High Voltage Battery Charging Question

[alcor]

Recently while driving on Interstate 5, traffic was nearly stopped for more than an hour because of roadwork. I say nearly stopped because from time to time one was able to creep forward a few feet. I noticed that the battery indicator really began to drain, as I expected it would. I also anticipated that the ICE would come on as often as necessary to make certain that the battery would not completely discharge. The battery actually got as low as one brown bar before the ICE came on. During this period, the battery indicator never got above two brown bars. At one point I was beginning to worry that the battery might lose it’s charge completely. In actuality, the ICE rarely came on. Now this was great from a fuel usage perspective, but it did have me a little concerned. When traffic was finally allowed to proceed, the battery quickly charged back up to normal levels, and I achieved approximately 50 mpg during the 300-mile trip.

In a situation like this, would I have been better off to have actually switched the car off and then put the ignition in the accessory mode, or was it OK to simply let the computer manage the power system?

Thanks,

Alan

[deh2k]

"Trust the Force, Luke!"

Your Prius knows what it's doing--so just let it do its thing. 50 MPG in stop-and-go traffic is awesome. Imagine what would have happened in an old fashioned car.

[DanMan32]

At 'idle', the system will let the battery go to pink, and will remain there, starting ICE just long enough to maintain 1-2 bars, as long as you are not in Neutral. This is normal. It is waiting for a time when it can use the ICE for propelling the vehicle, rather than only providing electricity.

[efusco]

It is normal normal normal. There is no need for the ice to charge above 1-2 bars, it "knows" it will be able to recharge once you resume 'normal' driving. If the bars make you nervous switch off the Energy screen.

FWIW, in truely 'stopped' traffic I shut off the car or put it in Park if I think I might need to move every so often. This is one place where the EV button is sweet b/c I can shut off the car, then start back up if necessary, hit the EVb, then creep forward as necessary and shut back down minimizing battery drain and never seeing the warm-up cycle until traffic gets moving or the battery level gets low enough to force that (which takes longer this way than by leaving it in Drive.

[Tideland Prius]

Good idea doc! I could've used it during the border wait on Friday. I got drained from 5 to 2 bars was still 4 cars behind customs.

[Sufferin' Prius Envy]

After creeping along for a couple of miles in a happy traffic jam of people looking at Christmas decorations, we came to a stop sign at an intersection with a busy arterial road. With five adults in the Prius and one bar showing on the MDF, I was quickly indoctrinated to just how much the Prii’s Atkinson cycle ICE relies on the battery and electric motor.

Lets just leave it at: It is NOT as good idea to try to jump out into fast moving traffic in that situation!!! :cussing: ops:

[NuShrike]

... I was quickly indoctrinated to just how much the Prii’s Atkinson cycle ICE relies on the battery and electric motor.

Lets just leave it at: It is NOT as good idea to try to jump out into fast moving traffic in that situation!!! :cussing: ops:

Well.. and the heavy clamping action from the traction control esp if you're turning the wheel and then flooring it.

[alcor]

Thanks everyone for all the good information. This forum is a great place and we're lucky to have it. Patrick, excellent point about acceleration without help from the electric motor. That is indeed something to remember.

Alan