Battery Charging

kuchengj

Recruit
Joined
Jun 23, 2004
Messages
5
I have a Sears 10 amp charger with regular and deep cycle modes, 2 and 10 amp settings.
How should I charge my starting battery? Trolling motor battery?
 

halas

Petty Officer 1st Class
Joined
Jan 27, 2009
Messages
347
Re: Battery Charging

Charge it with 2 Amp setting if you have time, 10 Amp if in a hurry. You can charge the batteries trough an accessory plug like cigarette lighter or trolling motor plug. Assuming that you have selecting switch for your batteries.
I charge mine with the selector switch on "All" trough a cigarette lighter with "regular? setting on the charger.
If you are concerned you could charge with the ?deep cycle? setting with the selector switch on the #2 or deep cycle battery.
When done, switch to #1 or starting battery and switch the charger to "regular" mode to get to the starting battery.
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: Battery Charging

Put it on the 10 amp setting and forget the 2 amp setting. 2 amps is for lawn mowers and motorcycles. The longer your battery is discharged the more damage that will be done. Now tell us what type charger it is. Is it a smart or automatic charger? If it is then watch the guage and after it drops to zero leave it for a couple more hours and then turn it off and disconnect.

Think about the batteries you have and how they are charged.
Example My boat has a group 24 starting battery and a group 24 deep cycle they are both charged with a 65 amp alternator thru a battery isolator on my I/O.
My cars have 100 amp alternators and my truck has a 130 amp alternator.
I have never had any battery that did not last at least 6 years.
Good alternators and smart or automatic battery chargers will control the voltage put out. Most will charge in the 13.8 to 14.8 volt range. Then the battery it self will determine how many amps it takes.

In the case of a 10 amp automatic charger or smart charger on a discharged battery it will start out near 10 amps. As the battery charges the current will continue to drop and most after 2 hours will be 5 amps or less. Even with a 10 amp automatic charger on a group 27 trolling motor battery after a day of fishing it will take more than 12 hours to charge.

If the charger is a manual charger then really need a volt meter to monitor it with.
Manual charger and most trickle charger will over charge because they have no voltage regulator and the voltage can clime way over 14.8 volts.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Battery Charging

Batteries can be safely charged at up to 20% of their AHr capacity. 100 AH battery = 20 charge rate. Going over that periodically as might happen with a high output alternator is of no consequence. Your starting battery rarely gets discharged far enough to require that sort of charge rate. The trolling motor is another matter in that they can be deeply discharged. Your 10 Amp charger will do the job nicely at 10 amps. In fact most on-board chargers for deep cycle batteriesw are in the 10 - 15A range. Charge rates in the 2A range are almost in the "maintenance" charge range. Deeply discharged batteries should be charged as quickly as possible as they do not like to be left in a discharged state. So charge the batteries at the end of the day. Not a matter of hours before you head out for a trip.
 
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