Water coming out of battery


sonhow, water is coming out of my batter. the bottom pan gets water in it after a short drive. any thoughts?




Check the output of the alternator to the battery. If the voltage out of the alternator is over 15 VDC, it will boil the electrolite out of the battery. And what appears to be water is actually sulfuric acid.



If this liquid is really coming out of the battery, it should be quite acidic. If you don’t have some litmus paper to test it, try sprinkling some baking soda (or better, lime) on it and see if it fizzes. You should also open up the battery caps and see if it’s very low on water/electrolyte. If it is, is there any trace of water around the filler caps/breather cap? An overcharging electrical system could be causing problems (forcing water out of the battery).

If it’s just plain water (no acid), and isn’t coming out of the caps, look around for some other place where water might be pouring into the battery pan. I take it your short drive is on dry roads and no puddles? Is your battery close to the A/C evaporator, and the evaporator drain is clogged and water is slopping over into the battery pan? (More likely it would be spilling inside the car.) What make, model, year, and mileage?


its a94 nissan pickup v6 with 165k. the alternator voltage is 13 vdc. just had the starter replaced… the roads are dry and the ac evaporator is not near. thanks for the input


The next thing to check for is a cracked battery case.



Act quickly to neutralize the liquid with a solution of baking powder or baking soda. That’s sulfuric acid and it will eat away your battery tray if you allow it to linger.


The 13 volts dc is NOT adequate to recharge the battery. Why don’t you TEST the liquid. As noted by MrPhil? Baking soda and battery acid will fizz like an Alka-Seltzer. A white cloth will show green if the liquid is antifreeze If it’s another oily substance, you’d be able to tell that, too. You didn’t say whether the electrolyte in the battery is low, or not. Is it? Is the antifreeze, and other fluid levels (oils, etc.) where they should be? //// [One’s got to love this new feature of being able to edit after submitting a response. I came back after leaving out a word.]


the battery is not low on water yet. i’ll double check battery case for a crack. thanks


hellokits suggestion of checking ALL the fluid levels is really important.

your battery doesnt just “make” water. it has to come from somewhere.

either the battery (the mentioned acid) is getting boiled, or a spraying (loose) radiator hose, radiator cap, or even radiator.

but wherever it is coming from will eventualy get low. that would really point to where the problem is. but you have to check all over, in all locations.