Earlier this year, I replaced my two Optima yellow tops with three Optima red tops. One of the reasons I did this was to replace the original 3/0 cables with 4/0 cables and change to a bus bar configuration for optimal current flow from the three new batteries. That discussion is at: Battery Cable Upgrade and Pricing (http://www.foreforums.com/index.php?topic=26886.msg218150#msg218150) The other reason I did this is that the engine battery voltage (using cheap plug-in meter) dropped significantly during starting, although it bounced back once the alternator was running.
I took the fully charged yellow tops out of my coach about 6-7 weeks ago. Just for the heck of it, I measured the voltage tonight. The one that has been setting in my livingroom (don't ask) measured 13.01 volts (date code 11/11). The one that has been on the patio measured 13.04 volts (date code 4/12).
I did not load test them, but they have not been in any kind of circuit in over 1 1/2 months. To still have that much voltage stored seems *to me* to imply that they still have significant service life left.
I guess my first question is how do they still have so much of a charge after that period of time? (They were charged by my coach charger - set to AGM mode - using the boost switch -- really long, long story.)
Am I interpreting their "goodness" correctly, based only on that current voltage reading?
Thanks for any and all input,
Trent
It would appear that they are good, however the only way to check a battery is a load test.
Trent,
If they haven't dropped anymore than that they don't have an internal short, some natural loss is expected as with any automotive style battery. If they load test good I wouldn't be afraid to use them.
Pamela & Mike
No. What bruce said (above). Link below - Page 3, Testing:
http://www.eastpennmanufacturing.com/wp-content/uploads/EPM-Heavy-Duty-AGM-Guide-Technical-Update-1401.pdf