Battery Charger Boiled my battery!!

Bondad · 01-04-2012, 02:32 PM

I was given a used battery charger/maintainer for Christmas. It has a setting for Deep Cycle or Starter battery and can be set to 50 amps(?) for a quick boost to a starting battery, 15 amps for charging a 12V battery or 2 amps to maintain a 12V battery. After it charges it is supposed to automatically switch to maintain mode and apply 2 amps as needed.

I hooked it up to my house battery on the 15 amp setting and the meter went to 75%. So far so good. After about 48 hours it was still at 75% and the battery was warm (not hot) but when I felt it I heard the battery boiling.

The charger IS used but it shouldn't boil the battery when it's at 75% should it? I'm trying to figure out if the charger is malfunctioning or if it was due to a bad battery or ??

FYI - I had planned to replace this one with two 6ers from Costco in the spring but wanted to it for two weekend winter trips in January and February.

wardy · 01-04-2012, 03:11 PM

Sounds like you have an "aged" battery with plenty of internal resistance. I also have the type charger you describe. On older batteries I must stop the charger manually but on batteries in good condition it works well.

Bondad · 01-04-2012, 03:53 PM

Quote:

Originally Posted by wardy

Sounds like you have an "aged" battery with plenty of internal resistance. I also have the type charger you describe. On older batteries I must stop the charger manually but on batteries in good condition it works well.

In the future (and on different batteries) at what point would I manually stop the charger? It never went above 75%. Do I just time it for x number of hours depending on the battery size or ?

wardy · 01-04-2012, 04:02 PM

As soon as the boiling starts I think you have reached the current capacity of that battery. If you're not able to supervise the process then set the charge at it's lowest rate (typically 2 amps). I've managed to use a Trojan battery for 3 years (extra) like this. I bet you could make it to the spring if you're okay with a diminished but still useful charge.

wa8yxm · 01-04-2012, 06:13 PM

sounds like your free cgarger needs some adjustment.. alas, sometimes they do.

Ed-Sommers · 01-05-2012, 09:16 AM

It's a bad battery.

Ed

freebirdbus · 01-05-2012, 09:49 AM

"The data supports no conclusion at this time"

It sounds like you have a used charger and a used battery. Lots of potential unknowns with both. A pad of paper, pen or pencil, a digital Volt-Ohm meter, and a battery hydrometer will all help you past the unknowns and give you a solid diagnostic basis to make a good decision about where you are and what your options will be. You can check each of the battery's cells with the hydrometer and the VOM for voltage, before and after charging as a good foundation. I would be happy to help you further once you have some readings.

hamguy · 01-05-2012, 10:45 AM

Quote:

Originally Posted by Bondad

The charger IS used but it shouldn't boil the battery when it's at 75% should it? I'm trying to figure out if the charger is malfunctioning or if it was due to a bad battery or ??

Take it to an Interstate Battery dealer or some reputable battery dealer. Have them load test all of the batteries, then replace the house batts and learn how to use the charger (if you have the manual). You can get a manual on line if you know the model/manufacturer.

Bondad · 01-05-2012, 04:18 PM

Quote:

Originally Posted by hamguy

Take it to an Interstate Battery dealer or some reputable battery dealer. Have them load test all of the batteries, then replace the house batts and learn how to use the charger (if you have the manual). You can get a manual on line if you know the model/manufacturer.

Thanks Hamguy. I will take it (It's just one)and have it load tested as you suggested. I do know how to use the charger. It came with the manual and I read it three times before attempting anything. According to the manual, once it detects a 100% charge it auto switches to naintain mode but this battery never hit 100%.

To add to the fun, I discovered late last night when I moved the battery that I've got battery water on my stick and brick basement floor that needs to be neutralized tonight.

smiller · 01-05-2012, 06:03 PM

It could be the battery or the charger but it should be noted that modern microprocessor-controlled chargers are very good at detecting problems and usually will not boil a battery like that no matter what. Inexpensive chargers can be very expensive when you take the cost of batteries into account.