My car's been struggling to start in the cold this week, so I thought I'd give the battery a check.

It's not the original and is marked 'Maintenance Free', but it has the removable screw caps. I've taken them off and there is no liquid inside. Should there be?

Can I just cover the cells and recharge or is it supposed to be dry? There is no level marking on the outside.

Many thanks.

Mark

 

It should be topped up just over the cells! Use de-iornised water. But to be fair, if its been dry a while its probably killed it! Go get yourself a new battery it'll save you hassel when your parked in the middle of no where and the battery is flat!

 

Cheers, bud. I'll try to revive it to last the rest of the week and get a new one at the weekend.

 

if its that low then de-ionised water alone wont revive it you need some battery acid. de-ionised water is only for minor top ups.

 

A 100% test can be done using a multi-metre

You need to have a minimum static voltage of 12.2volts. With no surface charge so switch the headlights on breifly to remove any before you start the test.

Then disconect something to stop the engine from starting. Crank sensor is probably best.

Then crank the engine watching the metre> You should be able to crank the engine for 15 seconds without the voltage dropping below 9 volts.

If it drops at all below 9 volts within the 15 seconds the battery has had it.