Went to start, and loud pop sound from car

Hello out there. Anyone else have this happen? Went to start the car, a 2001 example, and there was loud ‘pop’ and then nothing. I opened the boot, and there was this smoke smell, along with the battery acid smell. The charger had been on the car to maintain the battery, but it did not keep the battery up. Voltmeter showed 9.5 volts, and the trunk lights were flashing. Now everything is out, no juice. May need new battery, but the pop, like a fuse or something is worry some. I can understand popping a fuse with an overload, but that cannot be the case.

Replace the battery and try again. The pop may have been one of the cells.

The battery just came apart when we examined it. Some of the casing on both sides just broke away in pieces. Messy situation, and a box of baking soda neutralized the spilled acid. Turns out, there are drain holes in the boot floor, as Jaguar anticipated the boot seal leaking and they would be necessary. New battery, and car started right up. There was a notation in the boot area, saying to re-teach the electric windows, but on putting the top up, they worked fine, as I left the car out so as to dry. The ‘reteach’ may have something to do with the side glass lowering to clear the top seal? THANKS FOR THE ADVICE, although my son was over and saw the battery before I did. He has a parts store and went for a new battery and will replace mine under warranty. I now think that I am partially at fault with leaving a trickle charger on the car, as it sits most of the time, but my impression was that its job was just to keep the battery up, and not ‘overcharge’ it?

I question the value of these battery maintainers. I have, over the years, had cars and trucks that were rarely driven and they always started up, even in winter, without reliance on a battery maintainer. I think a good battery is your best insurance.

If the unit you have is really a “trickle charger” and not a battery maintainer, it’s not a big surprise that it cooked the battery. A trickle charger feeds a constant charge to the battery whether it needs it or not - over time, it can kill the battery. A “battery maintainer” shuts itself off when the battery reaches a certain charge level then turns on when it drops below that level.

Vintage cars may not need a battery maintainer for months of storage, but any modern car with a computer controlled engine or always-on accessories like an alarm need one for prolonged storage. Especially modern Jags (post 86 at least.) Even the huge battery in a X308 XJ or X200 S-type won’t last more than a month or a month and a half without a maintainer (unless the battery is disconnected.)

Every time a lead-acid battery is discharged so low that it won’t start the car, it likely has suffered some damage. Something like 10-15 full dead battery cycles could kill it for good, especially if the discharge is a slow one instead of a heavy draw (a full discharge does some damage either way.)


Is it possible that some hydrogen gas built up and when you went to start it there was a spark causing a small explosion, thusly destroying your battery? I guess anything is possible

My thanks for all the advice, and a new battery has arrived. I learned that a procedure needs to be followed to set things right after a battery exchange. The windows on the convertible need to be re-set, but that ‘re-learn’ is quite easy, as you just move them up and hold for three seconds, then the same for down position. The windows on the convert need to be reset, or you can’t close the doors, and you could break the glass. The computer needs to re-learn too, and you must drive the car for some time to get things back to normal. I printed out some instructions for all this.