Why has my regenerative braking stopped working?

Most often because the battery cannot accept the charge. Regeneration is charging, so a battery already at or near full has nowhere to put the energy, and a very cold battery cannot take it quickly. Both are normal and both resolve — the first as you use some charge, the second as the pack warms. If the battery is warm and around half full and regeneration is still missing, there is a fault in the brake control or drive system and it needs a diagnostic.

Is it normal to lose regen when the battery is full?

Completely normal, and every electric and hybrid car does it. Charging to a hundred per cent and setting off down a hill is the classic case: there is no room in the battery for the energy the motor would generate, so the car limits regeneration and you get much less deceleration when you lift off than you are used to. Manufacturers usually recommend charging to around eighty per cent for daily use anyway, which mostly avoids the problem.

Is it safe to drive without regenerative braking?

Yes. The friction brakes are a separate hydraulic system and are not affected, so the car stops as well as it always did. What changes is how it behaves when you lift off the accelerator: instead of slowing firmly, it coasts. The risk is entirely one of expectation, so leave extra room and brake earlier until you have adjusted, and be particularly careful on long descents where one-pedal driving would normally have held your speed.

Do electric cars fail their MOT on brakes?

More often than owners expect, and usually for corrosion rather than wear. Because regenerative braking does most of the slowing, the discs and pads on an electric or hybrid car can go tens of thousands of miles barely being used, and unused discs rust, pit and occasionally seize. On the MOT roller test that shows up as uneven braking effort between the two sides, which is a failure, or as a disc worn or corroded below its minimum thickness. Braking firmly on the friction brakes now and again, on a quiet road, keeps the discs clean and is the cheapest preventative there is.

Dashboard warning light

Regenerative braking warning light

Last updated 27 July 2026

Quick answer

Regenerative braking has been reduced or switched off, so the motor is no longer slowing the car and putting energy back into the battery. The friction brakes take over and still work normally, but the car coasts where you expect it to slow.

What to do: Get it checked within days
Can you drive?: Yes

Why it is amber

A system has reported a malfunction, or something needs attention. The car is usually still driveable, but the fault will not clear itself and several amber lamps are an automatic MOT failure.

What turns it on

Regeneration is charging, so it can only happen when the battery is able to accept charge. A full pack has nowhere to put the energy and a very cold pack cannot take it quickly, so the car limits or removes regeneration in both cases. It also does so when the brake control system, the inverter or the battery management system reports a fault it cannot work around.

What to do about it

Leave more room and brake earlier for the first few miles. The change in how the car slows when you lift off is significant on a car with strong one-pedal driving, and it takes a junction or two to recalibrate.
Check the state of charge. If you have just charged to a hundred per cent and set off downhill, reduced regeneration is completely normal and will return as soon as the battery has room again.
Check the temperature. A pack sitting below freezing will not accept much charge until it warms, so the first few miles of a frosty morning often have little or no regeneration.
If the warning persists with the battery warm and around half charged, get the codes read. At that point it is a fault in the brake control or drive system rather than physics.
Use the friction brakes deliberately now and then whatever the car is doing. Cars that regenerate almost all the time leave their discs unused, and unused discs corrode.

Can you keep driving?

Yes

Yes. The friction brakes are entirely independent of regeneration and are unaffected, so the car still stops properly — it simply does not slow itself when you lift off. The genuine hazard is the surprise, particularly on a long descent, where a driver used to one-pedal braking can find themselves carrying far more speed than expected. Drive it like a conventional automatic until it comes back.

What causes it

A fully or nearly fully charged battery with no capacity to accept the energy, which is normal and not a fault
A very cold battery pack, which limits charge acceptance until it warms up
A very hot battery pack, for the same reason at the other extreme
Battery degradation on an older car, narrowing the window in which full regeneration is available
A fault in the brake-by-wire or brake blending system, which is the case that actually needs a garage
An inverter or motor fault the car has derated around
A stability control or ABS fault, since regeneration is coordinated with those systems and gets disabled when they are unavailable

Does it fail an MOT?

Not on its own — but what causes it often does.

There is no defect for the regeneration lamp, and the roller brake test measures only what the friction brakes do. The indirect link is the important one and it runs the other way from what owners expect: electric and hybrid cars use their discs so lightly that the discs corrode, pit and sometimes seize, and the resulting uneven braking effort shows up on the rollers as an imbalance failure, or as discs recorded below their minimum thickness once corrosion has eaten into them. It is one of the most common MOT failures on otherwise immaculate low-mileage EVs.

Common questions

Why has my regenerative braking stopped working?: Most often because the battery cannot accept the charge. Regeneration is charging, so a battery already at or near full has nowhere to put the energy, and a very cold battery cannot take it quickly. Both are normal and both resolve — the first as you use some charge, the second as the pack warms. If the battery is warm and around half full and regeneration is still missing, there is a fault in the brake control or drive system and it needs a diagnostic.
Is it normal to lose regen when the battery is full?: Completely normal, and every electric and hybrid car does it. Charging to a hundred per cent and setting off down a hill is the classic case: there is no room in the battery for the energy the motor would generate, so the car limits regeneration and you get much less deceleration when you lift off than you are used to. Manufacturers usually recommend charging to around eighty per cent for daily use anyway, which mostly avoids the problem.
Is it safe to drive without regenerative braking?: Yes. The friction brakes are a separate hydraulic system and are not affected, so the car stops as well as it always did. What changes is how it behaves when you lift off the accelerator: instead of slowing firmly, it coasts. The risk is entirely one of expectation, so leave extra room and brake earlier until you have adjusted, and be particularly careful on long descents where one-pedal driving would normally have held your speed.
Do electric cars fail their MOT on brakes?: More often than owners expect, and usually for corrosion rather than wear. Because regenerative braking does most of the slowing, the discs and pads on an electric or hybrid car can go tens of thousands of miles barely being used, and unused discs rust, pit and occasionally seize. On the MOT roller test that shows up as uneven braking effort between the two sides, which is a failure, or as a disc worn or corroded below its minimum thickness. Braking firmly on the friction brakes now and again, on a quiet road, keeps the discs clean and is the cheapest preventative there is.

This is general guidance, not a diagnosis. Manufacturers draw the same system differently and reuse symbols for more than one function, so check the handbook for your own car before acting on anything here.

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