E1505 - Battery Not Detected SOMETIMES

I've got an E1505 here. The battery lasted less than a year, and then I replaced it with a brand new battery. This has been in there for at most a month now. The past two days I have had an interesting situation going on. The computer is running Vista Home Premium, and it's running on AC. The battery seems to be working fine. It's detected fine, the PC runs off of the battery, and it charges as well. It's not set to suspend, hibernate, or anything like that at any time; these features are all deactivated because I am never in a situation to use them.

However, for the past few days, I have closed the lid and then gone to sleep at night, but when I have opened it up the next morning, I have the red X icon that says the battery is not deteced. I've unseated the battery and clicked it back in each time, and it is immediately recognized and operates completely normally as described above after that. The first time that this happened, I thought it may just have been some odd thing as can happen now and then with computers, and I ignored it. I went through my day using the E1505 as usual: leaving it unattended for minutes or hours while doing other things, closing the lid before going to the store, opening the lid again, etc., and it worked fine. However, when I awoke this morning the X was there with the no battery message. I again unseated and reseated the battery, and all seems normal.

I'm a bit confused, as well as concerned about the situation. Any thoughts? Thank you!

 

Is your replacement a genuine Dell battery, or a third-party part?

 

It's not a Dell battery, but as I said it's been working for about a month now and so the thought that it's incompatible in some way that is causing this doesn't make sense to me. Were that the case, why would it have worked properly and then suddenly changed?

 

Update - it had done it again when I came home tonight.

If I unplug the AC, the computer immediately switches to battery power, recognizing the battery and switching the meter to battery. If I plug the AC back in, the computer immediately switches back to AC with the battery/plug icon and charges normally. This is different from every other account of "battery not detected" trouble I've read in researching this (quite a few) in that in all of those cases, unplugging the AC caused the computer to run off of battery but without "realizing" that it was. In other words, the icon would remain the Plug with the X over the battery and the PC would think it was on AC power even while operating off of the battery.

 

I have a question for anybody with an E1505 running Vista. When the battery charge reaches 100% and you hover over the icon, does it tell you it's operating on AC power, or that the battery is fully charged, or does it say "100% available (plugged in, charging)"