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Hybrid Battery Level Drops to Only 1 Bar...Then What?

Discussion in 'Gen 2 Prius Main Forum' started by mrhummer3, Mar 22, 2004.

  1. mrhummer3

    mrhummer3 New Member

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    I would like to know what happens if the Hybrid Battery Indicator on the Energy Monitor drops down to ZERO segments showing? The 2004 Owner's Manual does not cover this situation.

    Recently, I was on a cross-country highway trip from Oklahoma City, OK to Las Vegas, NV. I had been climbing in altitude all day long, very gradually. By the time I had reached the New Mexico state line, I had already climbed about 4000 feet in elevation over the prior 350 miles.

    Once entering New Mexico, the speed limit went to 75 mph, so I set the cruise control to this speed. The car had no trouble maintaining it, but I did notice that much of the time, BOTH the gasoline engine AND the electric motor were needed to maintain the speed limit.

    The outside temperature was arounf 89 degrees F and as such, I was using the A/C. I also had my headlights switched on for safety.

    What I began to notice was a gradual, steady decrease in the Hybrid Battery level. It went from 4 segments...to 3...then to 2...then to only 1! This occurred over a period of about 1 hour of driving at the 75 mph speed limit.

    When the indicator got to showing only 1 segment, I got worried. I did not know what might happen if it were to drop down to zero segments.

    I switched OFF the cruise control and switched the A/C from AUTO to a fan setting of "1" and increased the temperature setting a few degrees warmer. I also switched OFF my headlights and reduced my speed to 65 mph...some 10 mph below the speed limit.

    After doing these things, in about 30 minutes the battery level went from 1 segment showing up to 2 and remained there.

    This had been a scary situation as I did not know what to do had the battery level continued to drop. This is not covered in the Owner's Manual and really should be.

    I live in Las Vegas, NV and to drive to Los Angeles, I have to drive over two mountain passes where the climb in altitude is over 5000 feet over a 25 mile stretch. In the Summer, the temperature can easily top 110 degrees F, so using the A/C is a necessity.

    Can I expect the same thing to happen to me again? What would happen if the hybrid battery level dropped to zero segments? Shouldn't the vehicle be able to maintain the posted speed limit (70 in Nevada and California) while running the A/C at a comfortable level?

    Please advise, as I am afraid to take the car on this trip next time I need to.

    Thanks
     
  2. olends

    olends New Member

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    do not fret. the car will take care of itself. and even though the display shows 0 bars there is actally 40% left in the battery, sort of like the gas tank
     
  3. xlarimer

    xlarimer New Member

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    I went up the grapevine (Southern California) on my 04 prius' madien voyage and TRIED to get it below 1 (Running it at 90+ MPH). It did it for a second but it was so quick that I almost couldn't be sure. But as soon as it hit that the software (HSD) makes no power come from the battery. The engine immediately charges the battery at almost all costs after that. If one punches it, all ICE power goes to forward momentum and charging ceases but as soon as the burst is done, it is charging up a storm until right inbetween 1 and 2 bars where it acts like it can give KWH power again.

    Hey, it's for science right? I guess I was lucky since a) cops patrol the area there, B) it was snowing when I went over it, and c)I had no plates or registration at the time (actually I still don't. :))

    Of course, on the way down, the battery was overcharged. ;)
     
  4. edmcnierney

    edmcnierney Junior Member

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    Don't worry. Be happy.

    It's not covered in the owner's manual because it won't happen and there's nothing to worry about. If it does happen it's because there's a serious malfunction, and the owner's manual can't be expected to list every possible malfunction (e.g. "Page 123,993 - Cylinder head exits left side of engine compartment").

    What will really happen? Shutting off the lights, A/C, etc. will let you go a tiny bit faster under ICE-only operation. If you hadn't done those things the outcome would have probably been exactly the same, except cooler and better-lit.
     
  5. rockluvr

    rockluvr New Member

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    Driving up steep inclines such as in mountainous terrain will deplete the charge of the battery - at least on the energy monitor. I drove from Denver to Evergreen (west along I-70) in Colorado. When the battery gets low, the last blue bars turn pink and then disappear. I also was a bit worried as I was still climbing up on the freeway. However, no need to worry - what happened was the ICE kicked on to charge the battery. No difference on performance of the Prius that I could tell - I was still going 65 mph. On the return trip going downhill for several miles, the battery completely charged - all green bars including the normally white bar at the top. That trip was a few weeks ago and I don't see anything different about the car. Surprisingly mileage on that trip was ~50 mpg.

    Today I am leaving on a trip from Denver to Grand Junction, CO (on the western slope over the continental divide). I'll report back how that goes in a few days. I agree that the manual should have mentioned the various states of charge of the battery as it was worrisome at the time.
     
  6. rflagg

    rflagg Member

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    As an aside, I find it great that this car is able to change your viewpoint (definately mine, anyways), from pushing the car and not worrying about it - driving on bad tires, pushing the engine, oversteering and braking, etc - to where we actually care and worry about the car because of the feedback it gives us.

    I've gone from driving a neon and only paying attention to it when it wouldn't start or something broke on it, to being someone who tries to achieve the highest mpg possible, someone who is more aware of his surroundings in order to prepare for stopped traffic, and so on. I think the Prius, and other cars similar in it's design, are able to turn us from a group of car-abusers into a group of car-lovers.

    -m.
     
  7. Sev

    Sev Junior Member

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    Not quite the same situation but similar. Perhaps someone can explain what happened or didn't happen and why. We were sitting in a restaurant parking lot eating some sandwiches since we couldn't eat in because we had our dogs with us. We had the radio and air on for comfort. (Temp was in the upper 70's, but dogs were panting) The Prius was in Park. As we ate, we watched the screen as the battery charge went from 6 blue down to 2 pink. Expected the ICE to come on to charge the battery. It didn't. We got concerned when it didn't come on for at least 5 minutes while in this pink condition. We decided to drive the car to charge it up even though we weren't really ready to leave just yet. It charged up quickly, back to 6 blue within just a few miles. Why didn't it come on while we were in Park? Would it have come on at 1 pink bar? Should we have worried?

    Thanks,
     
  8. daniel

    daniel Cat Lovers Against the Bomb

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    Just my opinion: No. You should not have worried. The ICE would have come on when the computer decided it was time to charge the battery.
     
  9. xevious

    xevious New Member

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    More aggressive use of the battery was one of the major design improvements of the 2004 Prius. In the classic, the ICE would cycle on and off at fairly short intervals if left in park (ignition on, A/C off). I've noticed that the 2004 Prius waits until the useable SOC of the battery is nearly depleted before turning the ICE on to recharge.

    A huge practical benefit of this is that we can get long periods of battery-only A/C in the city. When the battery is depleted, the ICE turns on and quickly replenishes the charge.

    Don't worry - just drive -er- sit in it!