Citroen Xantia Turbo Diesel 1.9l - Sealed-for-life battey - Dave Bham

A new (6 months old) battery twice failed to provide enough power to start the car when it was very hot. The first time was when I had filled up after 2 hours of towing a caravan, - on a hot day. Eventually battery recovered enough to start after disconnecting caravan electrics and waiting for 2 hours. The 2nd time the car was solo. Started OK when cold and ran 10 miles to a lunch. After lunch ran 7 miles to the supemarket near Rouen on a very hot day (car in full sun), did about an hour's shopping - battery only just able to turn engine over very slowly but not enough to start the engine. Battery checked with an avometer after it failed to start the engine - down to about 11 volts Bought new battery in the supermarket - no further problems even though weather continued hot.

Does anyone have any idea of why the battery failed? Is there any history of sealed-for-life batteries being susceptible to high temperatures ( the bonnet & engine bay seemed very hot when I opened up to check the battery)?

Citroen Xantia Turbo Diesel 1.9l - Sealed-for-life battey - Peter.N.

The only thing that will actually cause a battery to fail is continual deep cycling, the battery being frequently charged and fully discharged, car batteries are not designed for this. The only other cause would be a fault in manufacture.

Are you sre the battery is being fully charged? you should have about 14 volts across it with the engine running, any less and it won't fully charge, much more and that will also damage the battery by drying out the electrolyte and possibly buckling the plates as it will get hot. The voltage should be withing the range of 13.8 - 14.4.

Citroen Xantia Turbo Diesel 1.9l - Sealed-for-life battey - Collos25

When towing have you the fridge switched on if so the battery you have is probably not large enough for the job in hand .