# Acid overflowing from battery

**URL:** <https://community.cartalk.com/t/acid-overflowing-from-battery/46061>\
**Category:** Maintenance/Repairs\
**Tags:** batteries, sl, saturn, electrical-wiring\
**Created:** [March 14, 2010, 4:42am UTC](https://community.cartalk.com/t/acid-overflowing-from-battery/46061 "2010-03-14T04:42:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wrboykin](https://avatars.discourse-cdn.com/v4/letter/w/8e7dd6/32.png) [@wrboykin](https://community.cartalk.com/u/wrboykin)\
**Post date:** [March 14, 2010, 4:42am UTC](https://community.cartalk.com/t/acid-overflowing-from-battery/46061/1 "2010-03-14T04:42:45Z")

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Acid is flowing out of the battery onto the car frame. The alternator was replaced 18 months ago by the Saturn dealer and the name brand battery is about 2 years old. Battery vendor checked system & said both alternator and battery met specs, found no problems. Does anyone have any suggestions as to the cause of the problem?

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**Author:** ![meaneyedcatz](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/meaneyedcatz/32/692_2.png) [@meaneyedcatz](https://community.cartalk.com/u/meaneyedcatz)\
**Post date:** [March 14, 2010, 5:41am UTC](https://community.cartalk.com/t/acid-overflowing-from-battery/46061/2 "2010-03-14T05:41:05Z")

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The electrolite (spelling) /acid is boiling out from getting to hot. Something is wrong, go to a different shop.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [March 14, 2010, 7:23am UTC](https://community.cartalk.com/t/acid-overflowing-from-battery/46061/3 "2010-03-14T07:23:20Z")

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Other than an overcharging situation about the only thing it could be other than that is a cracked battery case. (cracked around a terminal post during installation or whatever)

Drop by an AutoZone, Checkers, O’Reillys Auto, etc. and have them test the alternator output just to get another opinion. You state the “battery vendor” has checked this but keep in mind that this vendor may not be a mechanic and could possibly be under the impression that a certain voltage may be acceptable when in reality it’s not.  
It’s a bit baffling that this vendor can’t explain a battery leak.

For an FYI, the voltage reading you’re looking for will vary based on the state of the battery charge, the load applied to the elec. system, etc. but should be around 14 volts give or take a tiny bit with lighting off, A/C off, cooling fans not running, etc.  
If the voltage readings are in the 15 volts or so category then that’s too high and the battery is being overcharged.

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**Author:** ![oblivion](https://avatars.discourse-cdn.com/v4/letter/o/3ab097/32.png) [@oblivion](https://community.cartalk.com/u/oblivion)\
**Post date:** [March 14, 2010, 9:20pm UTC](https://community.cartalk.com/t/acid-overflowing-from-battery/46061/4 "2010-03-14T21:20:09Z")

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They may have checked the voltage, saw that the alternator was putting out 14 volts or so like it should, and decided it was working fine. However, the alternator needs to STOP putting out a full charge when the battery is full, and I doubt they checked for this. A bad voltage regulator or wiring problem so that the regulator isn’t getting a proper signal will do exactly as you describe–cause the battery to boil. This will quickly kill your battery too.