The other battery was bought on Ebay and lasted only about 1 year (I bought it as a spare). The failure mode on that battery was that it would go from ~40% charged to almost 0% quickly, never giving me a warning and going into hybernation mode instead. At least I didn't lose any work. I'm sort of sorry I got rid of that battery as I think it was in better shape than the current one.
(Neither battery was on the Dell recall list.)
Now, I think I have another new spare at home with Stratus bought. And I have the one in smozz laptop. Which is good with my upcoming travel schedule.
The first question is, how bad is it to always (or mostly always) run the laptop with the battery installed and on AC power? Is this the equivalent to recharging your cell phone twice a day (which experience shows will kill the cell phone battery)?
And the second question is, given smozz's battery is about a year old and has pretty much always been run on AC, is there any point to replacing her battery while I'm at it and / or running her laptop on AC without a battery in the future?
Sorry if I'm not being very coherent, I only got about 4 hours sleep last night and 6 the night before. This hotel is not a keeper (underlying bed is too hard with a soft pillowtop, which IMHO is the worst of both mattress worlds).