Battery failure Options

[slivel]

Wife and I took the 914 to a cars and coffee (about 20 miles away) yesterday morning. Everything seemed normal except that we started noticing a strange odor on the way home. Just a few blocks from home the engine quit. I managed to get it running, although poorly and got it home. The first thing I checked was the battery. The case was bulging and too hot to handle. It was also outgassing vapor. This is a one-year-old AGM battery.

I got it exchanged for a new one at no cost to me but the experience was unnerving.

I suppose that I now have to be certain that my charging system did not contribute to or cause this battery failure.

Has anyone experienced this sort of battery failure? It must have been some internal short to have such a rapid decline. I really was concerned that the battery would rupture.

The chemical vapors left a coating all over the engine compartment/trunk area. Are there any good ways to neutralize the acid residue?

Thanks.

[NARP74]

What battery? My experience with batteries over the last few years has not been good. Not the same as yours but I don't get more than three years out of them anymore. Duracell AGM from a shopping club.

[rick 918-S]

There is likely a baking soda solution you could buy buy you could also make some up. I would really be concerned about what was left behind. That stuff has killed so many 914's we cant count them all. Your alternator or voltage regulator is likely fried check all the wiring for overheating as well. Maybe the grommets through the rear engine tin is missing causing a short. Glad you stopped.in time to save the car.

[slivel]

There is likely a baking soda solution you could buy buy you could also make some up. I would really be concerned about what was left behind. That stuff has killed so many 914's we cant count them all. Your alternator or voltage regulator is likely fried check all the wiring for overheating as well. Maybe the grommets through the rear engine tin is missing causing a short. Glad you stopped.in time to save the car.

I made a solution of household ammonia and water and wiped the area down. My thinking is that ammonia is alkaline which should neutralize the acid residue. But maybe my recall of chem is faulty. Way back when I was a kid working at a gas station, the old hands would pour coca cola on corroded battery trays and it worked somehow. Coke contains phosphoric acid, so it is a mystery.

I'll checkout the wiring and bulkhead passthrough's for shorts. My battery is actually in the trunk and not in the normal 914 location. Next will be a baking soda wash. Then clean and apply rust reformer and paint. I hope the alternator/VR are OK.

My plan is to check the wiring, install the new battery, start it up and check the gauges for abnormalities and the exposed wiring for heat.

[porschetub]

I would suggest that the VR has failed and the battery has overcharged, the OP is lucky the battery didn't blow ,up appears it was close to it .
Not likely the battery was faulty so a full cleanup is required in the enginebay followed by a test to check input voltage @ the battery , don't proceed further if the voltage is over 14.4V (no load) .
Don't continue using the car till you have tested otherwise you may have a repeat issue with a possible worse outcome ,good luck and report back, cheers.

[brant]

Do you mind sharing the brand of battery?

[GregAmy]

Have you measured voltage when running?