Originally Posted by bbhero
Keep in mind the following...
1) Biggest issue .. how long that battery may have sat on the shelf prior to you buying it. And that a regular flooded battery loses 5-12 percent of it's charge per month just sitting there... That kills battery capacity and longevity. Always check that date of manufacture.
2) Newer vehicles do not fully charge a battery... They in fact tend to keep a battery at or around 80-85 percent of full charge. Saving gas mileage by not charging the battery while driving down the road. Add to that fun stuff.... Newer Vehicles as compared to older vehicles have so much more draw on the battery while just sitting there... Security, ECM functions etc etc... And 50 milliamps per hour do add up over time... Especially when the cars alternator is.not programmed to truly charge that battery.
This ^^^, possibly. Is her car a newer vehicle?
I know this slaps "bitog" all over my polo shirt, but I just installed a 50W PV panel on the shell of my truck, specifically because I've consistently measured the battery as incompletely charged. I've gone outside a few times to watch it - and it reaches 13.7V (the controller's set point) after about 5 hours of full sun, every day. It pushes .9 amps in cool, full sun, and then rolls off with less current after that.
Even with the oversized battery (H8 in an H6 application), it spins faster. Battery is over 3 years old, when the PV was added. It'll be neat to see if it makes a difference, or if heat remains the bigger factor in aging.
We had an AAP gold quit right inside of warranty, and a silver quit right outside of warranty. Switched to JCI AGMs across the street at AZ, but also just warrantied a 2 year old AGM after it tested weak. It was 6mo old when we bought it, being the only one in stock. There's a lot changing and too many variables to just draw a simple conclusion.
-m