I got the volt meter installed and so took the ride for a drive. As I am driving the Volt meter reads 17 and I think to myself "I have a good alternator". When I parked the car and opened the hood to check it out I hear a hissing sound coming from the battery like if it's got a crack or leak of some sort. My question is: Can the alternator be over charging the battery causing it to boil or something? Not sure how old this battery is but my lights sure are bright. Thanks
run!!!!! better check out your alternator .... it can over charge a battery and cause serious damage to your car.... not to mention you....
If it's really charging at 17 volts, then you may have a BAD alternator or regulator, depending on what type of charging arrangement you have. That hissing you hear is hydrogen and oxygen from boiled acid escaping from your battery. It's a snake ready to bite you in the ass. Be damned careful, the mix is explosive. Fix it immediately, before you start it again.
Your alternator is overcharging. The hiss you hear is a hydrogen bomb waiting to happen. Charging voltage should be about 13.5 to 14.8 volts. You will ruin the battery, and worse cause an explosion with it overcharging.
Yeah, you are WAY over charging and causing the battery to offgas, might want to sprinkle some baking soda on anything in front of the battery vent and wash it off or you will see where it all sprayed. And then check your regulator or alternator, which ever you are running...
I'd leave the lights on for awhile to discharge the battery some and then have the regulator checked in the alternator. I'm thinking that it's stuck in position.
Most likley a bad voltage regulator, rather than an alternator unless you have a newer internal regulator alternator.
Damn! Makes me jumpy just reading this thread. Keep away from that battery with sparks or open flame and go get another alternator if it's internally regulated or a new regulator if it's not.
You could also have a bad ground between the alt case and the battery ground which will confuse the regulator and make it run at a higher than normal voltage. So check the grounds first by adding a jumper from the alt case to the battery neg. If it's still overcharging than it;s your regulator or even miswired alternator. What kind of alternator?
I am not sure what kind of alternator it is, but it is a one wire for sure. I will pull the alternator out and take it to the auto parts store and have them test it and see if it's over charging. If so I'll get a new one and a new battery at that. The guy who owned the car before me used thick speaker wire to run from the alternator to the battery to charge it. I think a better wire will be better as well. (now what gauge wire, 18?)
More than likely voltage regulator related... or something to do with that funky speaker wire job. I'd have to see what you have there, but 18 awg is probably very inadequate. Also look at the grounds as mentioned above. Bob
I heard the same hiss from a battery a few years ago, but before I could turn to get away, it exploded! Covered me, my old tractor, and the side of my shop with acid. NOT GOOD! And you can't believe how loud it was when it off! I was lucky not to get acid in my eyes, (safety glasses) but it was all over my face and clothes.
Yeah reading this makes my skin crawl. A few years back a buddy stop by open his hood just as I walked up to look under the hood the battery top blew open and empty onto me. Even flushing with water it burned like HELL! Fix it! Slim
Riiiight...............about the mess that acid makes. I had my engine and compartment mostly cleaned up and painted in the 49 Plymouth coupe. Then, one day, when it was darn cold weather I decided to try and start it. I've jumped many a six volt car from a 12 volt car without incident. But, I guess I cranked this one just a liiittle too long.....and.....BAM. Fortunately I was sitting in the car pushing the starter button when it went.....not standing by it. I put baking soda, Coca Cola, and other stuff on the mess it made.....nothing really helped much. So.....yeah.....I would definitely be cautious with that leaking battery.
IMO 18 ga is way too small. I use 10-12 ga. The wire size itself will not cause overcharging but as stated above a poor ground will. peace
I was on an all-day Interstate trip a few years back when we started smelling a weird odor. I had just put in a rebuilt OD transmission and suspected it as the source. Pulled off at the next exit and shut everything down and heard the dreaded hiss from under the hood and raised it. The battery was actually throbbing! and at each 'throb' a small puff of, I guess it's hydrochloric acid steam, would puff out of it. We backed way off and while it continued throbbing we found a some shade. After the battery had cooled down completely, I restarted, nothing happened so I drove to the nearest Walmart and got a new battery. Replaced it in the parking lot and never had any more problems. I think the battery was old, outside temps were over 100 that day, and driving high speeds just cooked it and it failed. Luckily it never blew, just cracked. Also, every time I've jumped a 6V with a 12V its blown one of the cells in the 6V. Not the whole battery, just one of the cells. Weakens it just enough so you don't notice until some time later, when you really need it.
When I worked at a marina one of our techs put a battery on the charger and had the charger on the "start" setting. He walked away and the top blew off of the battery and sprayed acid all over the place. He is damned lucky he wasn't standing near it when it blew. Find your problem quick ! That hissing is telling you something. Don
Had a huge AGM battery (8D) on the end of a bank of an EV that I was working on let go. Luckily, I was out of the line-of-fire for the acid spray, but I was left without hearing for a few hours.
A one wire alternator needs a heavier wire to the battery,many of the most common one wires are 100 AMP with that you should have a 6 or 8 gauge wire.I use the Ford style solenoid cables which are flat lugs on both ends and are usually 6 guage for around $5 at most parts places.You should also make sure you have grounding straps,I would run one from a rear intake bolt to the firewall and one from the alternator bracket to the frame.
I worked in a place where I saw 2 go up like that. One was from the spark the hood latch must have made, with luck the hood blocked most of it and the guy just got an acid bath. The other one guy it full-face, with cuts from the battery case. We almost drowned the poor guy rinsing him off. In both cases, a trip to the ER was next. If you do have to work on something like that, open the hood carefully (sometimes you can smell the battery percolating) and throw a damp towel over the battery and carefully undo the connections, if the battery is HOT to the touch and or bulging, let it cool off first. Bob
As mentioned 17volts is extremely high. If the alternator and its regulator check out fine. Verify that the engine has a proper ground. If not the alternator may not be able to properly read the batteries voltage if the ground has high resistance. It may have been reading a minimal amount of voltage and was attempting to charge the battery at it's max voltage. Check that the alternator does not have an adjustable regulator on it. There are 'race' units offered by PowerMaster than can have their voltage output increased to 18V. Sometimes folks think they know best and crank up the voltage output. Not good. Alternators should never be run at more than 70% capacity. Just because it's 100A alternator, does not mean it is designed to put out 100A 100% of the time. They will burn up. But if you are constantly running the alternator at 70% of capacity, it would be best to upgrade to the next size for longevity. Typical 12V ~65A alternators are more than adequate to power the average 12V system. If music or gizmos are your thing you can look into improving the charge wire size and alternator output to supply those accessories. Make sure all ground bonds between the engine, body and battery are adequate. Be careful of grounding to the frame. Often the frame is isolated from the electrical system. Everything attached to it tends to have a rubber bushing in between.
anything higher then like 14.8 volts becomes dangerous, once had a call out to a car that had the battery exploded all over the engine bay, acid every where
Had a bad alternator blow up a battery in a Ford Focus one time, parts of that battery may yet be orbiting the earth.
First get the alternator tested,Second where is the volt meter connected. It needs to be connected as close to the battery as possible. at the main battery connection on the starter is a good place. From the output terminal on the alternator use a 10 ga. wire. Most of all do these things with safety in mind.
I was working with a 36v 3 battery system once. I was disconnecting the batteries and accidents grounded out one is the cables and had all 3 batteries explode! I was very lucky, happened to be wearing a long sleeveshirt that day (usually dont) and pretty much all the acid stayed on my shirt sleeves except one sloth ended up on my glasses lens. VERY LOUD!! Had about 20 people show up in my area wondering what the loud bang was.
Very scary situation there. Had to replace the alternator yrs. ago in my Corvette. Fired it up after I installed the new one (internally regulated) and the dash lights lit up so bright it almost blinded me. Turned it off immediately, took the alternator back to the parts house for replacement. Internal regulator was bad (this was a brand new piece). Could have been a disaster on many levels aside from the safety issues. All I could think of at the time was having to pull the dash and console apart to replace about a dozen or more bulbs that could have been potentially blown. Be careful!!
Sure dont sound like fun to me Had a side post GM style battery blow one of the posts out of the battery case..enough force to dent the core support on a O/T Tahoe. It also spewed most of the acid all over the engine bay not something i would want to be standing anywhere near
Definately a charging issue. I have seen several batteries blow not a nice site. Make sure when you are working with it wear at least some kind of protection, glasses at a minimum. I know it seems over kill but I had a kid working on my ship who screwed up while messing with batteries and got the acid in his eye. He still does not have full vision in it.
I was a tank mechanic in the army , A tank has 6 batterys in the floor ,,, All 6 blew up in my face at once ... still have problems with my eyes and that was in 1969 ...
The battery is more than likely to be shorted internally which will make the alt over charge and the battery hiss.I would replace battery first than rechack voltage on charging system.Batteries are the main cause of alt failure.I see it everyday.
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