Losing charge whilst parked

[suzyj]

I’ve had my ZS EV for a month and it’s losing charge regularly just sat on drive, around 20% at times! Today I did a 30 mile round trip and it started off at 80% charge and ended in red zone at 18%! Dealer has checked battery and says there isn’t a fault. I’m so distraught by this car that I’m heading down a consumer protection act route. Has anyone encountered this issue and if so what action did you take? It’s so unreliable and is impacting hugely. TIA

 

[N2STY]

It sounds like a standard range car?
Have you been charging it to 100% when ever you can?

 

[Jomarkh]

That does seem a lot to loose overnight and on a short trip.
Did you have it from new and have you done a battery balance by leaving it connected for a few hours after reaching 100%?
What sort of m/kWh are you getting? Mine was under 3 when it was really cold.

 

[suzyj]

It sounds like a standard range car?
Have you been charging it to 100% when ever you can?

Hi yes it’s standard range and mostly charge to 100%. It literally dropped from 66% to 39% whilst I sat in office from 8am to 1pm

 

[suzyj]

That does seem a lot to loose overnight and on a short trip.
Did you have it from new and have you done a battery balance by leaving it connected for a few hours after reaching 100%?

It’s madness, it’s been like this since collecting it

 

[N2STY]

That does seem a lot to loose overnight and on a short trip.

I would be worried if it's a LR
But them SR if you don't start at 100% can be very frustrating

 

[suzyj]

That does seem a lot to loose overnight and on a short trip.
Did you have it from new and have you done a battery balance by leaving it connected for a few hours after reaching 100%?
What sort of m/kWh are you getting? Mine was under 3 when it was really cold.

Yes bought from new. I haven’t left it connected at 100%, do you suggest I try that? I’m getting between 3.4 -3.7 m/kWh even this week in warmer weather

 

[suzyj]

I would be worried if it's a LR
But them SR if you don't start at 100% can be very frustrating

So every journey should start at 100%?

 

[Jomarkh]

Leave it connected the power will drop to 300-500w until the balance is complete.
3.4 -3.7 is good for this week.
But dropping from 66-39% is very poor. Was it shut off and powered down?

 

[N2STY]

Not really only to see better range on gom if you say you get to car and it's low after being high the chances are you still got the same range as when you parked the next drop will probably take longer

 

[suzyj]

Leave it connected the power will drop to 300-500w until the balance is complete.
3.4 -3.7 is good for this week.
But dropping from 66-39% is very poor. Was it shut off and powered down?

It’s charging on the slow charge via normal plug so should I just leave it connected all night?
As far as I know it was all turned off, but im questioning myself, am I missing something maybe when I think I’ve turned it off?

 

[N2STY]

But dropping from 66-39% is very poor. Was it shut off and powered down?

Biggest problem with LFP batterys 30% to 80% same voltage so BMS just don't know

 

[suzyj]

Not really only to see better range on gom if you say you get to car and it's low after being high the chances are you still got the same range as when you parked the next drop will probably take longer

It dropped another 20% when I then drove home, around 13 miles

 

[suzyj]

Biggest problem with LFP batterys 30% to 80% same voltage so BMS just don't know

I don’t understand this sorry, I’m a complete novice!

 

[N2STY]

I don’t understand this sorry, I’m a complete novice!

Just to make simple a LR say 2v full and 1v empty 80% battery would be 1.8v and 50% is 1.5v
But SR full is 2v and empty is 1.4v but 80% battery is 1.8v and 30% is 1.8v so it's hard for the computer to work out charge level

 

[N2STY]

charging on the slow charge via normal plug so should I just leave it connected all night?

Yes when 100% just leave it plugged in over night

 

[IanMG]

I'm wondering if the battery has been set to pre-heat and it isn't turning off, and that is what is draining it whilst you leave it at work etc.?
What does it say on the dash when looking at motor/battery voltage and current usage?
The car will have to be in the 'ready' state, but it should only be drawing 10 - 17 amps when sitting there in Drive and not going anywhere.
If it is appreciably more than that, by approx 15 amps or more, then the HV battery has a drain on it which isn't normal. The battery pre-heat is 7Kw or so about 25 - 32 amps.
Ask your dealer to check residual consumption.

 

[Lovemyev]

Yes when 100% just leave it plugged in over night

Agreed, remember @suzyj that the balancing cycle does not commence until the HV battery has reached 100% SOC first.
Just leave it plugged in and it will automatically turn off the supply from the Granny lead, when the balance process has completed.

 

[N2STY]

The battery pre-heat is 7Kw or so about 25 - 32 amps.

Your getting confused with cabin heater battery heater uses about 2kw
Edit sorry 3kw for battery heater the cabin heater is occasionally 7kw sometimes more but mainly a lot less only 7kw for a few seconds

 

[Tim Green]

I have left my car for a week and it didn't seem to lose any battery power. GOM was the same as when I left it.