Reduced power mode at 23%

[Verdigris]

I'm resurrecting this thread as it's what came up in my search before I started a new post.

Just a heads up as it caught me out and I was not impressed......

Car had 30% remaining yesterday but I did use 10% to charge my solar battery bank overnight.

So after pre heating the car this morning,
(Minus 2) I had 19% battery.
I forget the exact miles, but it was triple what I needed to reach the charger.

Half the journey is 70mph on the A40.

Not today it wasn't!!!

Nothing worse than asking for power and not getting it!!!
66, 64, 61, 59, fudge!
I thought it might actually bloody stop.

This was now at 6% but I had twice the mileage I needed to get charged.

All I will say is, that I will be very much more wary next time and take the back road to Carmarthen.

I do KNOW why it did it, but am still not amused. (not amused so uses lol emoji)

There must be something about Carmarthen. I had to go to Port Talbot, from Mid Wales, a couple of months ago and I intended to return via Carmarthen to pick up some stuff from B&Q. Anyway, time ran away a bit, the weather was awful, so I decided to abandon the DIY bit and go straight home, as the Octopus Agile price was going negative that afternoon. Turned out to be a good decision as I squeaked home on 2% battery. I can't say I really noticed any drop in performance, although I was using a featherweight right foot anyway. The most disconcerting bit was that the GOM goes blank quite early, so you have to do the sums in your head. Luckily my mental arithmetic is reasonably good.

 

[Bricktop X PWR]

It hasn't struggled before, even at 4%,
So it must be down to the cold weather I'm sure.

 

[MickeySw]

Generally speaking the BMS computer in an EV monitors two values for each cell, voltage and capacity. All the cells are connected in series which means that the weakest cell determines the performance of the whole battery.

The GOM is using remaining capacity, previous and current power usage and temperature to determine (educated guess) the remaining range.

The BMS prevents any cell voltage to drop off the cliff and venture into the danger zone, it first limits power and then eventually turns off the HV battery to prevent permanent damage. See graph in post #50.

Cell voltage drops the more power you use and battery capacity reduces in cold weather.

Therefore driving heavy footed in cold weather on low charge is best to be avoided…

 

[Verdigris]

I've noticed the GOM gets more conservative before it finally gives up calculating the range.

 

[Bricktop X PWR]

Generally speaking the BMS computer in an EV monitors two values for each cell, voltage and capacity. All the cells are connected in series which means that the weakest cell determines the performance of the whole battery.

The GOM is using remaining capacity, previous and current power usage and temperature to determine (educated guess) the remaining range.

The BMS prevents any cell voltage to drop off the cliff and venture into the danger zone, it first limits power and then eventually turns off the HV battery to prevent permanent damage. See graph in post #50.

Cell voltage drops the more power you use and battery capacity reduces in cold weather.

Therefore driving heavy footed in cold weather on low charge is best to be avoided…

If driving at the speed limit is "heavy footed" then guilty as charged, but I get your point.

 

[Stuart Wright]

If driving at the speed limit is "heavy footed" then guilty as charged, but I get your point.

In terms of efficiency, there is a big difference between 60 and 70. I used to tailgate lorries in my 2017 Ioniq so I noticed way better m/kWh at 60 than tailgating coaches at nearer 70.
So if you’re kind of low on charge and it’s cold, play it safe.
Also don’t treat EVs like ICE cars when it comes to running out of energy. 35 years of driving petrol and diesel, I used to rock up to the forecourts on fumes. It was ok to let the gauge go to zero.
You can’t think this way with EVs. Some may keep going a bit on zero maybe if it’s warm and depending on the model.
But here is my experience of running out in an EV.

 

[MickeySw]

But here is my experience of running out in an EV.

I keep an “universal EV charger” in my boot for just such an occasion, it’s called a tow-rope.

I know the manual states bla bla bla… but if it’s possible to push the car then pulling will work also, just a lot less elbow grease required..

You could even go a step further and put it into drive and Kers1 for a battery top up..

 

[dragon2611]

My MG5 LR told me aggressive driving is not recommended at 7% SOC when I tried to pull out of a side road onto a hill but it didn't limit power.

 

[jpvdheijn]

yesterday in the cold here in the Netherlands I received the message reduced power on the highway at around 9%. I think this has to do with the heat in the batteries and the temperature outside. On journeys in spring summer or autumn this never happened at this state of charge.