Covered to some extent in the manual.

All braking is bad. Regen braking is less bad.

The power meter on the dash is your guide to braking. Keep the needle above the bottom peg and its all regen braking above 9MPH.

 

From the Toyota 2018 RAV4 HV Owner's Manual (OM42B81U), p. 319:

When braking
Make sure to operate the brakes gently and in a timely manner. A greater amount of electrical energy can be regenerated when slowing down

Otherwise, from p. 77:

■Regenerative braking
In the following situations, kinetic energy is converted to electric energy and deceleration force can be obtained in conjunction with the recharging of the hybrid battery (traction battery).
●The accelerator pedal is released while driving with the shift lever in D or S.
●The brake pedal is depressed while driving with the shift lever in D or S.

p. 76:

When braking (regenerative braking)
The wheels operate the electric motor (traction motor) as a power generator, and the hybrid battery (traction battery) is charged.

p.78:

Sounds may be heard due to regenerative braking when the brake pedal is depressed or as the accelerator pedal is released

p. 93 (the left meter in the dash console):

Hybrid System Indicator
Displays hybrid system power output or regeneration level (→P. 95)

p. 95:

1 Charge area (referring to the quadrant area on that same meter defined by "chg")
Shows that energy is being recovered via the regenerative brake.

4 Power area (referring to the quadrant area on that same meter defined by "pwr")
Shows that an Eco-friendly driving range is being exceeded (during full power driving etc.)

●By keeping the indicator needle within Eco area, more Eco-friendly driving can be achieved.

●Charge area indicates regeneration* status. Regenerated energy will be used to charge the hybrid battery (traction battery).

*: When used in this manual, “regeneration” refers to the conversion of energy created by the movement of the vehicle into electrical energy

p. 104:

■ Trip information
4 Regenerated energy in the past 15 minutes

p. 319:

Highway driving
Control and maintain the vehicle at a constant speed. Before stopping at a toll booth or similar, allow plenty of time to release the accelerator and gently apply the brakes. A greater amount of electrical energy can be regenerated when slowing down.

p. 551:

(Yellow)
Warning light and warning buzzer list
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system
→ Have the vehicle inspected by your Toyota dealer
immediately.

p.569:

"Breaking Power Low
Visit Your Dealer"
Indicates a malfunction in:
• The regenerative brake system; or
• The electronically controlled brake system
A buzzer also sounds.
→ Immediately stop the vehicle in a safe place
and contact your Toyota dealer.

 

So if your needle is all the way at the bottom, does that engage the brake pads?

 

Correct. There is no use of the friction brakes unless pedal pressure exceeds that mark, at which point the computer blends in the friction brakes. Its a "fly-by-wire" braking system. Friction brakes are used all the time below 10mph.

 

There is zero friction braking until max regen is reached. Obviously there are caveats like how hard you stomp on the pedal, speed, etc. The Rav is also unique in that it has 4-wheel regen.

 

Why are there two different posts from RD (5&6), why are they different, and why are they both edited by Dr. Dyno?

 

To avoid any confusion I deleted all mentions of regen braking on my Accord since it only applies indirectly to the RAV4 Hybrid. That kinda left a hole between what is now posts 5 & 6 but they still read properly IMO. 6 just adds more useful info to 5.