Regeneration is limited please use the brake pedal.

[Peacsy]

1st Gen ZS EV which has 5 year service last week, they mentioned slight rusting on the brakes so turned kers down to 1 and tried to give them a little clean.

However since then and turning back up to 3 I've noticed when I start the car I get the "Regeneration is limited please use the brake pedal" message pop up, even though it feels like it's working once I set off?

Any ideas.

 

[GaryMG4]

My MG4 does that when the battery is at 100%.

 

[Peacsy]

The battery level is around 90% currently, so it's not as if the energy doesn't have anywhere to go.

 

[GaryMG4]

The battery level is around 90% currently, so it's not as if the energy doesn't have anywhere to go.

Our Niro gives the same warning at lower %ages than the MG, maybe its just part of the way the BMS is programmed, or just that at regen 3 it can put in a higher current that the BMS will allow.

 

[Peacsy]

Our Niro gives the same warning at lower %ages than the MG, maybe its just part of the way the BMS is programmed, or just that at regen 3 it can put in a higher current that the BMS will allow.

It's odd that this has started happening since the service, as I had never experienced it previously, even when the battery was fully charged. Although I have tried balancing the battery since then, so maybe that's something to do with it? (told at service battery health was 90% and they suggested that might help).

Do you know if there's any way to monitor regen when driving?

 

[GaryMG4]

It's odd that this has started happening since the service, as I had never experienced it previously, even when the battery was fully charged. Although I have tried balancing the battery since then, so maybe that's something to do with it? (told at service battery health was 90% and they suggested that might help).

Do you know if there's any way to monitor regen when driving?

On the MG4 it shows %age braking effort and the consumption screen 'should' show how much has been returned. Maybe a ZS owner will be able to help.

 

[elkay62]

On the MG4 it shows %age braking effort and the consumption screen 'should' show how much has been returned. Maybe a ZS owner will be able to help.

I think on this screen you will see moving arrows when you are driving, indicating the flow of electricity. Obviously I can't take a pic when I'm driving :-D

If you accelerate you will see the charge going one way, and a positive figure in the power% on the right. If you are in regen 3 and lift off the accelerator, the arrows will reverse direction and you will see a negative value in the power%.
As mentioned already, if the battery is close to 100%, there will be no regeneration. Not sure how much it needs to drop to start regerating, but I believe it does regerate at 90% on my car.

 

[hmadsen]

The battery level is around 90% currently, so it's not as if the energy doesn't have anywhere to go.

The capacity to store the energy is not the only factor limiting this function.

If the battery is cold, it will not be able to accept as much power as when it is at running temperature.

So if your battery is pretty cold and the charge is at 90%, it might not be able to accept the current the regen can put into it.

Imagine this....When regen braking you might feed a LOT of amps into the battery in a short time, if those AMPS exceed what the battery is able to take, they give you this warning so that you are aware, it won't regen brake at full power.

On my Tesla there is an icon that means the same as what the ZS EV put on the screen, I have seen this icon on at only 55% SoC on a cold cold morning (-11 Celsius).

Moderator: SoT -> SoC; I hope that's what you meant.

 

[mikgle]

1st Gen ZS EV which has 5 year service last week, they mentioned slight rusting on the brakes so turned kers down to 1 and tried to give them a little clean.

However since then and turning back up to 3 I've noticed when I start the car I get the "Regeneration is limited please use the brake pedal" message pop up, even though it feels like it's working once I set off?

Any ideas.

Regen will be limited at 90% SoC i believe.. so its a fair notification.

 

[decrep]

Regen will be limited at 90% SoC i believe.. so its a fair notification.

At 90% I don't have any regen limit, it's perfectly happy in OPD.
0 regen at 100%, but comes back in slowly at high 90s, slowly increases until about 93% when full regen becomes available.
I'm not sure if there's a temperature dependency here, the battery can charge better at higher temps, but this is not about charge current, it's about state of charge.

 

[hmadsen]

At 90% I don't have any regen limit, it's perfectly happy in OPD.
0 regen at 100%, but comes back in slowly at high 90s, slowly increases until about 93% when full regen becomes available.
I'm not sure if there's a temperature dependency here, the battery can charge better at higher temps, but this is not about charge current, it's about state of charge.

Yes, but when the car does regen braking it actually charges with quite a lot of amps, so if the battery is cold it might now want to accept that many amps.

The charge curve indicates that at 90% SoT, under ideal conditions you can only put 20KWh into the battery, so if it is really cold that might be less and if the car then tries to put 15KWh into the battery but it is cold so can only accept 10 KWh, it will warn you.

It's pretty easy, the car calculates the max current the battery can accept, based off of SoT and temperature and if this figure is lower than then maximum the regen braking is able to put in, the car will warn you.

As stated earlier, on a cold day with minus 10c i have seen the "regenerative braking limited, telltale" on my Tesla on, even at a SoT of around 50-60% SoT.

 

[decrep]

Yes, but when the car does regen braking it actually charges with quite a lot of amps, so if the battery is cold it might now want to accept that many amps.

The charge curve indicates that at 90% SoT, under ideal conditions you can only put 20KWh into the battery, so if it is really cold that might be less and if the car then tries to put 15KWh into the battery but it is cold so can only accept 10 KWh, it will warn you.

It's pretty easy, the car calculates the max current the battery can accept, based off of SoT and temperature and if this figure is lower than then maximum the regen braking is able to put in, the car will warn you.

As stated earlier, on a cold day with minus 10c i have seen the "regenerative braking limited, telltale" on my Tesla on, even at a SoT of around 50-60% SoT.

Yes, well we don't experience those low temps here, outside temps can get down to 5°C, but inside the garage it will be warmer.
I had a feeling that Battery temperature could limit charge current, so as you say that will also affect the level of regen available.
However it shouldn't have a lot of effect on the SoC that some regen is available at.

I think you are wrong about kWh, I don't think the battery looses its capacity with low temps. At 95% SoC it can still accept 5%, but at a reduced rate when it's cold.

 

[hmadsen]

Yes, well we don't experience those low temps here, outside temps can get down to 5°C, but inside the garage it will be warmer.
I had a feeling that Battery temperature could limit charge current, so as you say that will also affect the level of regen available.
However it shouldn't have a lot of effect on the SoC that some regen is available at.

I think you are wrong about kWh, I don't think the battery looses its capacity with low temps. At 95% SoC it can still accept 5%, but at a reduced rate when it's cold.

At lower temperature the battery does not lose actual energy, but the car might limit the cars ability to extract all of that energy.

I have a friend that is better at explaining it i think (The 55KWh was its response to a previous question, not something i just made up myself)

---------------

So what happens if i put 60KW into an EV battery at 25 celcius and leave it outside overnight and the temperature drops to 0 celcius.Would i then have 60KWh available for the drive or only 55KWh and if 55KWh, where did the last 5KWh go ?

ChatGPT said:​

---

Scenario:​

• You charge the battery to 60 kWh at 25 °C.
• You leave it outside, it cools down to 0 °C overnight.
• You wonder: how much energy is now available?

---

1.​

The battery still contains 60 kWh of chemical energy. Energy didn’t magically disappear. So in theory, the total energy is unchanged.

---

2.​

Here’s the catch: at low temperatures:

• Internal resistance rises → more voltage drops under load.
• Battery management system (BMS) may limit usable SOC for safety.
• Lithium ions move more slowly → maximum discharge current is reduced.

So while the battery has 60 kWh stored chemically, you might not be able to safely extract the full 60 kWh at 0 °C. The BMS may only let you access, say, 55 kWh, or the effective range may feel shorter because voltage drops sooner under load.

Think of it like this: the energy isn’t gone—it’s temporarily “inaccessible” until the battery warms up.

---

3.​

• It’s still in the battery, just trapped by physics and safety limits:
  
  1. Voltage sag at low temperatures makes the BMS cut off earlier to avoid damaging the cells.
  2. Electrochemical sluggishness: lithium ions move slower, so not all energy can be extracted efficiently.
  3. Internal heating losses: some energy is lost as heat if you try to draw high current in the cold.

So it’s not truly “lost,” just temporarily unusable. Warm it back up (by driving or preheating), and you can get it back.

 

[decrep]

But we're not talking about extracting energy, we're talking about putting energy back in.

Yes the rate it goes back in will be reduced, but it can still go in.

 

[hmadsen]

But we're not talking about extracting energy, we're talking about putting energy back in.

Yes the rate it goes back in will be reduced, but it can still go in.

Offcourse, but as you can see, the chemistry is not able to source or accept nearly as high amounts of energy when cold, so even at lower than 90% SoC, the battery will struggle to accept, maybe even only 10-20KWh from the motor at full regen braking and that's why it will warn you, that it might not be able to do full regen braking, because the battery is simply in a state, where it can not accept a full regen load.

 

[decrep]

Isn't that what I just said?

 

[hmadsen]

Isn't that what I just said?

Yes, i was just unsure if you understood that this is exactly what is generating the message.

Seems you did then.