Battery Low

[ET16]

I checked the cells on the battery for my Saab 9-5, a recent Interstate (12/14), and was surprised to find the acid level about down to the top of the plates. I refilled with distilled water.

I have never had a battery this low that was so new. I can't explain it, although I know turbos make a lot of heat under the hood. I also don't think I'm overcharging.

 

[andyd]

Easy to verify charging voltage with a volt meter. As long as the plates are covered, no damage has occurred.

 

[69GTX]

When I bought my last car in 2012 it had a 3 year old battery in it. When it failed to start a couple months into winter I found that the fluid levels were below the cells. Lots of crust between the plates too. I added a couple cups of demin water and charged it frequently from then on. Most of that crust redissolved. It went another 3 years after that and I added water once per year.

 

[4wheeldog]

Did you check it when new, to see if the cells were full? I have found a number of new batteries with the plate barely covered, as delivered.

 

[old1]

If the battery never had the proper amount of electrolyte from new, an you add water to it, won't you always have a battery that will not quite be full charge??

 

[ET16]

Originally Posted By: 4wheeldog
Did you check it when new, to see if the cells were full? I have found a number of new batteries with the plate barely covered, as delivered.


I thought of that, but I didn't check it when new. I have another Interstate that is 2 or 3 months old, and it was a little low, too.

 

[cat843]

The charging rate could be too high at driving speeds but not at idle when its normally measured.

I would fill the cells to the proper level and keep your eye on it.

 

[eljefino]

The Saab having GM genetics might put out a few more 1/10s of a volt to charge GM's maintenance-free batteries. The chemistry is slightly different. Since your caps came off the Interstate easily, it's a "maintain me" battery, which, ironically, may need somwhat more frequent top-offs.

 

[SHOZ]

Better off to leave it a bit low but the plates covered. A lot of battery issues are from adding too much water. This leads to acid being 'pushed' out when charging and getting all over the cover. When the acid has left the battery adding more water just makes it weaker.

Usually see this big time with fork truck batteries.

 

[gathermewool]

Originally Posted By: old1
If the battery never had the proper amount of electrolyte from new, an you add water to it, won't you always have a battery that will not quite be full charge??


So long as the plates are covered, that is all that matters. The charge is in the plates, not the electrolyte.

Originally Posted By: SHOZ
Better off to leave it a bit low but the plates covered. A lot of battery issues are from adding too much water. This leads to acid being 'pushed' out when charging and getting all over the cover. When the acid has left the battery adding more water just makes it weaker.

Usually see this big time with fork truck batteries.


+1

Either maintain the level just above the plates and keep an eye on it, or raise the level just to above the plates, complete a charge, and then add some distilled.

 

[jrmason]

Unless your battery is below the plates you should not add water to it until after you've given it a thlrough charge.

Here is how to determine what a thorough charge should be for your size battery.
http://www.batteries-faq.com/activekb/questions.php?questionid=55