Charging Maplin power tanks

[Andrew*]

I've got a Halfords automatic car battery charger with croc clips, which I've been using to keep my power tanks full of juice.

Clamped black-black, red-red, switched on the power, and it flashed "charging" for a second then went over to "ready and maintaining". I know for a fact that battery is not fully charged.

I had the switch on "sealed battery" as opposed to standard - would that be correct?

There's loads of some kind of deposit on the charger terminals. Might this be the problem, causing too much resistance?

Any advice appreciated!

Andrew

[Naz]

Is the stuff on the terminals the same as you get on car batteries Andrew? You can try scraping it of and getting back to clean metal and see what happens. If that doesn't work your battery may be finished, unfortunately they have a limited life. Do you have a test meter or know anyone with one? You could try measuring the voltage of the battery with charger disconnected and then with it connected. Also you could see what the current is when charging.

Archie

[MikeP]

Andrew,

I bought a Maplin jump start, tyre inflating yellow thing - I assume that is what you are referring to. Since it worked well, I bought a second one, but they sent two rather than one. It was my intention to send one back (honest) but I found that one of the new ones behaved exactly as you described.

Kai had recommended the Optimate battery charger and also pointed out that he had removed the battery from the yellow case since it took up a lot less space. I copied him and can confirm that the Optimate works a treat with the two "good" batteries, but even it could not resurrect the bad one that has gone to the great junk yard in the sky.

Hopefully not, but your power tank may have to make the same journey.

Mike

[barkis]

Andrew, do you have a voltmeter DC? If yes, connect it across the terminals of the suspect battery, The voltage should read between 11 and 13volt. If you put a load of some sort on the battery, and watch the reading,. If it collapses altogether, I would reckon one of the links inside has gone bad. The battery is made up of 1.5v cells and joined together internally. One of the links could have collapsed due to the initial switch on. Hence the high reading, then nothing.

The gunge on the terminals is electrolosys a verdigris coloured crystaline that builds up on lead acid batteries if not cleaned regularly. The same thing attacks the internal links and one day, dead.

A long speech to say I think it is probably knackered mate.