Charging battery with outboard?

[LunkerClassic]

I'm a first-time boat owner and am going camping/fishing for the weekend where there are no outlets to charge my deep-cycle at night. I've been reading that the outboard motor will charge my battery while running. Is this true for all outboards wired for elec. start?

I'm thinking of just using my deep-cylcle for start-up and letting it charge periodically throughout the day. Will this work? If so, ......

How long would I need to run the outboard to keep the battery charged?

Are there other ways to charge a marine battery when outlets are unavailable....excluding generators of course.

I've got an '82 Mercury 50hp.

thanks for any suggestions,
aaron

 

[cougar1985]

Re: Charging battery with outboard?

what else do you use the deepcycle for?my boat battery runs the motor,fishfinder,and stereo.not really understanding your question.your 50 will charge the battery,also why not buy a solar charger like i did ,i hook it up when ever im not using the boat or even if im trolling slow .ive never had to charge a battery yet during the season once it was done at the first.

 

[Silvertip]

Re: Charging battery with outboard?

First -- if your engine is electric start, it will charge the starting battery. The engine can also charge a deep cycle battery but depending on its alternator output, you may need to run wide open for hours to put any significant charge on it after a full day of fishing. You also run the risk of discharging the battery to the point where it won't start the engine. Solar chargers are equally inefficient unless you get a big one which would cost a bundle and take up a great deal of space. Small units are well under 1A output and would have to run for days to re-charge a deeply discharged battery. You can use a pair of jumper cables and charge the deep cycle from your car alternator. Most newer vehicles have 100+ amp alternators and do a good job even at idle.

 

[LunkerClassic]

Re: Charging battery with outboard?

Thanks for the advice. I'll probably keep my cranking battery hooked up to the motor and just use my deep cylcle for trolling. Will the car alternator not damage the marine battery? I've read a lot about using only 3-stage chargers and not much over 15 amps. It seems like 100a would be too much, too fast for a deep-cycle. But then if it my only opportunity to get some real juice, I may have to.

thanks

 

[Silvertip]

Re: Charging battery with outboard?

A battery "accepts" a charge. The charging process does not "force" current into a battery. Besides, an auto/truck alternator does not output 100A at idle. The battery will accept what it needs. Besides, you have no other reasonable option unless you own a small Honda or similar generator. You could take another battery along but it's really not necessary.

 

[ron345]

Re: Charging battery with outboard?

There are onboard chargers that will charge all your deep cycle batteries while you run the outboard. I can give you the web site for one of them if you like.

 

[diaric]

Re: Charging battery with outboard?

charging your deep cycle with jumpers will bring it back up, but won't give it the full proper charge. done it tried it. keeps your trolling motor going when your out in the boonies. deep cycles want a slow trickle charge to get right up to full charge

 

[scrobo]

Re: Charging battery with outboard?

Nice info.

I bought a solar panel that outputs 1.8A. I was hoping it would keep a charge. I only use my battery for starting. So I guess I am in no troulble for losing a charge quickly?

 

[diaric]

Re: Charging battery with outboard?

make sure you have the charging adapter, some panels its a seperate accessory. panels work in reverse and discharge your battery in the dark unless you have the add on .