turbo_pwr

Ok was at the track half the day then did a 7 to 8 hr drive home. Stopping for about 15 mins 3 times. The car kept smelling like rotten eggs, but I never saw anything wrong with the oil during the stops so I kept going. I get home pop the hood to get a better look and hear something coming from the battery. I pull the cables take out the Optima Yellow top battery and can actually see the liquid inside boiling. In case you are wondering there is a little clear window line down the side. Never had this problem before and the engine never saw more then 70 Celcius the entire ride home. I have the Mugen Header with heatshield and the stock black heatshield is still there. Is this just a defective battery? Couldn't find any leaks or crack in the battery shell casing.

Elistan

turbo_pwr, I was almost sure I knew what was going on, until you said you saw the "boiling" after disconnecting the battery...

My guess was - your battery is shot, yes, but it has nothing to do with boiling. I suspect what you're seeing is electrolysis, the decomposition of water into hydrogen and oxygen through the application of electricity. It happens when a battery's chemical composition cannot store electricity any longer - it's basically being overcharged, so the electricity has to go somewhere. It's a rather dangersous situation, since it's releasing hydrogen and oxygen. (BOOM!) Some of the sulfer from the acid in the batter can escape this way, hence the rotten eggs smell.

Of course, it requires a current to happen, so I'm not so sure...

turbo_pwr

Definitely saw it after disconnecting the battery. I yanked it out of the car and put it on the floor and the liquid was still moving inside. Optima batteries suck then, the first one I got wouldn't hold a charge and this one has only lasted about 2 months.

honda9krpm

that doesn't sounds too good
I thought Optima use gelcell and not liquid per se

N8R

turbo_pwr,

Have you had your alternator tested lately? In most casts, a boiling battery means that it's receiving too damn much current!

I've seen this before - most notably in a friend's boat... The battery was boiling, and literally bulging at the seams because his voltage regulator was improperly installed from the manufacturer. The whole boat (brand new 32ft. Cruisers) smelled strongly of eggs.

I'd run some tests before spending your time and money on a new battery.

Best Regards,

-nem

lukep6470

Get a mulitmeter and measure the voltage between the battery terminals with the engine running. Get someone to rev the motor a couple of times.

If the voltage accross the battery gets over 14.5-15Volts then the regulator in the alternator is shot. If this is the case it has probably already stuffed your battery anyway.

Intrepid175

This is a definite possibility. It's normal for a battery to "off gas" or boil a "little" when being charged but but it shouldn't be vigorous enough to smell rotten eggs in the car from it.

I'd get the charging system checked!

Good luck & Drive Safe,
Steve R.

Scablander

I was driving my Mazda and noticed the rotten egg smell. Got to work and had only one headlight working. Went to auto parts store and bought a new headlight bulb. Installed it and turned on the headlights to check the repair. Other headlight burned out...I saw it do so in my car's reflection in the store window. Bought another headlight bulb. Installed it and the other headlight burned out again. Digital clock in auto went dead. Clue light came on in my head. Used multimeter to determine that charge voltage was way high. Replaced alternator as internal voltage regulator had failed. Was one lucky sucker...main computer or other very expensive auto part could have gone south. Luckily, the only damage was three headlight bulbs and digital car clock which will never work again. I recommend that you track this problem down now before serious damage results.