Can anyone explain…

[LittleBlackMule]

.. why a leisure battery I use for my fence is showing fully charged when tested, yet the energiser ‘low battery’ light flashes as soon as it’s attached?

I’ve put the battery on charge to make sure, and it’s definitely 100%

 

[PeterNatt]

Faulty connection. Clean battery terminals and connection clip with wire wool or sandpaper and also check there are no breaks in the wires.

 

[LittleBlackMule]

Faulty connection. Clean battery terminals and connection clip with wire wool or sandpaper and also check there are no breaks in the wires.

The battery terminals are clean.
The energiser works fine with my other identical battery.

Is there something that can prevent a battery from discharging?

 

[marmalade76]

One tip I only heard of fairly recently was that you need to keep the earth damp as it makes it work better - worth a try

 

[Britestar]

One tip I only heard of fairly recently was that you need to keep the earth damp as it makes it work better - worth a try

Yes, I poured a bucket of water around my earth today

 

[little_critter]

I’ve had this with leisure batteries in the past when they’ve got too flat. They just won’t take charge. The charger says full but then it just won’t hold the charge.

 

[PurBee]

Unfortunately there are some crap quality batteries on the market, that still cost the same as good ones, and they easily ‘fry’ with charging cycles. Use them a few months and they start to get really quick to discharge and they also charge to ‘full’ very quickly too, but they dont hold the charge, and as soon as theyre disconnected from the charger, they’ll be at 3 volts of something.

How are you measuring the ‘fully charged‘ status? With your battery charger saying its full or with a multimeter on the battery terminals?

 

[ycbm]

OH says buy a volt meter (apparently cheap and readily available) and if the volt metre says less than 12.2 volts when "fully charged", then your battery is ******.

Hope that helps!
.

 

[DabDab]

OH says buy a volt meter (apparently cheap and readily available) and if the volt metre says less than 12.2 volts when "fully charged", then your battery is ******.

Hope that helps!
.

This. Measure the voltage of the actual battery when you take it off the energiser. Batteries can get dirty (for want of a better word) inside over time and they just don't hold a charge for any length of time

 

[LittleBlackMule]

Thank you all.
New battery purchased.

 

[spottypony90]

I have the same issue… my battery is only about 4 months old though and from Halfords! I haven’t tried the earthing trick yet though so will give that one a try.

 

[Melody Grey]

I have the same issue… my battery is only about 4 months old though and from Halfords! I haven’t tried the earthing trick yet though so will give that one a try.

I had a tricky battery that I’d bought from Halfords- they’re covered by a warranty for 12 months, so take it back and get it exchanged if it’s none of the simple fixes outlined above?

 

[spottypony90]

I had a tricky battery that I’d bought from Halfords- they’re covered by a warranty for 12 months, so take it back and get it exchanged if it’s none of the simple fixes outlined above?

Hmm I may have to do just that but I don’t have the receipt and I think I read somewhere that it has to be registered online to be able to be accepted back? Was yours registered?

 

[Melody Grey]

Hmm I may have to do just that but I don’t have the receipt and I think I read somewhere that it has to be registered online to be able to be accepted back? Was yours registered?

No mine wasn’t registered. It was Halfords branded and I either had receipt or showed them the transaction on my bank statement matching the amount. They never questioned it- was a Sunday morning with student staff….probably helped!

 

[Nasicus]

I found for my UPS batteries (big chonky things), that if they got too low, then the 'smarter' battery charger wouldn't charge it, and just say it was full. Volt meter determined that to be a lie. So we used a 'dumb' charger, aka cheap, simple thing to pop it back over the threshold for the smarter charger to recognise it and get going.

 

[expanding_horizon]

I found for my UPS batteries (big chonky things), that if they got too low, then the 'smarter' battery charger wouldn't charge it, and just say it was full. Volt meter determined that to be a lie. So we used a 'dumb' charger, aka cheap, simple thing to pop it back over the threshold for the smarter charger to recognise it and get going.

Can anyone share a link to a “dumb” 12v leisure battery charger? I’d like to try this with 2 potentially dead 12v batteries showing about 8 volts

 

[Carrottom]

I find when charging batteries the charger will have the charged light on after a few hours, but I leave it on and then the charging light comes on again. So I usually leave them on for 24 hours. Seems to work. Our Halford leisure battery is 11 years old, it doesn't stay charged for as long as when new but still lasts a few weeks.