Jomarkh
Distinguished Member
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- Apr 5, 2021
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- Driving
- MG5 Excite
Bear in mind most ICE drivers won't know what KERS is.I put this on the back of the car this morning
Hi n8sail this test I did was just a temporary wiring job to to prove if the brakes worked or not under regen and no they do not the wiring and the beeper have now been removed I’m sorry if I may have confused you in anyway and yes I know some vehicles will give you an alert if you have a bulb out my skoda Superb did that and it was very useful to haveThanks for the great testing, Les!
Indeed concerning. Driving where I live is dangerous enough as it is (Thailand is consistently top 3 in the world for deaths on motorways!) Already had a few people act aggressively towards me after a 'quick' slow down in KERS 3. I have started just touching the brake pedal in situations where it looks like following drivers are too close now, but then of course you cannot modulate your KERS stopping power then other than flicking the level down.
Any dashboard lights/alarms appear with the extra wiring and beeper wired in circuit? I believe some modern cars with CAN bus will throw errors or codes when a bulb is out. Usually this is detected by change in resistance of the circuit... adding a few meters of cable and a different load to the circuit might trip it off, or perhaps the MG5 just doesn't use this feature in CAN bus protocol.
Good test Les. On the ZS I’m told that the brake lights work in regen3 and are based on a decelerometer - greater than a certain level of deceleration and they come on - I’ve not tested this though. It is definitely something to be aware of when driving these cars as many road users seem to completely rely on brake lights on the car in front to tell them when to slow down.Hi n8sail this test I did was just a temporary wiring job to to prove if the brakes worked or not under regen and no they do not the wiring and the beeper have now been removed I’m sorry if I may have confused you in anyway and yes I know some vehicles will give you an alert if you have a bulb out my skoda Superb did that and it was very useful to have
Just be carful when slowing with high regen as traffic behind you I no idea and you can slow down quite quickly in kers 3
Les
Hi Cocijo thanks for your reply not sure if you have a 5 or ZS but some on this thread appeared to be under the same impression that the lights came on at certain levels of deceleration on the 5 which is why I did this testing to find out the true story it needs someone to do the same thing with the ZS it’s not difficult and takes very little time I think using a buzzer/bleeper is the best way as you can’t miss it while looking away ie watching traffic for example as you might do with a little bulb in daylight and sunshine, the one I used is only small but at 100dbs you certainly hear it and of course it only sounds when the brake light is onGood test Les. On the ZS I’m told that the brake lights work in regen3 and are based on a decelerometer - greater than a certain level of deceleration and they come on - I’ve not tested this though. It is definitely something to be aware of when driving these cars as many road users seem to completely rely on brake lights on the car in front to tell them when to slow down.
Hi lan don’t see what that would do or prove all I know is the MG5 brake lights do not come on at any speed or in any setting and how you can slow down faster than KERS 3 in any mode I don’t know unless of course you run into something in front of you or apply the brakes then the lights will come onHi Les, how about repeating the test with a decelerometer in the car? If you have a phone with one built in... In my car I didn't think I got above the 0.3 legal limit.
Ian
Interesting test. I think perhaps that if you don't use the footbrake pedal then even in Kers3 at 70 the deceleration will not be sufficient to trigger a light.no matter which KERS setting I used in any of the modes the brake lights do not come on unless you use the foot brake in KERs 3 from almost 70 I took my foot off the pedal to get as much regen as possible still nothing from the bleeper
Well done for doing the test, Les. It's useful information.Hi lan don’t see what that would do or prove all I know is the MG5 brake lights do not come on at any speed or in any setting and how you can slow down faster than KERS 3 in any mode I don’t know unless of course you run into something in front of you
Les
by putting your foot on the brake pedal in kers3 it continues to increase the regen until it limits and then applies the brake. That will be a faster deceleration than simply taking your foot off the pedal.how you can slow down faster than KERS 3 in any mode
Hi. I already did this and reported it earlier in the thread. I'm of the opinion that the brake lights under a certain deceleration should come on. They've done it on the SUV, why not do it on the MG5 - I can't see the logic? This is a safety issue that they should address ASAP before too many road rage incidents accumulate. I didn't get much support in my views, however.Hi Les, how about repeating the test with a decelerometer in the car? If you have a phone with one built in... In my car I didn't think I got above the 0.3 legal limit.
Ian
as said above - because in the 5 most of the kers effect comes from using the decelerate pedal, the amount that comes from taking foot off the accelerator is simply like engine braking in an ICE and not enough to merit a brake light.They've done it on the SUV, why not do it on the MG5
Hi Roger all I can tell you is I did what I could to try and find if the brake lights work under regen conditions only.Interesting test. I think perhaps that if you don't use the footbrake pedal then even in Kers3 at 70 the deceleration will not be sufficient to trigger a light.
If you are in Kers3 and you do put your foot on the brake lightly then you can see that the power meter goes deeper into the blue as the deceleration is handled by the Kers. In this case I would expect the brake light to come on.
(it may be that it is nothing more than a conventional switch on the pedal).
If in kers3 you press the pedal a bit harder you can see that the brakes are starting to work as the power meter doesn't move so far into the blue. This should certainly put the brake lights on.
This is just a working hypothesis -
a) with no pedal pressed at any speed on the flat the deceleration is not sufficient to require a light. This is demonstrated by @Les burrows test.
b) with no pedal pressed going up a hill it (say greater than 8%) it might be that kers and gravity (conversion of kinetic to potential energy) combined could be enough to trigger a brake light.
? not tested by Les? Need to find an empty motorway with a long steep climb and re-test.
c) with the brake pedal pressed just enough to make all of the deceleration come from Kers the brake light should come on (switch on pedal?).
Since the brake light comes on if you are stationary and touch the brake pedal (try it reversing up to something so you can see the reflection) my guess is that there is a conventional switch on the pedal - which will be triggered by kers braking if you are touching the pedal - and the only 'clever' bit is the hill start (auto hold) mode where Les's test shows that the brake light comes on when you move from P to D and take your foot off the pedal so that the car stays stationary against the hill instead of gliding off.