I've only caught this a few times, the first several years ago in a trip through Chicago. It seems to happen less than once per year. The first time it happened and I saw the state-of-charge on the ScanGauge climbing up into the 90s and charge current still flowing, I was a bit afraid there was some bug and it was self-destructing, but it just pushed the charge up really high, held it there a couple minutes, then pulled it back down again, and it all seemed like something done "on purpose". This time I was at a stop light coming home from work when I glanced down and saw the state of charge at 70+ and something like twelve amps still going in, and I thought, instead of going straight home, I'd head out of town for a nice fall colors drive and see what it did. All my way out of town, it pretty much kept a steady 8 to 12 amps going into the battery (accelerating like a dog, because that's a noticeable extra load). I snapped this at a stop light when it had hit 96 and still charging at 8.8 amps: On this trip I never saw it exceed 97, but it hit 97 and stayed there several minutes. I had some accelerations and hills where it had to use power, and dropped back to 94 or 93, but as soon as I hit level it would pour on the charge current again and push back up to 97. Right around 6:15, just about 30 or 40 minutes into the drive, it switched to rapid discharge, pulling a sustained 20 to 50 amps out of the battery, just in normal flat 45 MPH driving. Interesting about this phase was that it refused to put any charge into the battery, even during slowing or braking - all diverted directly to engine braking the moment my foot came off the accelerator (much like normal "B" behavior, except I was in "D"). As soon as it was back below 65%, which took less than 5 minutes at that rate, that mode was ended and it just behaved like a perfectly normal Prius the rest of the way home (except the battery fan was running for a lot of the way). The leftmost bar in this graph is part of the period when it was putting heavy charge into the battery. The second to rightmost shows the five-minute period that used it all up again. While this is maybe the third/fourth time (in eight years) I've caught my car doing this, what's interesting this time is this seems to be part 2 of a sequence that started a couple days ago, when I was again on my way home from work, glanced at the ScanGauge and saw it sucking the state of charge right down ... 50 ... 40 ... 30 (huh?) ... 20 (?!?) ... seemed to hit about 15 (a number I don't think I've ever seen before as a SoC), making me a little nervous about stopping the car, as I had heard below 20 it may not elect to start, but then it turned right around and steadily recharged to the normal range. Then this afternoon it seemed to follow up with the high-SoC end of the process. I had never seen the discharge-to-low-SoC end before. -Chap
Like many Priuschatter's, your '01 seems to have an opinion as to whether grid charging is legit or not!
It would make sense that it does this from time to time. I for one noticed a few months ago, that my vehicle let the battery fully charge for the first time ( I am the only one that drives it). Looked at my display and there it was, all bars full. Never happened before, and hasn't happened since.
Mine went up to a 100% charge last weekend when I was using the "B" gear down a fairly long hill and then went down to about 3 bars in town. It stayed there for a little while and then went back up to about 80%. I see people on here that say they have never had their charge up to 100% but mine has been there about 3 times in the about 3 months I have had my 2010 basic Prius and I have only put about 1500 miles on it. I have read that it should operate at about 80% so I don't know if mine was going through balancing and I don't know if going to 100% so often is good for it. I have to go down the long hill to get to town and I always use the "B" to keep from riding my brakes.
Are you sure it was 100% charge and not just 'full battery icon' which is just 80%? How did you measure it? @Eclipse1701d what you are describing is not cells balancing. Battery icon bars full is only 80% SOC.
Yes, it was just all the bars, I thought that meant 100%. Thanks for the info. Do you have to put some kind of tester on them to detect 100%. As you can tell I'm a newbie to this and not very techno oriented.
I just had another thought is that if that's 80% my bars are usually at about what looks like 6 bars if there are 10, is that Ok? Thanks.
6 bars (out of 8) is roughly 55-66.5% state of charge and is the happy spot the car attempts to maintain most all of the time. Have a look at this SOC chart: http://privatenrg.com/ComplexSOC.jpg
Don't have vci or scangauge. I drive about 17,000 miles a year, and at just under 42,000 miles, the battery indicator went full, for the first time. So, I digress. It was not 100%. I just found it odd that it indicated full battery. My driving style and location hasn't changed, so that was new for me. It was not caused by a hill, or out of the ordinary regen... As I continued to drive, it indicated full battery for a little over a minute. Has not returned to that condition, since.
My light-blue 2002 finally kicked the bucket this week after my college-age niece ran it into a guardrail (she's fine and no other cars were involved). So reminiscing these last 24 hours, stumbled across this old thread and yeah, remember observing this back in 2010 on my ScanGauge and not knowing what was going on... I guess it's pretty rare to actually witness one of these events. Runaway charging event? | PriusChat
Well just by total coincidence, I happened to buy a Tesla Model S last week for myself, so I'm good for now But yes, my niece is the one who's car-less, and while we're debating whether she deserves a replacement car at all, the first thing I did was look on Craiglist as I knew there'd be a bunch of 2001-2003's available here in California for relatively cheap. And they basically can last forever with proper care and maintenance, not to mention I now can recognize most of the common failures to get the car back in service. Not to mention it's proven to be very safe for the occupants in a crash as well, which gives us some reassurance. So either another 1st gen Prius, or maybe a Leaf...
Some senior lessons I've learned about cars for young people. If they're buying a car themselves, I don't offer advice unless asked. If I'm buying it for them, my choice is the final vote. If the kid needs a car, a Corolla or Gen 1 Prius will do. Cheap to insure, own, license, maintain. And they kinda have character. If I buy the car for them, I expect them to insure maintain the car--and provide proof when I ask for it. It;s in the kids name, but I keep the title so they can't sell the car or get a title loan on it. I don't do cosignatures. I'm not a bank.
