Battery Question

[moparmaniac59]

I don't know a whole lot about car batteries. I just hook them up and hope they work. Years ago many batteries were "maintenance free" and the batteries had no fill caps or any other means for filling them should it be needed. Now there are "maintenance free" batteries that have fill caps and they really aren't maintenance free. I have such a battery. I've noticed it has become weaker (it's about 4 years old). The car sits for long periods without being driven and I do from time to time, put it on a charger.

I looked today at the fluid level and it was quite low. I added distilled water to the cells & then put it on the charger again. My question is since this fluid has evaporated, I'm guessing the acid has evaporated as well as it's mixed with the water. Topping it off would seem to further dilute the acid content. Does any one know if this would weaken the battery further than it is already? Obviously you can't let it go dry or expose the tops of the cells. Just wonderin' 


                                                                            Matt B.

[72cudamaan]

Just the water evaporates, leaving the acid in the battery. As long as the battery wasn't dry
and you're just topping off the cells you should be OK. You could use a hydrometer after charging
the battery to test each cell as well.

[Super Blue 72]

Man, I haven't played with a battery hydrometer in years.... I don't remember seeing a battery with fill caps, maybe I just never noticed.  Yeah, make sure the battery hydrometer is used.

[moparmaniac59]

Thanks for the info. I think I have a hydrometer somewhere. I would have thought the acid would evaporate as well. I was just topping off the cells. It is an older battery and cranking the 543 with 11:1 compression is now getting hard on it. I think I'll put this one in the Barracuda with the 360 and spring for a new one for the Chally!! 

                                                                  Matt B.

[Super Blue 72]

FYI- I replaced a couple of batteries in my cars and although they are normally stocked at the store for most sizes, I ordered online and I used a coupon code for a discount through Advanced Auto.  The battery was like $99 and I had a coupon that had a discount of $30 off $100 so I got the battery and a jug of washer fluid and got $30 off.

I chose the option to pick up in the store and your order is processed in like 30 minutes.  By the time you drive there and eat a candy bar you order is ready and you get the discount.

Search around and see what discounts are offered by different store online. 

[moparmaniac59]

Thanks for that info Phil, that's always good to know. I did top off my battery with distilled water (NEVER use tap water in a battery!!  ) And was able to put a full charge on it with the charger. It should last another year. Our local Pick-N-Pull sells used batteries for $30.00 bucks. That's any/all batteries regardless of age/condition/size and I must say, the last time I was there saw several 2011 (year) batteries that had big CCA's and were probably removed from large SUV's. Not bad for $30 bucks. Considering I keep a fleet of cars running (7 vehicles) for myself and family, it's a good option for low cost upkeep!! 

                                                                         Matt B.

[Super Blue 72]

7 vehicles?    That's like a full time job!!!

[CudamanTom]

I just wanted to add,
The acid also evaporates in active batteries. It's a water/acid mix inside the battery.
Just using a hyrometer will only show if you have voltage. Typically, a dying battery will lose it's cranking amperage power.
Just because your showing 12v doesn't mean it will turn of the engine.
If in doubt, take it to a parts store and have a full test done for free.