Fit the first time ever, I hit 8 bars last night. Kinda took me by surprise. I thought that was as rare as hens teeth I live in a hilly area. Other than the freeway, you can't drive more than a few blocks without being on some sort of grade. Many are hills. For this last tank, I've been trying out Normal mode to see if gas mileage improves, in place of my favoured Pwr mode. Suddenly - POOF - 8 bars. Didn't expect that.
8 bars is not good to see, shows a possible weaker module getting full quickly. I see that more often with my 2010 now
I see 8 bars more often in cold weather than in warm as the engine is running for cabin heat, and with nothing better to do, it charges the battery. In Summer, I see 8 bars coming down long hills on trips, as there are no long hills locally.
Long enough hill, it should happen regularly, Say maybe a kilometer. I've noticed with full bars, the car will keep the engine off, even if you sneak a bit above the median, as displayed on the Hybrid Synergy Display.
Ok, cool. You guys don't seem worried about that being bad for battery. (But let me know if it is.) This did occur at the end of a long 1 or 1.5 mile down grade that I go down regularly. If it's an issue, I could adjust. Is there a way to test for that? Is there a way to be gentler on that module?
You should be able to 'fill' the Prius battery braking down about a 600 foot vertical drop, that is normal. The car will endeavor to use that power soon, so there is room for more regenerative braking.
I see 8 bar all the time.like every 3 days .Should I be worried ?I am from new england so its cold outside now. Posted via the PriusChat mobile app.
Saw 8 bars 4 or 5 times in each direction today on a round trip from Queensbury, NY to Putney, VT. Completely normal for any Prius operating in moderately hilly to mountainous terrain.
When commuting in my 2010, I would usually see 8 bars by the base of a 400 foot descent, depending on how full it was before. The descent begins almost immediately from my house, so the engine was still warming up through that portion. Winter season made 8 bars more reliable. I traded for the 2012 after my commuting career was over, and that is no longer the predominate route away from my house.
I don't think that's a problem since the system stops charging I think at 80% or 60% of battery capacity so you will never overcharge it but it will still show you 8 bars.
Excess energy goes into either engine friction & compression, or disk brake friction. Depending on weather, you may also be able to divert some of it into cabin cooling with AC, or resistance heat for window defrosting.
Do you mean the energy that would have gone into charging the battery? That's basically the car taking advantage of the downhill inertia, using it to turn the electric motor, and charge the battery. So now it's stopped doing that, due to the sated battery. And you want to continue to slow the car, prevent runaway? Then when you step on the brakes it goes back to old school: friction brakes are the sole braking power, and heat builds up. I guess that's where the energy goes. Plus the engine braking, employing engine braking, especially when you're in B mode.
Well, no BIG deal here, but to be clear: I've got 8 bars. I'm going down hill. If I DON'T touch the brakes, the HSI would still show regenerative braking, wouldn't it ? So....I'm going down hill, the wheels roll, but they also generate a little electricity which usually goes to one of the batteries. But Toyota doesn't want that battery getting any more than 80%. The computer disconnects a relay or whatever, and extra juice no longer goes to the battery. So where does that extra electricity go ? Once again, just curious.
I'm thinking that extra electricity is not produced to begin with. Normally, coasting downhill, there will be a slight drag, as the electric motors are engaged as generators. Full battery: that stops happening. If you want to slow the the car you're using friction brakes, and/or B mode.
Well that would explain it. Cool! So, once battery hits controlled-max, the electric motors just dis-engage from wheels - no more regeneration. Makes sense.
When my battery is truly topped off, (to the computer set limit, not the higher battery rating limit), my HSI display shows no more regeneration. But beware that 8 bars, and really full battery with no more regeneration, don't happen at the same moment. Think of the SOC display as rounded to the nearest whole bar. When the internal number reaches 7.5 bars, the display rounds up to a full 8, even the some regeneration is still happening and some charge is going into the battery. Just note that the HSI CHG bar is getting shorter, and this situation doesn't last long until the battery is really full. Note that the disengagement is just in the electrical control of the motor-generators, which also causes back-torque on the MG shaft to drop to essentially zero. There is no mechanical disengagement.
I have the same kind of question. Living in the mountains here. When we come out going downhill winding down over 1,200 feet My battery will fill then I hear this awful noise . . . like a high RPM engine in Low gear. What I have learned is if I use my Cruise Control, (35 mph ) it will hold my Prius back and NOT runaway. NO NOISE. Any Ideas?
