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Topic: When Does a Battery Need to be Replaced? (Read 400 times) previous topic - next topic

When Does a Battery Need to be Replaced?

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  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

Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385

Re: When Does a Battery Need to be Replaced?

Reply #1 –
It would appear that they are good, however the only way to check a battery is a load test.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: When Does a Battery Need to be Replaced?

Reply #2 –
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
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."
 

Re: When Does a Battery Need to be Replaced?

Reply #3 –
Quote from: TulsaTrent –
Am I interpreting their "goodness" correctly, based only on that current voltage reading?
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
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"