Amperage for Charging Batteries

[thebird00]

I had an alternator go out and it drained both my batteries. I have a charger at home. It has a Maintain, 10 Amp, and 40 Amp setting. I have heard it is best to slow charge dead batteries.

Does anyone have a guess at the amperage for the Maintain setting? I'm figuring 2 Amp. Also how long should I charge the battery if it's 2 Amp?

Thanks for any help.

 

[pauly383]

At 2 amp its going to take awhile . At 6 amps ( my charger at home ) I can start the charge in the morning , do all my yard work , play with the truck awhile , and it starts when I am done in late afternoon .

 

[4X4HIGH]

It is best to charge at 2 amps for however long it takes especially since the batteries are drained. Oh, you can also charge both batteries at the same time. Also sometimes if the battery is so low on charge the charger may not want to start charging at 2 amps, in this case hook up a good battery like you would when jumping a battery and this will trick the charger to start charging at 2 amps.

 

[thebird00]

I started charging one last night around 6pm. Is 24 hours enough at 2 amp or should I just add the second battery to it tonight and charge both?

4X4HIGH, can the battery over charge or will the two batteries just equal themselves out if charged together?

 

[thebird00]

Anybody know a good way to test the charge on the battery? I assume you need to put some type of load on it.

 

[tRustyK5]

http://www.solarseller.com/battery_state_of_charge_charts.htm

A voltage test will give you a good idea of battery condition. If you click the link and scroll down just a hair you'll see a chart...

Rene

 

[thebird00]

Thanks, thats good info.

Does anyone have an idea how many amps that charger is putting out when it's set on Maintain. I'm guessing 2 amps.

 

[pauly383]

If it doesn't have a meter you can use an find an old amp gauge on any old car ( or those 10 dollar 3 gauge sets at Harbor Freight ) and use it , it goes in series on positive wire , and you can cut a hole in charger case if you have room .

Or just use a clamp over meter with dc amps included and measure it .