nanoman9

Thanks Dave, good to know. I'm guessing I never realized that in the past when batteries have died on me on other cars, because I've had instances where a short run like that will charge it enough to start again a few hours later. And generally I drive most days. So I'd always thought only 20 minutes was enough, when in reality it must have really finished charging the next few time I took it out and I was just lucky it was able to start again after the short drive. This Impreza doesn't get driven every day so that makes sense. By your response, I'm guessing at least a couple hours is needed...

Ah, many thanks! Sorry, I totally forgot to mention it was from a 2012 Impreza. So, I wasn't sure if it was a battery from 2011 (the '11D') or whether the battery was from 2013, (since there's a '13') which would make sense since it was purchased certified pre owned from a dealer in 2013. I thought maybe they had replaced it (and that maybe the dealers used the same batteries as factory, since it seemed these Panasonics were common for new Subarus). It got a death knell from a dome light left on. It's not quite as cold here in Chicago as it is for you guys up north but not something I want to be messing around with on a cold winter night. I had tried to charge it with a 20 minute drive, and it was able to start up again, but then after sitting for ~3 days, it wouldn't start. I was thinking if it was from 2013, I'd give it a slow charge to try to restore it, but if it's from 2011 it looks like it's time for a new one.

Thanks Rooster, I already saw that one and a couple dozen similar sites. :-/ Indeed it suggests April 2011, but nothing specific for Panasonic.

Hi Everyone, Could anyone confirm the manufacture date of this battery? I'm guessing it's April 2011 from the '11D', but the other digits here could make sense based on the year of the car and when I purchased it used. It's a panasonic 55d23l battery. Many thanks!