery for it and the manufacturer claims it needs only 40-70 cold cranking amps. Car batteries look like over kill.

Has anyone had any experience using motorcycle batteries?

It seems to me a call to the manufacturer should answer that question.

[bobconnie]

Come on HOP CAR, Ya know ya love messin about with acid and stuff !! LOL Gee I thought only old folks knew about filling batterys !! LOL, Ahh wooden benchs, multi line chargers, ahh the old days !! And on the subject, there are some nice plastic motorcycle batt cases available from after market motorclycle parts places, that fit well in my solid dinks, with a little thought, they should work in a rubber dink!! try Google for them !

[HopCar]

Bob and Connie, It was when I found nitric acid in my high school chem lab that things went down hill. As I recall I tried to mix the nitric and sulfuric acids to make gun cotton. It didn't go well.

[nimblemotors]

Originally Posted by Ostinato

I recently purchased a 10hp electric start outboard because I injured my shoulder. I need to buy a battery for it and the manufacturer claims it needs only 40-70 cold cranking amps. Car batteries look like over kill.

Has anyone had any experience using motorcycle batteries?

garden tractor battery at autozone, the cheap one doesn't have much lead in it, and is pretty light.

I would suggest you use some A123 M1 26650 LiFeCo cells, 4 in series, it would weight about 1lb. I made one for my MG Midget as the starting battery (used 12 4x3 so more capacity)

A123 Worlds Smallest VS. "Strongest" 12V Jumpstart battery - YouTube

[David M]

Motorcycle batteries can start 1200cc motorcycle engines. That is a lot more engine displacement than a 10 horsepower outboard engine. I know it's a bit late to be saying this.

[deckofficer]

This 15 lb Odyssey battery has 680 cranking amps, can be deep cycled, and cranks a Dart 427 cid engine in my hot rod. Model number PC680, dry paste electrolyte so no terminal corrosion or acid spills. Has been starting the hot rod for 17 years and has a low self discharge so doesn't need a charge after sitting for the winter. 16 a-hr.