Toyota Prius Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
Happy Easter all,
I sat in traffic last night in Manhattan. I couldn't get through one traffic light for 15 minutes....As I sat there, I watched the battery icon show drainage until there was only 2 bars left. Finally I moved and the battery quickly charged.

Would the battery eventually have drained if I couldn't move? What do I do then? How could I have avoided this. (PS- there were no headlights/heat or radio on).

Thanks.
David
 

·
Registered
Joined
·
1,661 Posts
drtravel47 said:
Would the battery eventually have drained if I couldn't move? What do I do then? How could I have avoided this. (PS- there were no headlights/heat or radio on).

I assume the gas engine wasn't running during the time you were sitting. If needed, the ICE (internal combustion engine) would have kicked on to charge the battery. Not to worry - Little Prius knows what it's doing. :)
 

·
Premium Member
Joined
·
2,815 Posts
Nothing to worry about - if the hybrid battery needs charging, the Prius will (as long as it is in READY mode) will just turn on the gasoline engine to recharge it.

Note that the hybrid traction battery not only powers the electric motor for propulsion, but also the electric motor for turning on the gasoline engine. On the 2004+ Prius, the hybrid traction battery will also power the AC compressor (if you have the front windshield defroster on or the AC on). The hybrid battery will also recharge the Prius' 12v battery while in READY, so that is probably where much of your drain is if just sitting idle in traffic. Otherwise, make sure that your brake is firmly applied to cancel the electric motor's simulated transmission creep...

(Worst case of traffic I've personally seen with a Prius has been over 1.5 hours stationary in the same spot, thanks to the highway being completely closed about a 1/4 mile ahead of us due to an accident... Not fun watching all those other vehicles around us (very few cars, mostly trucks (pickups, SUVs, minivans)) sitting idling that whole time... Never had a problem with heat - engine only came on every so often to warm us back up. Spent much of the time using a Bluetooth phone to do a car conference with a family member, trying to find out what was going on with the accident ahead of us (ask to check local TV stations, and fire up the police scanner...))
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #5 ·
Battery drain clarification

Thanks for the quick answers.
Let me clarify what you all said: The battery would NOT drain if I sat there. How low would the battery monitor go? One bar? No bars? Then what happens?

Also, did you also say that running the air conditioning does NOT drain the battery?

Thanks
David
 

·
Registered
Joined
·
38 Posts
Re: Battery drain clarification

drtravel47 said:
Thanks for the quick answers.
Let me clarify what you all said: The battery would NOT drain if I sat there. How low would the battery monitor go? One bar? No bars? Then what happens?

Also, did you also say that running the air conditioning does NOT drain the battery?

Thanks
David
Another thought - did you have the car in neutral when you were at the stoplight for 15 minutes? The Prius doesn't charge itself when you're in neutral, so it should be left in "Drive" even when you're stopped at a light.
 

·
Registered
Joined
·
1,028 Posts
Correct, the battery will NOT drain until you run out of gas. How low the indicator goes seems kinda variable. On mine the engine usually starts when it gets down to 2 bars or 1. The A/C runs on electricity which is drawn from the battery; but again, when the battery gets low the engine starts up to recharge it.

To be crushingly explicit: this means one should not normally sit with the car in the IG-ON position (orange light in the START pushbutton) or with the shift in "N". Either of these will NOT allow the engine to start, and then you CAN drain the battery. That Would Be Bad. Just turn the car on normally at the start of any drive and leave it on until you leave the car; let the car take care of itself regardless of how long you may find yourself waiting at a railroad crossing, or whatever, and don't worry about it.
 

·
Registered
Joined
·
112 Posts
Just to clarify / boil down a bit:
_
The car will take care of the battery if you're in READY
but not in Neutral. You may get down somewhere into
two-pink-bars territory, but the ICE *will* fire up
at the appropriate time and deal with it.
_
[Go stealth slowly around an empty parking lot for
a while to deliberately run it down, and
you can observe this for yourself.]
_
For waiting in traffic, moving to "Park" might be easier
on your foot. The same automatic caretaking will happen.
No reason to hold the brakes and put more mileage on all
those solenoids and the circuits that power them if
you know you'll just be sitting there.
_
_H*
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #10 ·
battery questions

Thanks all
No, I was not in "N". I'm a Prius newbie and am panicked to even go near "N".

I'm am, however, confused about IG-ON. Is this the same as most other cars in "ALT". I'm not sure what IG-ON is for except to play the radio in my driveway.

Also (Hyperion). What is MFD?

Thanks
 

·
Registered
Joined
·
1,661 Posts
Re: battery questions

drtravel47 said:
Thanks all
No, I was not in "N". I'm a Prius newbie and am panicked to even go near "N".

I'm am, however, confused about IG-ON. Is this the same as most other cars in "ALT". I'm not sure what IG-ON is for except to play the radio in my driveway.

Also (Hyperion). What is MFD?

Thanks
MFD = multi function display (the monitor on the console)

if you don't put your foot on the brake when you push power to turn the car on, you get accessories only - not "go" power. The battery will operate "stuff" for a while, but the ICE (internal combustion engine) won't come on to charge the battery. That's the "orange light" power on mode. The green light power on mode is the one that will let you move the car. If you aren't in N, the ICE will come on to charge the battery if you get low. :)

It's a happy little car. Don't get nervous. Get giggly over it. And enjoy watching how great your mpg are. Sort of like a video game, where you compete with yourself to get higher mpg. High score wins! And it's always YOU! YAY!!

:D
 

·
Registered
Joined
·
1,233 Posts
IG-ON is the same as "ON" on regular vehicles. All accessories work (i.e. radio, power windows, A/C, fan).
 

·
Registered
Joined
·
7,161 Posts
Now let ME clarify.

There are 4 power modes on the Prius:

Off - I'm sure you know this one.

ACC - To get here push the power button without pressing the brake. LED indicator will be green. This will operate the radio, the power outlets, the MFD, and the NAV. That's about it.

Ig-On - To get here, press the power button two times while not pressing the brake, or once if already in ACC. Indicator will be amber. Almost everything is powered up. You have the cabin fan, but no A/C because the HV battery is still turned off.

READY - To get here from any other mode, press and hold brake, then press power. LED indicator is off, READY is shown on the combination meter (speedometer area). System Main Relays will engage to connect the HV batteries to the inverter. Everything works, and you can drive.
 

·
Registered
Joined
·
1,233 Posts
Dan? Question.

I left it at IG-ON once when I was cleaning the interior and doesn't the battery display go on in IG-ON mode? Cause I swear the battery dropped from 4 bars to 3 bars while in that mode. In that case, wouldn't there be A/C available since it's running off the electric inverter (as if the engine's off at a stoplight)?
 

·
Registered
Joined
·
7,161 Posts
Ig-On does not allow the system main relays to engage. Without those relays, the only thing connected to them HV batteries is the voltage/temp sensors from the HV battery modules to the HV battery ECU. Because the HB battery ECU has direct connection/monitoring of the modules even with the system main relays off, you can get an accurate SOC display.

Because you don't have high voltage going to the inverter, you can't have the AC compressor run. However, the cabin fan runs on 12V so it can and is powered by the Aux battery.
 

·
Registered
Joined
·
46 Posts
That sure was a lot of discussion to tell drtravel47 just to drive normally and not worry about it.
 
1 - 19 of 19 Posts
Top