Regenerative Charging - Coasting Feel

[Altitude]

I know that the hybrid battery recharges during driving and I’m curious about how it feels. I drove a Rivian the other day and experienced single-pedal driving for the first time other than in a golf cart. It’s not objectionable but very different than ICE vehicles.

I’m sure the regenerative charging effect is nowhere near as obvious in these Land Cruisers. But I am curious about it since I do a great deal of mountain driving up and down extended grades.

What does it feel like? Would anyone say that the effect is impactful enough to limit speed on a downhill such that you don’t gear down as much? Or is there no effect at all in coasting and only through braking?

 

[DenisLM]

Drives like a ICE car.
Actually kinda worse because with the small engine there's not much engine brake.

 

[Tripod1404]

It is a hybrid, so the amount of regenerative breaking is controlled by the break pedal. So it feels similar to other ICE cars as the electric motor does not create counter resistance unless the brake pedal is depressed.

On a fully electric vehicle with one-pedal driving, regenerative breaking is set to the max amount that the battery can accept at any given moment (which is high since the battery has enough capacity to store electricity needed to power an average house for 3-5 days). Therefore such systems work well on electric vehicles due to much more powerful electric motors and much higher battery capacity (compared to a hybrid), which makes regenerative breaking comparably more efficient.

 

[EOD Guy]

I can't hardly tell other than sometimes it feels like the brakes are fading, so you press harder, then all of a sudden, they grab. It has been an adjustment for me.

There is a U-Tube video out where they actually tested the regen on the LC and they were less than impressed with the regen braking on a mountain decline.

 

[xeontis]

Well I have a BEV which I use 1PD (one pedal drive) I love it and I have no issues switching between vehicles that don't 1PD. The LC is an odd potato in that the brake pedal is somewhat inconsistent which can be disconcerting. Sometimes I come to a stop then for some reason it starts to roll and I need to press harder. Sometimes it acts just like every other ICE I've driven. Sometimes it while braking it "brakes" harder then suddenly it doesn't and feels like it releases then I have to brake harder. This could be a combination of regen and nannys.

 

[Tripod1404]

I can't hardly tell other than sometimes it feels like the brakes are fading, so you press harder, then all of a sudden, they grab. It has been an adjustment for me.

There is a U-Tube video out where they actually tested the regen on the LC and they were less than impressed with the regen braking on a mountain decline.

I wish electric motor gauge had an opposite direction to show how much regenerative breaking is being applied. They have this on their regular hybrids where the gauge is split between Charge/Power. It is very helpful if one wants to apply just enough pressure to slowdown or maintain speed downhill without maxing regenerative breaking.

 

[Markarian421]

I love the one pedal driving/regenerative braking on our plug in hybrid, but yes as @Tripod1404 points out that's only really possible when you have a large battery. I'm disappointed to hear about the Land Cruiser's odd braking behavior when it's coming to a stop, but that does sound a lot like our 2014 VW (non-plug in) hybrid. Braking in that took some getting used to. I'd think Toyota would have this figured out by now, I can't tell you how many rental Priuses I've driven and they don't have that problem.

 

[RcvrdOutback]

I can't hardly tell other than sometimes it feels like the brakes are fading, so you press harder, then all of a sudden, they grab. It has been an adjustment for me.

That’s a perfect way to describe it. I thought I was crazy for a while. Anytime I’m braking later from a higher speed, I experience this brake fade feeling. Not a huge fan.

I’d much rather the engine braking do the work as I prefer to coast in traffic.

 

[Altitude]

That’s a perfect way to describe it. I thought I was crazy for a while. Anytime I’m braking later from a higher speed, I experience this brake fade feeling. Not a huge fan.

I’d much rather the engine braking do the work as I prefer to coast in traffic.

I’m obsessive about engine braking on mountain grades. People around here warp their discs by riding their brakes. I-70 Eisenhower to Silverthorne drops 2400 feet in about 12 miles.

 

[Don]

I think the engine brake feeling is regen from automatic braking if enabled, at least if the vehicle determines it can slow down enough not using the mechanical brakes. So I think the hybrid battery is charged three ways:

1) Automatic braking when approaching traffic or (very) possibly light/stop signs
2) Light brake pedal push
3) Generator powered by the engine when hybrid battery charge is too low

#3 exists because the motor is always intended to be available to provide torque until the engine/turbo spools up. A prius isn't designed to do #3.

The vehicle isn't doing actual engine braking except in manual or descent control.

Adding a large inverter load should brake the vehicle on long mountain downhill grades. Watts produced from the inverter are watts not dispersed through the brake pads.

 

[Tripod1404]

I think the engine brake feeling is regen from automatic braking if enabled, at least if the vehicle determines it can slow down enough not using the mechanical brakes. So I think the hybrid battery is charged three ways:

1) Automatic braking when approaching traffic or (very) possibly light/stop signs
2) Light brake pedal push
3) Generator powered by the engine when hybrid battery charge is too low

#3 exists because the motor is always intended to be available to provide torque until the engine/turbo spools up. A prius isn't designed to do #3.

The vehicle isn't doing actual engine braking except in manual or descent control.

Adding a large inverter load should brake the vehicle on long mountain downhill grades. Watts produced from the inverter are watts not dispersed through the brake pads.

Prius can do #3, it can do it a lot better than LC as well.

LC can do actual engine breaking, it is even in the manual. Part of the engine breaking in this case is also coming from the electric motor (regen breaking) depending on how much power battery is willing to accept, and the rest is traditional compression breaking by the engine.

 

[EOD Guy]

My brother has Prius's and they do #3 and one of his has a bad Hybrid battery and runs on engine only and still gets 30-35 MPG.

 

[LCOceans]

That’s a perfect way to describe it. I thought I was crazy for a while. Anytime I’m braking later from a higher speed, I experience this brake fade feeling. Not a huge fan.

I’d much rather the engine braking do the work as I prefer to coast in traffic.

Perfect description. I do not understand any of this. Regenerative braking or whatever is going on. All I can say is sometimes it's hard to predict what they will do, which is a little uneasy. I had put it off to maybe driving in ECO. Maybe just need more time with the truck. But it sounds like this is normal.

 

[Don]

Prius can do #3, it can do it a lot better than LC as well.

LC can do actual engine breaking, it is even in the manual. Part of the engine breaking in this case is also coming from the electric motor (regen breaking) depending on how much power battery is willing to accept, and the rest is traditional compression breaking by the engine.

View attachment 11520

Are they just describing descent control (DAC)? Or will cruise control also brake?

 

[Tripod1404]

Are they just describing descent control (DAC)? Or will cruise control also brake?

Cruise control definitely uses engine breaking, based on my personal experience.

 

[HarvLC]

I wish electric motor gauge had an opposite direction to show how much regenerative breaking is being applied. They have this on their regular hybrids where the gauge is split between Charge/Power. It is very helpful if one wants to apply just enough pressure to slowdown or maintain speed downhill without maxing regenerative breaking.

I too wish there was some real-time indicator when you’re using the regenerative braking vs friction braking. Normally, I don’t like to ride traditional brakes but I have been braking earlier & more gradually in hopes of storing electricity. You eventually see that the electric battery’s charge has been increased but I don’t have any immediate feedback as to which form of braking that I’m using.

For those experiencing unsmooth braking action, have you turned off PDA? I did not like how that impaired braking, etc but haven’t really felt any issues once I turned it off.

 

[EOD Guy]

Are they just describing descent control (DAC)? Or will cruise control also brake?

No

 

[GCD]

That’s a perfect way to describe it. I thought I was crazy for a while. Anytime I’m braking later from a higher speed, I experience this brake fade feeling. Not a huge fan.

I’d much rather the engine braking do the work as I prefer to coast in traffic.

Yes, beware the nanny's, I've decided to keep them all on and learn to use them to my advantage. In particular the PDA can fight the throttle when approaching a stopped car, pedestrian, bike, etc. but if you recognize it's there it makes driving smoother hence better fuel economy.
There have been times I was ready to shut them all off but trying to roll with it.