Dead Leisure Battery

[Redwing228]

Lead acid batteries

Sorry to say that lead-acid batteries are normally ruined by being run flat. A 12V (six-cell) battery can be considered 'flat' when showing 11.8V when under load, and once completely exhausted are difficult to recover, and to be of any use, a battery in this state must be immediately recharged.

During discharge lead sulphate is formed on both positive and negative plates and gives a high resistance across the whole battery - this is why your electronic chargers don't work in this case. A 'traditional' constant voltage charger of the type shown in the thread may be able to force some current through the battery and recover it. If the charge current stays low and the battery starts gassing prematurely - a sign of full-charge on a healthy battery - then I'm afraid it's time for a new battery.

IMHO so-called leisure batteries are not true 'deep-cycle' but any l-a battery is ruined by being left flat, sorry.

 

[yankeebloke]

JUst thought i would let you all know the results.

Charged the battery at 8 amps, then onto a slower 4 amp charge.

Came home tonight, charger says charge complete, battery at 100% charge.

Disconnected charger and measured battery using multimeter, 12.9 VDC

so looks like its all ok.

Cannot put back on boat until tue next week as am away on business, but will let you know if it works and charges ok on boat as soon as i can test.

 

[VicS]

Disconnected charger and measured battery using multimeter, 12.9 VDC

Check it again after it has rested for 12 hours or so. That will be a more meaningful figure.

Looked in our local Halfrauds toay. They don't have those chargers ... but then if there is only one branch that does not have them it will be ours!

Gosh .. reminds me i put my car battery on charge earlier today. ( Charger similar to Ruffles grandfather's )

 

[Mike2309]

Before this thread is abandoned can I ask if I should bring my 60ah "Leisure" battery home for a mains charge when it drops to 11.8 v on the voltmeter I'm just about to fit? I'm assuming that my 5w solar panel will not be keeping up with the demand from depth/fishfinder, interior lights, nav lights and VHF (no other means of charging)
It's not a huge chore to bring the battery home -the boat is moored about 100 yards away.

 

[VicS]

Before this thread is abandoned can I ask if I should bring my 60ah "Leisure" battery home for a mains charge when it drops to 11.8 v on the voltmeter I'm just about to fit? I'm assuming that my 5w solar panel will not be keeping up with the demand from depth/fishfinder, interior lights, nav lights and VHF (no other means of charging)
It's not a huge chore to bring the battery home -the boat is moored about 100 yards away.

Since fitting my 5 watt solar panel I have not had to bring the battery home for charging.

That said the boat does not get much use so plenty of time for rechaging, but when it is used the Autohelm is in use all the time.

I'd suggest you avoid allowing the rested volts to drop below 12.2 which is about 50%. If that is not sufficient power a larger battery or a true deep cycle battery is called for.

Once you have your voltmeter ( You need a digital one to give the level of precision required for battery monitoring so I hope you are not just fitting an analogue battery condition meter) see how things go. If you need to take it home to charge do so. Personally I was anxious to avoid transferring it to the dinghy, for the 1/2 mile trip to shore.

Still hoping for a final report from Yankeebloke.

 

[Scotty_Tradewind]

Before this thread is abandoned can I ask if I should bring my 60ah "Leisure" battery home for a mains charge when it drops to 11.8 v on the voltmeter I'm just about to fit? I'm assuming that my 5w solar panel will not be keeping up with the demand from depth/fishfinder, interior lights, nav lights and VHF (no other means of charging)
It's not a huge chore to bring the battery home -the boat is moored about 100 yards away.

YES TAKE IT HOME AND CHARGE IT!
From my own experience of having let a new leisure battery go right to zero and it failed to respond to a small charger or my 913 wind generator.
With the 20A charger she charged up over night and is still holding 12.7+ this weekend with the 913 topping her up.
I'm seriously looking at one of the 30W Solara semi flexible solar panels for fitting on the comanionway garage to help keep the batteries topped up for those periods with no wind for days on end.

 

[yankeebloke]

Just thought i would update everyone

the battery when on charge, and did charge up fine, i then disconnected from the charger, and it has been sitting in the garage for a week now.

Just measuerd it and its still sitting at 13.06 volts so it looks like all is well

that charger from halfords did the job

 

[VicS]

Just thought i would update everyone

the battery when on charge, and did charge up fine, i then disconnected from the charger, and it has been sitting in the garage for a week now.

Just measuerd it and its still sitting at 13.06 volts so it looks like all is well

that charger from halfords did the job

>13 volts! Brilliant.

Thanks for letting us know.

 

[Mike2309]

[/QUOTE]I'd suggest you avoid allowing the rested volts to drop below 12.2 which is about 50%. If that is not sufficient power a larger battery or a true deep cycle battery is called for.

Once you have your voltmeter ( You need a digital one to give the level of precision required for battery monitoring so I hope you are not just fitting an analogue battery condition meter)
[/QUOTE]

Okay 12.2v it is then ( it is a digital meter) thanks for that.
Mike

 

[Cari bean Pie rat.]

How to damage a battery

"Sometimes it's necessary to apply a high voltage (22v) low power 500 milliA for an hour or so, to get a battery back into action and capable of taking a normal charge."

Please tell me more about charging a 12 volt battery from a 22 volt source.

I have never heard of this.

 

[KellysEye]

Most batteries sold are cranking batteries for engine starts, thus useless for the type of relatively low level discharge (for a long time) house batteries. The best deep cycle batteries are 6 volt Trojans wired in series to give 12v. If you don't have space for two batteries then I think they also do a 12v version.

 

[rob2]

Looked in our local Halfrauds toay. They don't have those chargers ... but then if there is only one branch that does not have them it will be ours!
QUOTE]

S'funny VicS says he's from Kent, but Halfords in Basingstoke doesn't even stock Hylomar of Hermatite! (Bunch of Merchant Bankers) Fitted the new exhaust gasket dry, in the end.

Life can be hard enough when shops sell what their title suggests! It's getting so you have to mail order everything you used to buy at the corner store.

Rob (in bitchy mood)

 

[david_bagshaw]

"Sometimes it's necessary to apply a high voltage (22v) low power 500 milliA for an hour or so, to get a battery back into action and capable of taking a normal charge."

Please tell me more about charging a 12 volt battery from a 22 volt source.

I have never heard of this.

quite common, particularly with motor bike battery conditioners etc.

the higher voltage is used to bust the sulphate layer.

see optimate site for details