i got my prius on January 2. The battery level indicator almost always had mostly blue bars. It didn't change much, it was about 2 bars less than full. Sometimes it would go down a bar but that's about it. Once in a while it would completely fillled with green bars. I read posts in this forum that said it's normal for the battery charge indicator to go lower than more than half filled with blue bars, but mine never did. After I had the car about a month and a half, i took it to the car wash by my office. There was no line, i was first, and only one car behind me. They took my number and said they would call me when it was ready. My office is next door, i went back to the office and got busy. About an hour later, i figured my car would be ready, and they probably forgot to call. I walked over and found that the guy was just bringing my wet car out of the wash tunnel and had not yet begun wiping it off. I was annoyed about this, i didn't know why they would take so long, they never had before. I went back to my office, got very busy, then an hour later, i went to get my car. It was done and parked. I got in and drove down the alley to the parking structure for my office, and was shocked to see the battery charge indicator was at one purple bar. I didn't even know they had purple. I couldn't find anything in the user manual about it. I called a dealer, my agency that i had gone to before. I told the service guy what happened and asked whether that was a serious problem, and if it was about to go dead. He was very abrupt and said i would just have to bring the car in. I asked a couple of questions to see if i could just get an idea of what those bars meant, but he continued to be abrupt and impatient, and insisted i would have to bring the car in. I realize this probably means he has no clue what the bars mean on a Prius. I then called the Toyota customer service number to ask for tech support on this issue. I got a rep who was very very nice, friendly, and said that the reps were not able to provide any technical information, but could refer me to a dealer. I explained that the man i talked to on the phone would not give me any information or even talk to me, just saying i had to bring it in, but this was late on a friday afternoon, i live a long way from home and from that dealer and i wasn't sure if it was ok to drive the car at all, or what to do about the battery appearing to be run down. She then put me on hold and after a while she came back, she had researched the issue and gave me useful information, including reassurance that the car was OK, she told me what the bars meant, and she said i should just go drive it around for a little while with all the power things turned off, which i did and in less than 10 minutes it was almost back to normal. I was still worried though that something happened at the car wash to damage my car. Since that time, my car easily goes low in the bars, i get the purple bars in a short time, sometimes when i'm driving, which surprised me, and also, i have for a long time eaten my lunch in the car and listened to the radio, it's relaxing, quiet, private, a break from my very intense job with lots of people and their demands and needs etc. So, now, when i sit in my car at lunch, it seems whether i keep the ignition on or just the other stuff but not the motor, it doesn't matter. In about 10 or 15 minutes i have two purple bars. I am pretty sure this wasn't happening before. Before i turn the ignition on at lunch, i first turn the headlights off and no other power is running except the radio. This is alarming to me and i feel bad that my car never did this until that day they inexplicably kept it at the car wash for about 2 1/2 hours. Shouldn't i be able to sit in the car at lunch listening to the radio for less than a half hour without the charge going down so much? I realize (from reading posts) that one bar still means it has 40% charge, which is reassuring. But is this OK?
I'm not sure my car is "normal", but my charge goes all over the place, from one purple to eight green. My mpgs are good, so I don't worry about it. Regards, Dave
The car wash left your car in N for a long time. In N the ICE can't recharge the battery, so the level drops. As Evan says, it's completely normal and not damaging. You would expect the dealer to be able to tell you something simple like this, but they aren't the sharpest bunch. Tom
+1. They left your car in N while it was going thru the wash. I had my car aligned and the shop also left my car in N for about an hour with the same result, the battery was showing purple bars.
thanks for all the reassuring replies. Is it normal for it to go from 6 blue bars to 2 purple bars while i sit in the car listening to the radio for about 20 minutes while having a quick lunch? i didn't think it ever did that before, until the thing at the car wash? What's the right or best way to sit in the car for a period of time, less than a half hour, without draining the battery a lot? I don't know the right words to ask this. OK, Is it better to leave the engine on, or to turn the engine on, by putting the foot on the brake and hitting Power twice, or is it better to just hit power twice without putting foot on brake, i hope that made sense. In my previous normal car, Accord, when i ate lunch in my car, i would just turn the key to the second knotch, without engaging the starter motor. I wouldn't turn the engine on. There was never any evident stress on the battery from doing that, just listening to the radio, nothing else on. On rare occasions when it was extremely hot, i would turn the engine on so i could run the AC too. What is the right way to sit in the car listening to the radio for under a half hour, without any bad effect on the battery?
If you just want to listen to the radio during lunch, then press the Power button once with your foot off of the brake pedal. This will put the car into ACC mode; you can play the radio, but you can't run the AC, power windows, etc. Make sure to turn it off when you are done by pressing the button twice more with your foot off the brake; the first press is IG-ON mode, the second press is Off. If you want to run the AC while you sit in the car, you should put it in Ready mode (press button with foot on brake). You can leave the car in P and the AC can run off of the HV battery. When the SOC (state of charge) gets low, the ICE (internal combustion engine) will start and run to recharge the battery as needed.
You live in Colorado. If you do any mountain driving, your SOC will routinely swing from purple to green. If you are driving across Iowa, it won't swing as much. Tom
Thank you so much for explaining this in such detail. Thank you for telling me what the words for these things are. BIG help.
I would agree, they probably left your car in Neutral with the power ON. The engine won't kick in to charge the battery system. If you're going to stop for lunch in the car, putting it in park (remember to set the parking brake) should be fine for a short while. If you're going to be at a stop for a longer time, power off the car, then hit the power button ONCE with your foot off the brake and you'll be able to use the stereo. I still have yet to see my charge indicator go below about three bars from the top, but I've only had the car a week. Summertime will likely tax it more with a lot of AC use!
It runs from the small 12V battery. After an hour it shuts down automatically to help save the battery. You can restart if you wish, but keep in mind that it is a small battery. Tom
Thanks for all the info on the battery level and what the bars mean. Mine seem to go down faster than they did before. Maybe i just wasn't paying much attention before. But i didn't know that if i pressed the power button one time, i could still run the radio. I did that today. The bars still went down pretty quick over a half hour period, but from what people are saying, i understand it won't result in my car being dead and unable to start. That was scaring me.
Just to make sure I understand this last post, let me make a clarification: pressing the power button one time and listening to the radio will NOT cause your HV battery bars to drop. I found your post a little confusing in this area. When you press the power button one time, the HV battery remains isolated. Only the 12V battery supplies power. Later, when you power up completely, the HV battery and/or ICE will start recharging the 12V battery. In that respect it can cause bars to drop, but only after running for a while. Are you saying that your HV SOC drops while the car is powered off? Tom
Let me take one more crack at this: ACC mode: 12v battery supplies power to the radio and a few other accessories. Meant for listening to radio or checking the display on the Nav. There is an automatic timer that will turn ACC mode off after an hour to save the 12v battery. The HV battery is disconnected by the system main relay(s). IG-On mode: 12v battery supplies power to most of the 12v systems including engine sensors and power windows. Meant for troubleshooting vehicle systems. You can also operate the power windows and the AC fan will come on (but the AC compressor doesn't operate). Don't leave the car in IG-On for an extended time; it will drain the 12v battery much faster than ACC mode. The HV battery is disconnected by the system main relay(s). Ready mode: The HV battery is now connected via the system main relay(s). The DC to DC converter supplies 12v power to all accessories and supplies power to keep the 12v battery charged. The ICE can start and stop as the car commands to charge the HV battery. The ICE can charge the HV battery in any transaxle mode except for N. N disconnects the electrical connection between the HV battery and the transaxle. The AC compressor can run using power from the HV battery. And of course, the car can be driven. Off mode: The HV battery is disconnected by the system main relay(s). The transaxle will be shifted to P if it isn't already in P. 12v power from the 12v battery is not available to any 12v accessories, but only available for a few essential functions like Keep Alive memory for the Engine ECU and Anti Theft.
yesterday was the first time i tried it with just the ACC on. I did notice that i couldn't operate the windows so i turned it on to Ig-On mode in order to open the windows (thanks Dog Friend for the terminology and clear detailed explanation). Then i turned it off and back on to ACC to listen to the radio. I will need to do this again and pay more attention, but i thought that when i turned it to Ig-ON, it had the usual 6 blue bars, and after lunch, 20 minutes or so later, when i went from ACC to Ig-on again, it was down one or two bars, and i anticipated that if were to remain in the car another half hour it would continue to go down. Given what you're saying, i understand that's not possible, so i need to try it some more and pay more attention to the sequence the details of what i did. Assuming as i did that the bars could still go down in ACC mode, i just assumed they did. But maybe, there must be another explanation, so i have to pay more attention next time. I just thought to myself at the time, that the bars seemed to start going down almost right away, and wondered if that was normal. but now i'm not sure what happened.
The bars will change a bit from shutdown to startup, but not because the SOC changes. The mechanism used to measure the battery SOC is not perfect, and can be fooled a bit. It resets over time. Don't worry about a bar or two. If you consistently drop a lot of bars overnight, then you might have a problem. Tom
The easy way to listen to the radio in the Prius is to leave the car ON ("Ready", as though you about to drive away) and in "Park". That way it operates completely normally, starting the engine as needed to keep both of the batteries charged up. Of course you don't want to leave the car ON for more than a minute or two if it is parked in a completely enclosed space with no ventilation to remove the engine exhaust. In that case shut the car OFF and go listen to the radio in the house. If you do not pay attention ACC and IG-ON *will* drain one or both batteries.
