RPM's for Charging Battery?

[boatgrunt]

My two batteries are weak. What RPM do I have to reach for the alternator to charge the batteries and is it safe to run my boat on muffs at that RPM?

Thanks

 

[Don S]

Re: RPM's for Charging Battery?

Get a battery charger.

 

[DukesFin]

Re: RPM's for Charging Battery?

My two batteries are weak. What RPM do I have to reach for the alternator to charge the batteries and is it safe to run my boat on muffs at that RPM?

Thanks

Put it on the water and drive around some. If you can't do that with the power the batteries have, you should pick up a charger if not new batteries anyway.

 

[boatgrunt]

Re: RPM's for Charging Battery?

I have a batter charger but didn't think it could recharge them all the way. I've used my car in the past to jump start the boat. Can the car battery recharge them as well?

 

[QC]

Re: RPM's for Charging Battery?

What's the amp rating of your charger? It should absolutely be able to charge your battery(s) sufficiently. You have that thing so that you don't have to run it or use your car . . .

 

[tommays]

Re: RPM's for Charging Battery?

I have a small old 6/12 volt auto charger that maxs out at 6 amps and has NO problem fully rechargeing a battery overnight

Tommays

 

[vipzach]

Re: RPM's for Charging Battery?

I have a batter charger but didn't think it could recharge them all the way. I've used my car in the past to jump start the boat. Can the car battery recharge them as well?

Even if your charger is just a 12v, 2 amp charger, it will charge your batteries (not 24v right??) It may take it all day if they are really low, but it will do it. This is asuming that there is nothing wrong with the charger.


The car battery, by itself, will only equalize between the three. You could use the jumper cables with the car running, but I think you would need to let it run at a high idle for awhile. Just use the charger!

 

[turbodriven]

Re: RPM's for Charging Battery?

Generally speaking you don't have to rev that high. At idle you should be pushing between 13 and 14 volts. It's best to hook up a multimeter to find out though. The bigger issue is how long it will take to fully recharge a battery at that voltage. I'd recommend what everyone else already has... put it on a trickle charger overnight. You can buy small trickle chargers at Wal Mart for cheap. And they are nice to have.

 

[boatgrunt]

Re: RPM's for Charging Battery?

ok - thanks - i'll use the portable charger.

 

[jastacey]

Re: RPM's for Charging Battery?

It takes about 1500 - 2000 RPM, at a minumim, for the Alt. to really charge a battery and it would take some time ( 3-5 hours ) for the battery to get fully charged, provided the battery isn't sulfated, or otherwise compromised