Battery Voltage.

An interesting data point.

As a backup battery (garage stored), I bought an Odyssey AGM 24F in Dec 23. Fully charged it with a Pulsetech XC400 and then float charged it using a Batteryminder 12117 at 13.60v for the last 25 days. Before making today’s measurement, I allowed the battery to sit unplugged for 24hrs.

Odyssey customer service considers a 100% fully battery is >12.84v. Today’s measurement was 12.89v at 50F.

Based on the date code Dec 22 and my purchase in Dec 23, the battery sat in the Advanced Auto warehouse storage for 12 months. Definitely terrible for flooded cells and not ideal for AGM but the initial out of shipping box measurement was 12.73v. According to customer service the battery was manufactured in July 22 and recharged in Dec 22 before leaving for Advanced Auto.
AGMs do better in storage than flooded cells and require less frequent charging. Optimally it should have been charged in July 23 - every 6 months or if life was perfect it would be Cinderella fairy tale.
Lol

IMG_7172.jpeg




IMG_7440.jpeg
 
Last edited:
Hi Guys.
Thank you all for taking time to help.

My Jeep is having some issues, so i had it connected to a scan tool. I noticed the tool was only registering the Battery at 11.9v at the top of the screen. Now the engine seemed to be cranking ok that morning. With engine running the display says 14.6v. I was unsure what a healthy 12v battery should be reading. Google suggested 12.6v, which thanks to you guys seems correct.

Anyway, as the Battery is at least six years old i have changed it. I got an Excide Platinum, 100ah and 900cca.
Didi the new battery fix your Jeep issues?
 
Didi the new battery fix your Jeep issues?
Hi bernie.
Yes, the new battery is great. Fires the Jeep up in the cold winter mornings just fine. It cranks much quicker than the old battery. I do occasionally put the battery on a ctek smart charger to top it up.
 
An interesting data point.

As a backup battery (garage stored), I bought an Odyssey AGM 24F in Dec 23. Fully charged it with a Pulsetech XC400 and then float charged it using a Batteryminder 12117 at 13.60v for the last 25 days. Before making today’s measurement, I allowed the battery to sit unplugged for 24hrs.

Odyssey customer service considers a 100% fully battery is >12.84v. Today’s measurement was 12.89v at 50F.
...............
Your Batteryminder must be an older version if it is floating at 13.6V (at 77F). Around 3 years ago they decreased float voltage to 13.2V (at 77F) even for their chargers that had a dedicated Odyssey charging profile.

If you "exercise" or "format" your Odyssey with a series of 250A discharges, you can bring the resting voltage up to 13.00V or higher. When my Northstar TPPL battery was new its resting voltage (OCV) was 13.08V at 60F, 24 hours after charging.

https://batteryuniversity.com/article/bu-701-how-to-prime-batteries
 
Last edited:
Your Batteryminder must be an older version if it is floating at 13.6V (at 77F). Around 3 years ago they decreased float voltage to 13.2V (at 77F) even for their chargers that had a dedicated Odyssey charging profile.
I bought a couple Battery Minders a couple years ago and noticed the same issue with the lower float voltage when on AGM setting, or with my dedicated AGM Battery Minder. I called them and they said they did this due to customers experiencing overcharging and damaged batteries.

What is interesting is they have not changed any of the user manuals or documentation. I wonder if Odssey is aware, as they still list Battery Minders with an AGM setting, or dedicated AGM chargers as "approved".
 
Back
Top Bottom