SailNet Community - View Single Post - Winter is coming -Battery Question?
View Single Post
post #14 of Old 11-11-2012
Maine Sail
Senior Member
Maine Sail's Avatar
Join Date: Jan 2003
Location: Maine Coast
Posts: 6,412
Thanks: 22
Thanked 305 Times in 236 Posts
Rep Power: 18
Re: Winter is coming -Battery Question?

Originally Posted by sapo View Post
hopefully this is related enough not to be off topic. I'm buying new batteries for my solar-charged house bank. I'm told that one should test the batteries at the store to make sure you're not being sold old stock or otherwise batteries that are otherwise less than optimum. but how do you test 'em? just with a hydrometer?

You can just measure the open circuit voltage with a volt meter. There is no real benefit to measuring the SG on new batteries because the cells are still new and un-cycled...

They should be above 12.6V or darn close to it. Try to buy batteries with matching date codes and the freshest date codes on the shelf. For example if there are four group 31 batteries and you need two, and the date codes look like this:


You want the two J12 date coded batteries. they theoretically should match better and have been produced at or about the same time. Often times the letter is the month with Jan being "A" and the year being "12"... This may not be the same for all batteries so ask your supplier how to interpret the date codes and choose the freshest batteries..

-Maine Sail / CS-36T

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Images In Posts Property of Compass Marine Inc.

Last edited by Maine Sail; 11-11-2012 at 11:25 AM.
Maine Sail is offline  
Quote Share with Facebook
For the best viewing experience please update your browser to Google Chrome