OK...Heres the scoop. 2 days ago, noticed the battery was hot...as in the sulphuric acid inside was hot! I figured the battery was bad... the current was still good... radio, heater and starter crank well. I replaced it but today the new one has the same problem heating up. Is this a short circuit, missing ground or what? Please guys help me.

Had a Subaru that 'boiled' batteries. Was the alternator - overcharging.
Had battery replaced twice by Sears under warranty, yet they did not diagnose the condition. This could be very dangerous if battery explodes - suggest seeking competent auto electrician pronto.

The place that sold you the battery should have checked the charging system, before they sold you the battery.

Go back to them and have them check the charging system, most likely the voltage regulator is bad and producing greater than 14V
--
'88 240, '92 745, '98 v70 John, Tampa Bay

Check the voltage at the battery terminals when the engine is working (rev it up to 2000 rmp). Most like you'll read high voltage, some 17V. It has to be around 14V.

I had the same problem recently, check this trend:


http://www.brickboard.com/AWD/index.htm?id=882859

When is it getting hot?

If it gets hot while running, is the regulator / alternator screwed up? I would put a voltmeter on it. While running, I would expect it to read somewhere around 13 - 14 volts

If it gets hot while not running, I could only guess a partial short; ie, draining current very fast, but doesn't sound like it's being run down.

Try to give a little more detail on this.

Sorry..let me elaborate then.
I come back to town after a week away, drive around and all I did was replace a blown headlamp bulb. It was then that I notice the battery was emanating a weird smell and liquid seeping out. Figuring it was normal, I drove around but 2 hours later when I rolled down the window had this strong odor...it was still on 2 blocks away so I pull up, pop the hood and voila the battery acid was literally boiling...the covers had popped out as a safet relief and it reeked.
I limped home and the auto store guy was happy to sell me a new one, but that evening when driving around, it happened to slowly heat up and after 20 mins of driving, the battery is literally smoking! I tried turning off the lights, disconnecting fuses, radio, etc but it just heats up when the car is running. It sound bizarre and I dont want my Vovo to go up in flames after the batt explodes in the engine compartment.
I mean the leaking acid already ate out the headlamp adjustment dial and it reeks!
Oh woe is me... this is my 2nd Volvo, but I never have good luck when I buy the same make twice :(

Hi, I've never seen a battery get hot before, are you sure? or are you just assumeing because there are fumes and lots of bubbles comming out? It's almost certain that the alternator regulator has failed, this seems to be a common fault, the symtoms are bubbles and fumes from the battery and bulbs failing.

Thanks a lot man... you definitely pointed me to the right direction...then from there...it was downhill or should I say upwards? I'd already confined myself to go to the repair shop in an hour and pay diagnosis, labor plus spend at least $150 plus for a new one(thats the cheapest of the 3 types), then I figured, duh! I could do this! So I pulled my voltmeter and did the simple test people say should be done and expected to get about 15volts at the terminus given that 13-14.5 is normal. Instead the digital controls shot up at a whopping 19.0- 19.7 volts! I kid you not! This thing was so warped, I only drove down the driveway to try and pry it out and get the right part no. I shall try and replace it and update you guys. I like the support of brickboard...can't beat that!
later all!

I'm not a pro, but I could only guess that something is going on with your alternator (or regulator, if these cars have them). I have a '96 850; frankly, sometimes I WISH the thing would burn to the ground (assuming no injuries or property damage.) Yours doesn't seem like it would be too difficult for a mechanic to fix. Maybe have someone look at it.
Please keep us posted as to what the problem was.

Ok then.,...got that sucker fixed. I followed the instructions Yuri had on replacing the voltage regulator and bought one for 38 bucks...Volvo sells em for 177-240 depending on the type! Call Regitar directly and they will give you their local distributor in your area for Bosch Regulators. So I yanked off the old one (tough process coz of no clearance) and put the new one...Voltage now stays between 13.8 - 14.3. Much better than the prior 19 volts! I had to replace the new battery since the old one had run dry due to the overheating/cold state -It was under warranty anyway. I cranked that guy and felt like woohoo!! Thanks Brick guys...I knew you wouldnt let me down. I know I;ve been quiet lately but I now pledge to give help at least twice a month this year on the board. I btw was the guy who did the Evaporator replacement(850dude) but since its winter I kinda slacked off.
Cheers!

Ok then.,...got that sucker fixed. I followed the instructions Yuri had on replacing the voltage regulator and bought one for 38 bucks...Volvo sells em for 177-240 depending on the type! Call Regitar directly and they will give you their local distributor in your area for Bosch Regulators. So I yanked off the old one (tough process coz of no clearance) and put the new one...Voltage now stays between 13.8 - 14.3. Much better than the prior 19 volts! I had to replace the new battery since the old one had run dry due to the overheating/cold state -It was under warranty anyway. I cranked that guy and felt like woohoo!! Thanks Brick guys...I knew you wouldnt let me down. I know I;ve been quiet lately but I now pledge to give help at least twice a month this year on the board. I btw was the guy who did the Evaporator replacement(850dude) but since its winter I kinda slacked off.
Cheers!