Same batteries, different weights?

[kaotic]

I have 2 - 27 class deep cell interstate batteries that are basically brand new. I was really bored yesterday and weighed them and one weighs 51lbs and the other weighs 53lbs. Is there something wrong with one of them or is this normal?

[kchace]

Water level?

[kaotic]

That is kind of what I was thinking. What steps do I need to take to I guess top off the water level in the battery?

[rwidman]

I don't think you'll find two pounds of difference in the electrolyte level.

Go back to where you bought the batteries and ask about the weight. While you're there, ask them to show you how to check the electrolyte level and how to add water to the appropriate level.

[VanW]

Bored much?

[carlb1120]

A battery manufacturer often increases CCA by installing additional plates within the same case dimensions. I would have the battery supplier check the CCA with a meter to insure that do indeed have identical batteries. Look at the different weights and CCA for Deka batteries of the same external size. http://www.eastpenn-deka.com/assets/base/0194.pdf

I am assuming that these are maintenance free batteries. If that's the case, it's unlikely that the difference is electrolyte.

[Butch Davis]

Two pounds would be approximately one quart of electrolyte, no?

[sandyda]

Store-brand batteries are built to the store buyer's spec, and may vary from time to time, more from concerns about profitability than anything else. Battery factories can put different thicknesses of plates in the same size case, and the weights will vary. Heavier batteries have thicker plates and more amphours, (think deep cycle) while thinner plates (starting batteries) can give a bigger kick, as in higher CCA. A two pound difference due to fluid level would mean one of them is nearly dry!