# Is it ok to keep batteries fully charged all the time?



## budgetprepp-n (Apr 7, 2013)

I have a small solar setup that is mostly for emergency back up. I am using 
the standard type deep cycle lead acid batteries. They stay at full charge almost all the time
is this ok or should they be drained a little now and then?


----------



## Montana Rancher (Mar 4, 2013)

I think it would be good to exercise the battery, hook a dc light bulb to it and leave it on, maybe 4 watts like a camper bulb.


----------



## HuntingHawk (Dec 16, 2012)

Shelf life of the batteries will be longer if kept fully charged. But make sure to check the water levels monthly.


----------



## That Prepper Guy (May 7, 2013)

I don't recommend having batteries fully charged forever and ever.

Keep them in a cool place to preserve their life but charging them forever and ever can and will drain the life of the battery itself.


----------



## Moonshinedave (Mar 28, 2013)

Data suggest it's perfectly ok to keep lead acid batteries fully charged all the time. Matter of fact that is the purpose of a trickle charger. Me personally, I'd still probably work'em a little.


----------



## PrepperThyAngus (Sep 30, 2012)

Deep cycle batteries are designed to discharge up to 20% of their capacity. However, most manufacturers recommend periodic discharge of 50%. Deep cycle batteries are not designed to stay charged constantly for long duration's. However, you might not notice a life difference by keeping them trickle charged.


----------



## Desert Marine (Nov 20, 2012)

I live off-gird and it is common knowledge as well as recommended to have your battery bank at float status whenever possible. That's what charge controllers are designed to do i.e. to charge a battery bank and then keep it at a float status without overcharging it. Many Home Battery Banks Systems which do not use solar panels and charge controllers can do the same i.e. keep their battery banks at float status by using a 3 or 4 stage battery charger.


----------



## paraquack (Mar 1, 2013)

I'll second Desert Marine's post.


----------



## exmilitary (Jun 17, 2013)

I agree with desert marine. Yes deep cycle batteries can be discharged to 20% but they say you should charge it up asap to prevent the plates from sulfating and thus exetending the life of the batteries 
Keep an eye on water levels as well. 
Keep them on a trickle charger.


----------



## PaulS (Mar 11, 2013)

Any lead acid battery that is exposed to air, or left in a discharged state for any length of time will suffer from non-reversible sulfation.

Some notes on electrolyte levels. The "water" level in a lead acid battery drops as the battery discharges. It should ALWAYS cover the top of the plates.
Never fill a battery in a discharged state - charge it first and then fill to the proper level.
Use distilled water (or water that is free of metal salts (well water is rarely good enough)) to fill the charged battery after it has rested.
The cycle goes like this:
discharge for 6 hours, charge for eight hours, rest for eight hours. Fill and clean the battery, test cell voltage levels individually, equalize the charge when necessary. Any cell that is habitually low on voltage over a period of time is problematic and will cause failure of the battery or bank of batteries it is connected to. Replace it before it fails or you will be replacing all your batteries.


----------

