05 prius rpm jumps

How long of a downhill? Does your HV battery SoC go all the way to full green?

Tom

 

If the SOC hits full green (all bars filled) while going downhill, the engine ICE starting and possibly revving to high RPMs (possibly 2000+) is normal. It's apparently to keep the battery from getting overcharged.

I encounter this around where I live now due to a steep descent and can monitor the ICE RPMs and HV battery SoC, thanks to ScanGauge. It'll tend to happen ~75% or slightly higher SoC, which is represtened on the MFD as all filled bars.

And no, all filled bars does NOT equal 100% SoC. Someone figured out the mapping and posted it at http://privatenrg.com/#Full_SOC.

 

Yeah you're going downhill for 1/2 a mile so you're regenerating a fair bit of energy. Then you have to slow down for the roadworks and there's some more regeneration. So yes it's extremely likely that this is just the regenerative system dumping excess energy once the traction battery is full.

BTW. This is nothing abnormal. Many of us here that drive in hilly terrain have seen this happen once or more. Just take a look at the batery charge display next time, it happens if you get all 8 green bars and then still need to brake some more.

 

Did the RPM stay up indefinitely or did it come back down after a short time? If the latter then it is very likely just that when you passed the "hump" in the road, the traction control kicked in to rev the engine to save the MGs. So no worry. Good luck!

 

That is because at the bottom of the hill when you press the go pedal the car suddenly has an outlet for that excess energy stored in the battery - and that's doing what it's designed to do, to power the car! So it uses the battery energy to propel the car instead of trying to waste it by spinning the engine as an air pump.

It's all 100% logical and 100% normal. Just take note next time if the battery is at a full 8 green bars when it happens, then you'll really know for sure.

 

Mine did this same thing but all the warning light. s came on until I stoped and then just the red triangle and check engine light was on until cleared at dealer Is that normal?

 

If the lights came on, that's not normal. Since it is summer-weather in most of the northern hemisphere now, have you had the inverter coolant pump recall done?

 

Yes I have . Tonday it felt as if the regen were coming and going. Sort of a seat of the pants drag you know

 

Well what codes did the dealer pull? It should be on your receipt/invoice.

 

aop92 //606