Split Battery

[Guest morganr4]

The battery failed in my 1997 Alhambra last week (can't really grumble - it is the original fitted item). On inspection, the two end panels of the battery have split open, presumably due to internal pressure from swelling plates, or possibly from unvented gas pressure?

 

Any ideas why this should happen? In 35 years of motoring I've never come across this, and am worried that it might be the symptom of a deeper electrical problem (over-voltage charging perhaps?)

 

Has anyone got any ideas? The electrics were performing fine until the failure, and after fitting a new battery today all appears to be OK again (apart from the airbag warning light staying on - any ideas on that?)

[Guest pocketsg]

The battery on my 1997 2.0l actually exploded a year back. This was following the Cat being replaced. When I checked I found that when the cat was failing the back pressure from the exhaust blew off a hose which connects to a steel pipe near the battery compartment. This wasn't spotted and the hot air from the pipe melted a hole in the plastic separater and heated up the battery. Took a couple of weeks!

[seatkid]

Sustained overcharging at high current can heat the battery to the point at which thermal runaway occurs - the battery plates then buckle and the battery can explode or more likely split.

 

Most likely scenario is that one cell failed and shorted internally, leading to overcharging of the remaining cells by the alternator.

 

To be on the safe side however, check the alternator voltage, this should not rise above 14.8 volts (battery fully charged - no load), as it is possible for the voltage regulator to fail and give excessive voltage.

 

If there has been acid spilled, do your best to clean it out as its likely to cause a lot of electrical grief with the wiring under the tray.