# How long to recharge deep cycle battery?



## Silvercreek Farmer

I have a one year old Marine Deep Cycle/Starting Battery that I use for my Trolling motor and to jumpstart my garden tractor. Two days ago it was low so I put the charger on it (2 amps) for 24 hours. The "Charged" light was still off after 24 hours and it looked like it was still drawing around 3 amps. I unhooked the charger because I didn't want to over charge the battery. Should I put it back on and just wait until the light comes on? Will it drop to 0 amps when it is fully charged? The charger was set on Automatic Deep Cycle charge setting.


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## Guest

I have a deep cycle battery that I use on the camper. One day last summer it wouldn't charge. I put it in the basement so it wouldn't freeze. I was saving it so I could trade it in (core charge) for a new one. This spring I was trying to charge a different battery and it would not charge up. I bought a new battery charger and charged the battery from this spring. I thought I would try it on the deep cycle because the old battery charger was bad. I hooked it on and it took 3 days to charge the deep cycle. I think it was running at 10 amps and it has a special setting for deep cycle batteries. The new charger paid for itself by rerviving the deep cycle. If your charger has charged your deep cycle in the past then carry on.


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## Bearfootfarm

I'd leave it on longer.

Deep cycle batteries can take a *long* time to fully recharge, especially with a low amp charger.


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## radiofish

Depending on the physical size, a "deep cycle' battery may have 80+ "amp hours" (1 amp per hour at 80 hours) of storage capacity. So to charge a deep cycle battery at 2 amps from a "discharged state", would take around a couple of days (48 hours).

So by your using 2 amps at 24 hours on a 'low current' battery charger - would give you a charge time of 48 'amp hours'. If you have one handy, a volt meter to monitor the 'charged' battery voltage would help to indicate the state of the charged battery. From before when you hook up the charger, till the time that you turn it off.


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## Guest

I don't know how accurate they are but I have one of those little floating balls type battery tester . If I remember correctly it has 5 balls & 4 balls floating is a full charge & 5 balls floating is overcharged . It's very similar to the little floating balls type antifreeze testers . I would assume most auto parts stores & probably wal mart has them .


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## roachhill

I found a nice Vector computer controlled battery charger that seems to do a good job controlling the charge level. I charge my batteries at 40 amps and it still can take a good portion of the day to charge (although I have 450 amp hour capacity) The computer will slowly run the amps up to 40 then hold it there until the batteries are mostly charged then lower the amps little by little to top off the charge. By the way if you want your battery to last try not to let it get to low before getting it on the charger.


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## ace admirer

if its a 800 ah battery and is 50% discharged (400 ah) and it is charged at at rate of ten amps,,,then it would take about 40 hours of charge.....basically....as othes have pointed a hydrometer is a good method to determine charge (if electrolite mixture is correct and access to electrolite is available....a lot of batteries are sealed these days)

remember most batteries will loose 10% of charge per month idle time,,,,,in 5 months , a battery would be 50% charged and already damaged.....


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## Silvercreek Farmer

Cool, thanks guys, I will plug it back up!


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## Harry Chickpea

VW Hillbilly has the right idea. The best way to verify a charge is through a specific gravity tester. Charge readings can be deceptive.


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## Nevada

Silvercreek Farmer said:


> Should I put it back on and just wait until the light comes on? Will it drop to 0 amps when it is fully charged? The charger was set on Automatic Deep Cycle charge setting.


If you have a light that indicates when the battery is fully charged then you can be sure that the charger will cut out. I know that mine does.


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