Regenerative Braking

[Trewithy]

I should be picking up my Corolla on Monday and it will be my first hybrid car so I have some questions regarding regenerative braking.  First of all I live in a hilly area and my driving style is quite relaxed.  If I am approaching a red light I like to throttle off early and let the car lose speed naturally, then gently brake at the end.  In a hybrid, when you lift off the gas is the car charging the Battery as you coast along and is the charging rate increased going downhill in the B position?  Also on gentle braking is it just the regenerative effect that is slowing the car down and not the friction brakes.

I am coming from a normal automatic so any hybrid driving tips would be appreciated.  I would like to drive efficiently but I am not hung up on achieving the highest MPG possible, I will be using the heated seats, air con etc when required.  In my current car the climate control is always on, usually on the Auto position.

[Gray86]

When you lift off accelerator you get a bit of regenerative braking, but you need to hold the brake to get Max regen (you can see the bar on the display fill up). B mode (in a 1.8 - N/A on 2.0) just uses the combustion engine to generate drag - ideal if your hybrid Battery is full. 

[AndrueC]

Lifting off ('engine braking') recharges the Battery a bit. Using the brakes recharges the Battery a lot.

However you should keep in mind that the electrical recovery system only recovers some of the energy you are losing and you incur further losses while discharging the Battery. It's not a perfect system. It is better to minimise energy loss in the first place.

As with any vehicle the most efficient way to drive is to minimise your use of the brakes.

In practice most of the battery charge comes from the engine running the motors as generators. It will try and do this in the most efficient way - typically by increasing the load on the engine to make it operate at a more efficient RPM (the engine burns more fuel but gets more energy out of the fuel it burns). You will also save the most fuel by using the battery only at low speed or light load - allowing the ICE to switch off. Using your battery to supplement ICE power is not best use of it and (take it from me as the owner of a lowly 1.8 Corolla) is not necessary.

Learn how to read the ECO gauge. Keep the green bar out of the 'PWR' zone and lift off early. Avoid using your brakes.

 

[TonyHSD]

Hi, 

You can just drive as you do your normal auto, when you go downhill and let the car roll the regen will work but slightly, to increase the load you just need to press the brake pedal as required, harder you step on more energy you will get back to the Battery, no need to use B mode at all. In general the hybrids use regen to slow down the car and use the disc brakes at the end of the braking process, with the time you are driving you will get to know your car and even can sense when the car slows down with the e motors and when with the brakes. The idea for the free roll as Andrue mentioned,  less use of the brakes works really well too. I also live at a bottom of a long hill and my hybrid  battery is always full. , just control the regenerative braking with the brake pedal, your brakes may not engage at all unless harder braking is required or after you had slowed down to almost a complete stop. 
 

[Jiff]

As Gray86 mentioned using B downhill the engine revs went up. It worried me the first time it happened as the  eco display showed no power being generated. It was the car loosing all the spare energy as the Battery was full. 

I can't say I've figured out all the permutations of engine / wheel / Battery usage, but it works well. 

Enjoy

[mjjferreira]

On 5/15/2021 at 10:44 PM, TonyHSD said:

Hi, 

You can just drive as you do your normal auto, when you go downhill and let the car roll the regen will work but slightly, to increase the load you just need to press the brake pedal as required, harder you step on more energy you will get back to the battery, no need to use B mode at all. In general the hybrids use regen to slow down the car and use the disc brakes at the end of the braking process, with the time you are driving you will get to know your car and even can sense when the car slows down with the e motors and when with the brakes. The idea for the free roll as Andrue mentioned,  less use of the brakes works really well too. I also live at a bottom of a long hill and my hybrid  battery is always full. , just control the regenerative braking with the brake pedal, your brakes may not engage at all unless harder braking is required or after you had slowed down to almost a complete stop. 
 

I can't tell the difference when its using regenerarive braking or the disc brakes at all.

Toyota has made regenerative braking top of the art! Really amazing.