Driving MG4 to Zero%

[pjmmk]

When mine reached 9% SoC , the range changed to three dashes. I was only a mile or so from home so I didn't worry - but it's not really a very useful indicator!

 

[Rolfe]

When did you last do a long charge?

 

[siteguru]

When mine was down to 1% I'm fairly sure it still showed a range ... maybe 2 miles.

 

[Corindikev]

Never been below 5% but the car has never reduced power or made any comment other that the standard message at 20% & 10%. The 2.3% buffer from the so called 61.7% usable to dead empty probably gives a bit of crawl distance. I haven't been game to try it though.

 

[pjmmk]

When did you last do a long charge?

Me? That very day....
I cleared the timer and limit and plugged it in. Just left it there till it stopped taking power. I don't really like letting the charge drop so low so I don't know if that full balancing charge affected the range indication.

 

[Rolfe]

I do mine every few months and I've never had any worries or strange behaviour at low SoC.

 

[Mouss]

Thread 'How Low Can You Go .... (SoC)'

Dec 19, 2024

It's GOM calibration and balance time, so I ran the car down low and left it for a couple of hours before starting to charge. This was a photo I took immediately before starting the charge:

Anyone else gone lower?

PS - I checked the SOH with Car Scanner and it said 92.66%. I'll check again once charging and balancing is all done.

• siteguru
• battery calibration charging electric mg4
• Replies: 24
• Forum: MG4 EV Forum

• 

 

[siteguru]

Ah - so it was 2% I got down to, not 1%.

 

[Wizard of Oz]

Ah - so it was 2% I got down to, not 1%.

So, you had twice the range... Nothing to worry about, then.

 

[gravity]

People report, that there is still 10-15kms left until full stop on LFPs. If i look at the carscanner, the display soc and bms soc differ about 3%. So right in line. I'd wager there's about 1.5-2kWh of bottom buffer below 0%. So unless you go crazy with accelaration below 0% display, you're probably safe for at least a few kms.

Thanks @hojnikb, Please share a picture showing Car scanner BMS SoC vs Displayed SoC (at any state). You will be doing the doubters out there a great service. ;-). Thanks in advance

 

[hojnikb]

Thanks @hojnikb, Please share a picture showing Car scanner BMS SoC vs Displayed SoC (at any state). You will be doing the doubters out there a great service. ;-). Thanks in advance

Will do. My car is quirky tho, as i plug in the vgate, i lose drivers window controls

 

[hojnikb]

When mine reached 9% SoC , the range changed to three dashes. I was only a mile or so from home so I didn't worry - but it's not really a very useful indicator!

I suspect, that when you get three dashes, BMS might not be sure in itself, what the actual state of charge (or rather how much usable kWh there is) so to be safe, it just show three dashes.

At least, that'd make sense.

 

[Rolfe]

That's why I asked about the long charge. That's supposed to make the BMS more sure of itself.

 

[hojnikb]

That's why I asked about the long charge. That's supposed to make the BMS more sure of itself.

It certanly should, yeah.

 

[hojnikb]

Thanks @hojnikb, Please share a picture showing Car scanner BMS SoC vs Displayed SoC (at any state). You will be doing the doubters out there a great service. ;-). Thanks in advance

Here is it. Displayed SOC on the dashboard was 11% at the time. I suspect it's lagging a bit compared to actual BMS data.

So yeah, at low states of charge there's about 4% difference displayed vs actual %. So i'd guess when the SOC reaches zero, the car might stop or be actually empty.

Guess i'll have to try.

 

[Mouss]

My Luxury (Trophy) with SoH at 95,1%
40300 km (not miles)

I drove 405 km with 100% battery at the beginning.