The other day I hopped in my car and when I started it the battery was completely dead. Dead to the point that even the lights on the dash were barely visible. And it was just after one day of not driving it. I jumped it and after that it ran fine without issues so far.

Until yesterday when I was driving and I noticed when slowing to a stop the RPMs would suddenly jump a bit. For example the RPMS would be going to 1k while slowing down to a stop, and then suddenly it will jump to 1.5k - 1.8k rpms. This happened several times.

I did some research and found this:

https://www.clublexus.com/forums/gs-...ery-drain.html

and also this TSB:

http://www.revbase.com/BBBMotor/TSb/...dPdf?id=195332

This potentially answers my first issue with the battery drain but not my car's strange behavior.

Any ideas?