Regeneration brake light

[Les burrows]

Not that it counts for much, but I asked the MG dealer about this very point and he said that in KERS3, the brake lights will come on (which they should IMHO, given the amount of retardation you get), but it seems this may not be the case. I will certainly be checking this when I pick mine up...

Hi and hello arfurM I see you new here so welcome you will find lots of stuff to read about here on this forum and others there’s lots good information and some not so good so just take your time it’s worth the read be aware sometimes the ZS can pop up in the MG5 forum and vice-versa and as you are getting the 5 make sure the comments your reading are about the 5 as there are quite a few differences in the cars in some areas. As for this thread about the brake lights it’s been on going since May1st when Jeff asked do the brake lights come on under heavy Regenerative braking I myself only saw this last Thursday and there didn’t appear to be an total answer really to his question so I decided To do a little test with my MG5 and I can tell you that the brake lights don’t come on unless you touch the brake pedal which is not a problem the car slows very well under regen braking only but not quite to a total stop that does need the brake pedal touched very lightly as you coming to a halt In any mode or regen setting the way I drive is, if there is no one close behind me I come off the accelerator and use the cars Regen until the last few yards and then apply the foot brake in the last yards but if someone is close behind me I light touch my brakes so the brake lights will come on so they know I’m slowing and let the regen slow me down until I need to apply the footbrake to come to a complete stop again, dead easy no problems at all I found the only time the brake lights are on with out you touching the brake pedal is when you stop and you have the auto hold switched on then the lights stay on until you move off again anyhow that’s what I found with my car so check yours when you get it like you said you would in your post and let us know your findings enjoy it’s a very nice car yes there a bit of a learning curve you will probably need to do but there’s loads of help here on this forum with anything really don’t hesitate to ask questions plus if you are unaware there are numerous podcasts on the YouTube channel MGEVs
Les

 

[ArfurM]

Hi Les, and cheers... Yeah, what you say sounds resonable, it was just I was a bit surprised how strong the deceleration was on KERS3, so was concerned it could catch out dopey drivers behind. Still, not that different riding a big V-twin when my mates were on inline 4's, and I rolled of the throttle.. Same effect.....

 

[Adee]

Not that it counts for much, but I asked the MG dealer about this very point and he said that in KERS3, the brake lights will come on (which they should IMHO, given the amount of retardation you get), but it seems this may not be the case. I will certainly be checking this when I pick mine up...

That is a useful snippet, Arfur. You'll love the car, BTW. Several people including myself have tested this and it certainly does not come on (unless they have very recently changed the design). Personally I think it is worth following up but I'm not sure how to go about it! You can't really expect a salesman to get too interested in the problem can you?

 

[ArfurM]

I'll raise it when I pick up the car, the dealler seems v.helpful and engaged, so perhaps it can be passed up to "the mother-ship". On balance, I do feel that the amount of deceleration available, should you suddenly lift off the gas (Amps? Electrons?) could catch out the inattentive behind you... Anywho, I guess these days it's a software fix, not a fundemental re-wiring job....

 

[Les burrows]

Hi Les, and cheers... Yeah, what you say sounds resonable, it was just I was a bit surprised how strong the deceleration was on KERS3, so was concerned it could catch out dopey drivers behind. Still, not that different riding a big V-twin when my mates were on inline 4's, and I rolled of the throttle.. Same effect.....

Hi les again another thing about Kers it can have differences with the state of charge in the battery I.e when the battery is full or at the top end of charge there can be very little or no regen as when the battery full or almost there’s no where for the regenerated Electrons to go so that’s another characteristic to be aware of and when the battery gets a little on the low side the regen can feel stronger there is lots of what’s right and what’s wrong in this and I can only speak for myself I do my best to read the road ahead and brake accordingly I tend to drive in E mode with various kers levels I:e motorway I use E1 around town 1or2 awitching to 3 as and when I can see I will need to stop it fact it’s very strange I seem to have my right hand spending as much time by the kers switch as it does on the steering wheel when not on a motorway or other fast road everyone does things differently and as with other things in EV ownership somethings can be a little new but you will very soon find your best set up for yourself
The think the last time I riding something with wheels on it was a Triumph 21 350cc twin lol
Les

 

[Les burrows]

I'll raise it when I pick up the car, the dealler seems v.helpful and engaged, so perhaps it can be passed up to "the mother-ship". On balance, I do feel that the amount of deceleration available, should you suddenly lift off the gas (Amps? Electrons?) could catch out the inattentive behind you... Anywho, I guess these days it's a software fix, not a fundemental re-wiring job....

You might be correct but I very much doubt it
So here another reason not to rely on kers I fully charged my car last night and did the battery Equalisation step as well and this morning setting off with a 100% battery and as I said in my other post #85 very very little regen braking in fact only kers 1&2 would work as for kers 3 when you try to switch that on the car won’t let you and it would not go into kers 3 until I got down to about 97% battery and then at that level there is very little regen braking at all by the time it got to around 95% then you could feel something starting to happen but not very heavy as I said before it appears the lower the charge in the battery the stronger the regen picture below at 100%
So no brake lights and no regen braking when fully charge the plot Thickens
Les
16 :35 just dine an edit on spelling mistakes was on my phone this morning please excuse me hope this post now makes more sense.
Les

 

[Adee]

You might be correct but I very much doubt it
So here another reason not to rely on kers I fully charged my car last night and did the battery Equalisation step as well and this morning setting off with a 100% battery and as I said in my other post #85 very very little regen braking in fact only kers 1&2 would work as for kers 3 when you try to switch that on the car won’t let you and it would not go into kers 3 until I got down to about 97% battery and then at that level there is very little regen braking at all by the time it got to around 95% then you could feel something starting to happen but not very heavy as I said before it appears the lower the charge in the battery the stronger the regen picture below at 100%
So no brake lights and no regen braking when fully charge the plot Thickens
Les
16 :35 just dine an edit on spelling mistakes was on my phone this morning please excuse me hope this post now makes more sense.
Les
View attachment 3607

The regenerative braking doesn't work until the charge is down to about 95%, Les. It's for the simple reason that there is "space" in the battery to take the charge. As soon as it drops below around 95% everything is back to "normal". By the way I did some accelerometer measurements using various KERS settings and found that the extent of regenerative braking also varies depending on battery load (e.g.aircon etc). IIRC, the more load the less the available regen.

 

[Adee]

I'll raise it when I pick up the car, the dealler seems v.helpful and engaged, so perhaps it can be passed up to "the mother-ship". On balance, I do feel that the amount of deceleration available, should you suddenly lift off the gas (Amps? Electrons?) could catch out the inattentive behind you... Anywho, I guess these days it's a software fix, not a fundemental re-wiring job....

Thanks Arfur.
I, for one, would appreciate that as (like you) I think the brake lights should come on given the amount of braking power available from KERS3. The brake lights do illuminate in the MG SUV model so why did they delete it from the MG5? Maybe this is what the dealer is getting confused with when he told you he thought that the brake lights came on with KERS? Anyway, I previously published some accelerometer measurements I made in one of these posts so the dealer could be informed if necessary of the actual figures. Good luck.