Battery question

[breezer]

Hi all, strange one this, wondered if anyone had come across this before...

Ride on lawnmower, not been used for a while (few months) and no sign of life when ignition key turned (to on or to start engine)

Took battery out & charged it on my optimate trickle charger, 48 hours and it's still not charged, so went to put it on ordinary car charger (as it has a needle to show the amount of power in the battery)

Charger is UNPLUGGED and when I connect the leads to the terminals it blows the 15A fuse in the charger.

Put multimeter on posts - 11.5V & 17A (I've since been told I shouldn't check amps using multimeter - but multimeter is fine)

Tried battery back in mower & still no sign of life.

My main concern is why the battery has popped the fuses, and I'm also wondering whether the (more expensive) optimate could have been damaged?

Cheers

Jim

 

[madkayaker]

Sounds like the battery has gone short circuit. What's the acid level like and if you can see how much rubbish is in the bottom. Charger should be fine

 

[rtbcomp]

Charger is UNPLUGGED and when I connect the leads to the terminals it blows the 15A fuse in the charger.

Sounds like you connected the leads the wrong way round or a rectifier/output transistor or whatever in the charger is shorted.

 

[shenion]

Charger is UNPLUGGED and when I connect the leads to the terminals it blows the 15A fuse in the charger.

Sounds like you connected the leads the wrong way round or a rectifier/output transistor or whatever in the charger is shorted.

That or you connected the trickle charger backwards.

When you checked the voltage with a meter did it show the correct polarity.

As far as checking amps with a meter, if the battery was any good it would have fried your meter.

 

[Justme]

As said 17amps from a dead short is really really small fry compared to what a battery is capable of.

 

[breezer]

Terminals were definately the correct way around.

Trickle charger has a dummy light which tells you if the polarity is wrong - so does the other charger come to think of it.

Fluid levels look ok but can't see the bottom very clearly

 

[breezer]

Yep, voltage showed correct polarity on the multimeter

 

[MattF]

Is your charger, (the proper one, not the new piece of 'intelligent' tat), actually showing any output without being connected to a battery? As mentioned previously, it sounds like that one has a fault if it blew the fuse, and the leads were correctly connected.

 

[graffian]

Is your charger (the proper one, not the new piece of 'intelligent' tat)

Not bloody lawnmower time already.. My dad has a ride on and the
clutch was slipping so it barely moved, I promised to get it done
over the winter.

 

[iwoo]

If the trickle charger had been working properly the battery would have been reading >13v , so 11.5v sounds low and the battery may be u/s.