If you use a batter tender come inside...or if you really know electrics

[USAFPILOT]

I have recently had some trouble maintaining the charge in my battery, so I got a battery tender and left it on it all night etc. When I came out in the morning the battery charger said the battery was charged and it did crank right up with no problems. But I noticed that all the electrics in my car were flickering and the voltmeter in the DIC was cyling between 15.0 and 14.5. After driving it around for a while it settled down to about 14.2 which had been about normal, and at idle with the AC running it was 13.8 or so. After the drive the flickering had ceased.

To me the flickering is weird...anyone else? Any ideas? I am concerned about hooking the tender back up to the car.

I could get another battery I guess...but I dont think it is ruined...or is it? I guess I'll at least take it to autozone for a check.

Ohh...and I never had any flickering before the battery tender. Except for the time I tried to jump start it and in the process fried my BCM. But it only flickered once and then it was all dead.