GATE BATTERIES

[Builder]

Anybody know if the gate batteries used in the Liftmaster, Might Mule, etc. gate openers are rechargeable like a car battery would be? Customer has a gate I installed about 8 months ago that is battery powered with small AC/DC charger plugged into outlet at the base of a lamp post nearby.
Unknowingly, the GFI on the outlet tripped. Gate batteries went dead before customer realized GFI tripped. Bought new batteries to get him up and running. Are the old batteries toast or can they be recharged?

 

[Ken]

Anybody know if the gate batteries used in the Liftmaster, Might Mule, etc. gate openers are rechargeable like a car battery would be? Customer has a gate I installed about 8 months ago that is battery powered with small AC/DC charger plugged into outlet at the base of a lamp post nearby.
Unknowingly, the GFI on the outlet tripped. Gate batteries went dead before customer realized GFI tripped. Bought new batteries to get him up and running. Are the old batteries toast or can they be recharged?

I see solar cells on the gate posts in several areas. and are these not the same as battery used in safety exit lights large flash lights. 2x4 x6" tall 12 volt
I wouldn't put on high current charge but low charge should work.
GFI will trip due to moisture if outside exposed. voltage spikes
ken

 

[Builder]

I see solar cells on the gate posts in several areas. and are these not the same as battery used in safety exit lights large flash lights. 2x4 x6" tall 12 volt
I wouldn't put on high current charge but low charge should work.
GFI will trip due to moisture if outside exposed. voltage spikes
ken

Here's the battery I speak of: FM150 12 VOLT MIGHTY MULE GATE OPENER BATTERY FM500 502 on eBay!

When I try to charge the dead battery, the battery charger indicates "charged"

I do know what you mean about GFI circuits being used outside. Moisture wreaks havoc on them.

 

[Ken]

Here's the battery I speak of: FM150 12 VOLT MIGHTY MULE GATE OPENER BATTERY FM500 502 on eBay!

When I try to charge the dead battery, the battery charger indicates "charged"

I do know what you mean about GFI circuits being used outside. Moisture wreaks havoc on them.

O'k do you have a dc volt meter and put leads across the battery should read 12 + volts then apply charger should increase above unloaded level. some chargers measure the amperage to indicate when charged if your charger is lower voltage would indicate a charged battery.
Does the gate opener work with a lawn mower battery connected by jumper cables. could be a fuse opened when the GFI tripped.
ken

 

[gengine]

Is it possible the battery is frozen? I don't know where 750 mi. east of a *#~*#!% is. A weak battery will freeze, and then won't take a charge. Sometimes you can thaw it out and then put a charger on it. That small of a battery, take it inside for a couple days and then try charging. After freezing, it seems they are never as good as they were. I wouldn't recommend any higher than 2amps, any more can get that battery pretty hot, and possibly cause a fire or explosion. If it's not froze, and the charger says charged, I am sure the battery has gone bad.

 

[Builder]

Is it possible the battery is frozen? I don't know where 750 mi. east of a *#~*#!% is. A weak battery will freeze, and then won't take a charge. Sometimes you can thaw it out and then put a charger on it. That small of a battery, take it inside for a couple days and then try charging. After freezing, it seems they are never as good as they were. I wouldn't recommend any higher than 2amps, any more can get that battery pretty hot, and possibly cause a fire or explosion. If it's not froze, and the charger says charged, I am sure the battery has gone bad.

I connected a very small trickle type charger to it and it quickly reads "charged".

 

[Ken]

I connected a very small trickle type charger to it and it quickly reads "charged".

try a auto head light across the treminals if bright then it is the gate opener or wiring to it. if dim it is the battery sometimes the cells will swell and then the rivet to attach to next cell is loose enough to measure 12 volts but have no amperage. Maybe try another battery
any 12 volt will do for the test.The battery charger may have tripped the GFI and now is faulty.
Your information says wreasling bears part of you exercise program. There is bears here in Ark.but we leave them alone.
ken

 

[Builder]

try a auto head light across the treminals if bright then it is the gate opener or wiring to it. if dim it is the battery sometimes the cells will swell and then the rivet to attach to next cell is loose enough to measure 12 volts but have no amperage. Maybe try another battery
any 12 volt will do for the test.The battery charger may have tripped the GFI and now is faulty.
Your information says wreasling bears part of you exercise program. There is bears here in Ark.but we leave them alone.
ken

Gate works fine now. Bought new batteries. Just want to know if the batteries I removed can be recharged and used again.

I took a tractor light and put it across terminals. It lit up pretty well. Just dont get why they were dead, left in my garage for 3 months, but read "charged" on battery charger as soon as they were hooked up.

 

[BeezFun]

Anybody know if the gate batteries used in the Liftmaster, Might Mule, etc. gate openers are rechargeable like a car battery would be?

I had a Mighty Mule, the battery is rechargeable but it's not a deep cycle battery. So running it dead causes cumulative damage that will eventually cause it be unable to hold a charge. I would be surprised if one discharge would ruin it unless it was cold out when it happened. A discharged battery will freeze more easily than a charged one, once it freezes it's usually toast.

 

[Builder]

I had a Mighty Mule, the battery is rechargeable but it's not a deep cycle battery. So running it dead causes cumulative damage that will eventually cause it be unable to hold a charge. I would be surprised if one discharge would ruin it unless it was cold out when it happened. A discharged battery will freeze more easily than a charged one, once it freezes it's usually toast.

I think that's what happened. The batteries were discharged back in January when it was below freezing.