ZS EV Mk2 12V battery auto-top-up?

[Peter WA]

When researching the differences between Mk1 and Mk2 I came across the information that the Mk2 can top up the 12V battery from the HV battery when the car is stationary for a while and voltage of the 12V battery drops.

Has anyone actually observed this happening?

Is it is triggered by a specific voltage of the 12V battery, or is it time based (i.e. once a week)?

Planning ahead for a longer absence later this year, wondering whether the top-up is reliable enough or whether I should hook the 12V up to a charger.

 

[JCFlippen]

If the Gen 2 is switched on in Ready mode then the 12v battery is charged up to 14.1v from whatever.

 

[Peter WA]

If the Gen 2 is switched on in Ready mode then the 12v battery is charged up to 14.1v from whatever.

I wouldn't leave the car in Ready mode for a few weeks though.

And actually, the lowest 12V voltage I've observed was when the car was in Ready mode for a few hours, then decided to disconnect the HV battery and still drain the 12V at an alarming rate.

 

[Peter WA]

And actually, the lowest 12V voltage I've observed was when the car was in Ready mode for a few hours, then decided to disconnect the HV battery and still drain the 12V at an alarming rate.

Here's a chart of that episode. Not happy, big software bug there!

 

[jjbb]

When researching the differences between Mk1 and Mk2 I came across the information that the Mk2 can top up the 12V battery from the HV battery when the car is stationary for a while and voltage of the 12V battery drops.

Has anyone actually observed this happening?

Is it is triggered by a specific voltage of the 12V battery, or is it time based (i.e. once a week)?

Planning ahead for a longer absence later this year, wondering whether the top-up is reliable enough or whether I should hook the 12V up to a charger.

I’ve had my zs ev one day and I have a message saying 12v very low. Even after a long drive today. Help please. Also what is “ready mode”?

 

[Peter WA]

I’ve had my zs ev one day and I have a message saying 12v very low. Even after a long drive today. Help please. Also what is “ready mode”?

It could be measuring wrong, giving a false alert, or it could fail to charge the 12V battery.

If you have a voltmeter, measure directly at the battery, or there are very cheap devices that plug into what used to be called the cigarette lighter socket that show voltage.

When the car is 'ready' to drive, i.e. turned on, the voltage should be well over 13V, up to 14.6V. The more depleted the battery was before turning on, the higher it will stay for longer.

Measuring when 'off' is a bit more tricky with all the electronics. Opening the hood will keep some things alive, reducing the voltage right away. It should still be well over 12V though.

 

[Striker]

Peter, I'm pretty sure that the MK2 does manage it's 12V when the car is parked up and off. I believe that it tops up when the voltage drops to a certain level
This got raised quite a bit during the (UK) summer, when we were leaving our cars, as far as I know, nobody had any problems

 

[jjbb]

It could be measuring wrong, giving a false alert, or it could fail to charge the 12V battery.

If you have a voltmeter, measure directly at the battery, or there are very cheap devices that plug into what used to be called the cigarette lighter socket that show voltage.

When the car is 'ready' to drive, i.e. turned on, the voltage should be well over 13V, up to 14.6V. The more depleted the battery was before turning on, the higher it will stay for longer.

Measuring when 'off' is a bit more tricky with all the electronics. Opening the hood will keep some things alive, reducing the voltage right away. It should still be well over 12V though.

Thanks for this information Peter. I think I will have to get mg to look into this for me.