Thread: Exploding Battery

I used to heat shrink my spanners etc when working on live systems. DC but not cars.
Can also buy insulated ones but overkill for what we were doing.

Originally Posted by rijidij

The Exide guys said, always undo the earth first to remove a battery, and connect the earth last to fit one.........and watch where you stick your spanner.

Murray

Hi Murray, that’s good advice and standard practice is when working on a vehicle with a single battery, the negative lead is the first lead to be removed before you start to work and once finished, the negative lead is the last to be reconnected.

On a vehicle with multiple batteries, it is recommended that the negative lead on ALL batteries be removed first and then the positive lead of the battery you are going to work on can be removed safely.

The reason for removing all negative leads is because most dual battery controllers do not isolate immediately after the ignition is turned off so even though you have disconnected the negative lead from the battery you are going to work on, if anything bridges that battery’s positive lead to earth, there can still be damage caused because the other battery(s) is still live.

Just a minor amplification to Drivesafe's excellent advice. Disconnect the earth lead from the battery first - this is not always the negative; any pre-67 Landrover is positive earth (originally anyway).

If you think about it for a moment, when working on the earthed pole of the battery, accidentally shorting it to earth will not cause any problem - and once it is disconnected, shorting the other terminal to earth won't either.

In the reported incident, the battery, presumably having just been charged, had some hydrogen in the air above it and in the space above the electrolyte. This is quite common to be emitted while charging, but since a hydrogen/air mix will ignite over a very wide range of concentrations, any spark near a lead acid battery is potentially very dangerous, particularly since an explosion in the battery itself is likely to spread acid everywhere.

John

Originally Posted by JDNSW

In the reported incident, the battery, presumably having just been charged, had some hydrogen in the air above it and in the space above the electrolyte. This is quite common to be emitted while charging
John

Another reason why I love my Optima's. AGM is so much safer, and no corrosion on terminals, leads or battery trays.

Rob W