Battery Blowing Up

[das boots]

Not ZHP. But a BMW. This is for my E30 M3. If out of topic, please delete.

To all battery gurus and others.


Did one crank this morning for my bi-monthly ride. Turn ignition On and I heard a THUD. Then no more crank for the second try.

Opened up trunk and I see smoke and smell electrical short. Opened the battery tray cover and all of the battery water are spilled all over and down to the holding tray and void. All battery water. Took everything apart and cleaned and rinse all chemicals.

Battery since 2016. And always on battery tender when not in use. Battery tender was unhooked when I initially started the car.

How does a battery blow up? low out was from both Positive and Negative side. And Inspection covers all popped. So got another from O'Reilly's.

Thanks.

[cakM3]

I have never seen a battery do that in a car but then I tend to change out my batteries within 5 years.

[John in VA]

Overcharging is one of the main causes of battery swelling. Overcharging is usually from a bad voltage regulator. You need a charging system test before the new battery gets damaged. https://micdot.com/car-battery-bulge/

[das boots]

Would trickle charging be considered overcharging? Battery was purchased in 2016. Over 8 yrs. Battery rarely used since the M3 is a garage queen. Used twice a month only. Nice article. Thanks @John in VA.

[cakM3]

Would trickle charging be considered overcharging? Battery was purchased in 2016. Over 8 yrs. Battery rarely used since the M3 is a garage queen. Used twice a month only. Nice article. Thanks @John in VA.

I would say it depends on the brand of trickle charger/battery tender you are using. I have been using the CTek battery tender on my Porsche and M3 for years and have not had any issues with the battery in either car. Since Porsche sells CTek battery tenders under the Porsche name I figured having CTek battery tenders to keep the battery charged in both cars is good enough.

[BADCLOWN]

I’m not by any means extremely knowledgeable on car stuff but I’ve never seen a battery do that either. That’s pretty wild, glad nothing more serious happened to the car

[das boots]

Battery tender is a BMW cigarette lighter plug in type. Maybe learned a lesson not to leave charger plugged in all the time?

Never happened before on previous battery with plug in trickle charge. E30 M3 does not have the Positive terminal under the hood unlike the E46.

I use the C-Tek charger on my E39 530i with direct wiring to the battery terminals in the trunk.

I also use another BMW charger for the ZHP with hook ups in the hood.

[wstr75]

I had a battery explode like that many years ago. It was a cold day and I had tried starting the car until the battery got weak. I hooked up the jumper cables and let the battery quickly charge. It was when I took the cable off that it exploded because of the jumper cable spark that happened when taking a live cable off. I now know to always remove the cable from the car providing the power first. Charging creates hydrogen gas. This link explains: https://www.offroadxtreme.com/tech/w...ith-a-battery/

[das boots]

Direct short inside the plates.

[racer2086]

I JUST had this happen to me last Thursday in my 1985 Mustang. It was on a NoCo Genius 1 tender for about 6 weeks. I removed the charger and it exploded blowing the top off the battery when I went to start the car. In the process of RMAing the charger. Boy did it make a mess though with acid everywhere. What kind of charger were you using?