PIP does not charge the plug in battery while driving

Ok, hadn't seen this part

No, there is no resistive dump in the Prius as you might have in a wind or hydro system where generation exceeds demand. You are correct that the system does need to have ways to protect itself from being overcharged. As I understand once the battery is nearly full, it uses more friction braking power (hence the hot wheel wells) and goes into "engine braking" mode using the ICE at elevated RPMs to dissipate any surplus power generated.

Rob

 

The ICE qualifies as a "resistive load that has either air or liquid cooling involved". Or am I missing something else?

It would be nice to have an electrical resistance heater in the PiP for cabin heating, or ICE pre-heat, that could beneficially harvest such excess energy. I know there are some people that are put off that the ICE has to burn a small amount of gasoline to heat the cabin.

 

In no way am I "calling Toyota Stupid" in my post, in fact I think Satoshi Ogiso and the Engineers developing their Hybrid lines border on brilliant. However in reality intense heat does produce wear and tear on all man-made systems.

You are making a great leap of distortion from the facts and opinion I stated to assume a reference to Toyota Engineers being "stupid".

By your member info you indicate that your are a 2004 Prius owner so your post may or may not have direct personal experience on how a 2012 3rd generation + Plug In Prius manages it's heat.

I have no relevant experience on an early second generation Prius so I can't comment on them. As you are from southern Orange County you may or may not know that in California both the 2004 and 2012 models have a 150,000 warranty on the battery so that is not my concern. The other components however do not, so why stress them unnecessarily if you have a choice?

That was my whole point.

 

If the battery is full, and you have excess energy, where else can it go other than heat? It may go into engine compression braking (basically, creating hot air), or it might be the friction brakes, but either way, you are discarding the energy as heat. Unlike diesel locomotives, the Prius does not use resistive coils to dissipate energy. (OT: with trains, there are two braking systems. The locomotive itself reverses the electric drive motors to generate electricity, but, unlike the Prius, there is no place to put it, so the electricity gets dumped into resistive coils on the top of the locomotive. The cars use air brakes. The engineer can apply either or both as the situation warrants.)

 

Thanks to Rob and others for clarifying about the diversion to normal friction braking after the
"Battery Tank" is filled up from regeneration.

Good analogy by Charles to diesel locomotives, I have always been fascinated with these behemoths and how they handle the big downgrades...

I was using the Engine Braking function a lot after I fully charged also. I guess using the old school friction brakes is just unavoidable in such extreme downgrades. I just try to avoid them at all costs in normal driving cause I don't like to waste a Watt of regeneration to old school friction brakes if I don't absolutely have to...

Coming down the Rockies probably was a good use for the Engine Braking position if there ever was one.

 

oh sorry I thought you were saying the traction pack and inverter, or the MG's start to heat up (instead of simply disengaging) as in maybe they'll melt the traction pack ... there seems to be so much misinformation here on this thread ... and a lack of understanding and presumptions ... that I presumed the worst, at that point. Thank you for restoring my faith in some PiP owners


SGH-I717R ? 2

 

Agreed. Its worth noting that the Prius will effectively use this "B" mode once the battery is nearly full whether the driver has selected it or not. In the early PHEV conversion experiments it was found that if the add on pack pulled the stock pack voltage/SOC too high the car would basically enter "B" mode to burn off the extra charge.

Rob

 

Coasting downhill, or even briefly, also charges the battery. Compare (carefully!) the difference between how a Prius or any car coasts when in gear (D) compared to Neutral. Substantial difference! On a Prius, the drag you feel is the transaxle recharging the battery. On an ordinary car, the drag is the transmission spinning the idling engine.

 

Never mind, this was already answered above.

 

That's true for the Prius. The excess electricity go out through the engine compression brake (B gear) or the friction brakes.

From what I've read, Volt actually use the excess electricity and generate heat in the inverter. The coolant and radiator dump it out into the environment (air). That's one expensive brake to warrant.

 

You need to update your profile to include your new ride.

 

lol, I was just thinking the same thing

 

Here's another real-world example:

I had only 0.2 mile left as I approached the intersection. I pushed the HV/EV button just as it dropped to 0.1 mile. The engine fired up as I was coming to a stop...

0.1
0.2
0.3
0.4
0.5
0.6

I watched the EV mile estimate climb as the engine warmed up, just sitting there motionless waiting for the really long light to finally turn green.

 

It's not going to fully charge EV. It's going to give you maybe a mile then kick into hybrid mode and discharge that 1 mile or so of EV. Then cycle again.

 

But I think he is showing that you can charge the traction battery from the ICE without the car moving (not using kinetic energy).

Does that 1 mile show up as EV or HV on the display?

 

yeah, like a non plug in prius

 

See " Prius plug in batterVS Nissan" Post # 17

 

It's called force charging, cannot be done on the PIP. Niether EV nor HV