Low Battery in slow traffic

Hey Lou. Welcome to Priuschat.
Check out my thread entitled "Milage or Time" in which I tried to decide whether it's best to take a sideroad where I can maintain some speed and trim some time or take the main highway but sit in traffic more. My original thought was that sitting in traffic would give my milage a huge boost. After all, that's what the battery's for, right?

Turns out that my battery did exactly what yours did. And you didn't have to turn the A/C off. Unless there's a huge problem with your car (which I doubt) you would not have killed the Hybrid battery. My mileage went to crap because in the first ten minutes I creeped on battery power (called "stealth" mode") which drained my battery to 2 bars as well like yours. For the remaining ten minutes, the Internal Combustion Engine (ICE) ran like mad to recharge it.

You were lucky. You could get back up to speed to recharge. It took a long time for me to recharge the batteries.

Oh, and here's 50 points! Don't ask what they're for or I'll take them back.

 

Your engine did no charge the battery b/c it determined that you were in slow moving traffic and slowly draining the battery and that it did not yet need to recharge the battery. Had it gotten low enough the ICE would start, charge your battery a little bit, and shut down again. It will repeat that cycle as necessary.

Know also that, even if, somehow, you'd have succeeded in draining the battery to where it showed only one or even no bars on the MFD that you would still have had at least 40% state of charge (SOC) in the battery itself. It did exactly what it's supposed to do in slow moving traffic, it operated perfectly and there is no problem.