"Andrew Gabriel" wrote in message ...

In article ,
"Norbert Thistlethwaite" writes:


I bought a Clarke 910 jumper/compressor, after about 2 years, I was
unable
to charge the unit.

Lead Acid batteries need care.
Stick one on the shelf for 2 years, and it will likely be
dead, especially if it wasn't fully charged to start with.
I always try to recharge mine as soon as possible after use.
Flattening one is bad news too, for its longevity.
You need to periodically top it up, but overcharging (as
some of the cheap chargers which come with these can easily
do) will also wreck a SLA battery. I usually charge mine
from an accurate voltage and current limited bench supply,
and never used the wallwart which came with it and has no
voltage or current limiting (other than its own internal
resistance). Some come with crap batteries, as I said.

The jumper had good use for the first 12 months and was regularly charged.
When the old car was replaced, the Clarke 910 was little used.

It was only used for the occasional tyre topping up. Maybe the
battery-condition gauge was faulty and tyre use was a greater drain than
indicated.