Battery and range Gen 1 ZS EV

[chris69]

Hi all. I have just bought a second hand ZS EV Gen 1 with 20K miles. The car is awesome, but I have a couple of questions regarding the battery SOH and range in such a low mileage car.

My OBD scanner shows the SOH is 92.13% - is this to be expected at this age and mileage?

The battery balanced last night on the 2.3kW charger. This morning the scanner shows 93% SOC (even though it charged fully and stopped charging itself) and 151 miles range (after resetting both trips. The battery voltage is 450V. Does this sound normal?

Pictures attached for info.

 

[Jomarkh]

There were a number of updates to the ZS BMS issues so check that they have been done.
If it has been on a lot of rapid chargers then that would put the cells out of balance.
Maybe worth taking the battery down to 50-60% then battery balance again, you may have to repeat this a few times.
How long do you think it took to battery balance?
What does the GOM say if you reset all the trip counters?

 

[chris69]

I’ve no idea how the previous lane looked after the battery unfortunately. The range is after resetting both trips. The car was drawing 300W for between 2 and 3 hours at the end of the charge so I’m assuming that’s how long it took to balance.

I asked my local MG dealer about any outstanding software updates and they said they don’t think MG had released any for a long time, but if they had it would not be covered by warranty. They also said they won’t do the comfort 2 update any more.

 

[Coulomb]

My OBD scanner shows the SOH is 92.13% - is this to be expected at this age and mileage?

That's about the expected. The battery always deteriorates more at the start, then slows down.

This morning the scanner shows 93% SOC (even though it charged fully and stopped charging itself)

The latest firmware has nearly all the buffer at the top, so 100% displayed SoC is 93.2% real SoC, and 0% displayed is about 0.5% real SoC. Your scanner is showing you real SoC. So this is completely expected; no need to fiddle with discharging and recharging.

The battery voltage is 450V. Does this sound normal?

The latest firmware aims for 449 V. My Mark 1 ends up at about 452 V; I have no idea why it "misses" its target like that. Again, totally normal.

 

[chris69]

That's about the expected. The battery always deteriorates more at the start, then slows down.


The latest firmware has nearly all the buffer at the top, so 100% displayed SoC is 93.2% real SoC, and 0% displayed is about 0.5% real SoC. Your scanner is showing you real SoC. So this is completely expected; no need to fiddle with discharging and recharging.


The latest firmware aims for 449 V. My Mark 1 ends up at about 452 V; I have no idea why it "misses" its target like that. Again, totally normal.

Thanks that’s pretty much what I was hoping and all makes perfect sense.