Voltage shows 400

[navneeth1986]

Hi Guys,

I charged my car to 100% yesterday. The voltage shows 400, is this normal?


Kind Regards
Nav

 

[Coulomb]

The voltage shows 400, is this normal?

Which model? Presumably ZS to post in this forum, but classic or SR or LR?

 

[navneeth1986]

Which model? Presumably ZS to post in this forum, but classic or SR or LR?

Its the MG ZS EV 2022 model. short range.

 

[Coulomb]

short range

Standard range. That's the likely new chemistry that we know little about.

Is this voltage when in ON mode (not ready, no foot on brake)?

The SR is supposed to have the higher battery voltage. If so, the LR model must have very low battery voltage.

What do other SR model owners see with 100% SoC?

 

[navneeth1986]

Standard range. That's the likely new chemistry that we know little about.

Is this voltage when in ON mode (not ready, no foot on brake)?

The SR is supposed to have the higher battery voltage. If so, the LR model must have very low battery voltage.

What do other SR model owners see with 100% SoC?

Yes, When in ON mode.

 

[navneeth1986]

Standard range. That's the likely new chemistry that we know little about.

Is this voltage when in ON mode (not ready, no foot on brake)?

The SR is supposed to have the higher battery voltage. If so, the LR model must have very low battery voltage.

What do other SR model owners see with 100% SoC?

Weirdly I have another issue on the back of this. I used a granny charger last night, it was 65%, and scheduled a charge for 4 hours. It was 100% when complete. I was surprised by this.

 

[riizzle]

400 is what I see too on my 2022 SR

 

[Lovemyev]

I think that is has been suggested that the face lift model, runs on a lower HV battery voltage that is similar to the MG5 model.
Some where a little over 400 volts.
I think this has been changed to match the different drive motors on the face lift models.
This may explain why the power delivery on the face lift model is more linear than on the original / classic ZS EV model.

 

[Coulomb]

400 is what I see too on my 2022 SR

Does it stay at exactly 400 after charging, or does the voltage relax with time, say a few hours after charging, but no driving?

I ask because that's a characteristic of LFP cells, they quickly fall in voltage to one of two plateaus, and that relaxing is what I believe makes them last longer. The longer that they stay away from high cell voltage, the longer they will last.

Is it perhaps the case that during charging, the voltage is higher, say around a peak of 410V, and they relax back to 400V by the time you look?

 

[riizzle]

Does it stay at exactly 400 after charging, or does the voltage relax with time, say a few hours after charging, but no driving?

I ask because that's a characteristic of LFP cells, they quickly fall in voltage to one of two plateaus, and that relaxing is what I believe makes them last longer. The longer that they stay away from high cell voltage, the longer they will last.

Is it perhaps the case that during charging, the voltage is higher, say around a peak of 410V, and they relax back to 400V by the time you look?

I couldn't tell you exact voltages off the top of my head, but yes what you're saying is right. When charging or on KERS it's around 405-410, and when not charging it's around 390s

 

[Coulomb]

When charging or on KERS it's around 405-410, and when not charging it's around 390s

Woo hoo. That sounds like LFP. Good to have that confirmation.

 

[D3D]

I looked up the battery barcode of my std range & it came up as LFP. I’m well pleased. I’d been wondering why the 80% charge limit ability was disabled & goes straight to 100% I guess all us standard rangers can now pretend we’ve all got cut price Tesla SRs! Technology on our driveways!?

 

[r0b1n68]

My standard model showed 415 volts this morning after a full charge

 

[Coulomb]

My standard model showed 415 volts this morning after a full charge

Ah. It looks to me that they charge to some value greater or equal to 415V, and the battery voltage relaxes from there over a period of minutes to hours. So unlike the NMC chemistry that retains the voltage it was charged to, LFP will settle to a value somewhat less than the peak voltage. Possibly that settled voltage is around 400V, though it may well depend on the battery temperature.

While possibly unsettling for those used to the other chemistry, I believe that this has no effect on SoC.

So now when SR owners report voltage after a charge, perhaps they should wait some time (I don't know how long, but I suspect that 2 hours should be enough) after charging is complete before reading the voltage. Of course, one often doesn't know exactly when the charge did finish. I assume that balancing will still happen with the LFP batteries.