Help! Ran both batteries down!

S

Stoob

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As befits a novice ev driver, I ran my drive (hv) battery down on a drive to Gatwick airport (Ok, Waze may have helped). Got car returned to home in flatbed but can’t reach my home charger with cable.
Should I expect any problem recharging with the granny charger?
2020 ZS ev.
Sorry about telegraph style message; I started out at 2am and now it’s 6:25.

Update at 10:55 am: I have plugged the slow (granny) charger in. Power light on charger lit but not charging. Car display reads ‘Connected but not charging’. I have tried connecting in several sequences (power off- plug in - lock - power on; same starting with power on; power off - plug in - power in - lock) but get the same result.
 
Last edited:
Stoob said:
As befits a novice ev driver, I ran my drive (hv) battery down on a drive to Gatwick airport (Ok, Waze may have helped). Got car returned to home in flatbed but can’t reach my home charger with cable.
Should I expect any problem recharging with the granny charger?
2020 ZS ev.
Sorry about telegraph style message; I started out at 2am and now it’s 6:25.
Click to expand...
Hi, can you pop it on the granny EVSE to get a bit of juice in it?
Or push the car nearer your 7kW EVSE?
 
Last month I picked up our damaged Leaf from Storage (written off) and took it back home. Since the door is stuck and car thinks its open it keeps the lights on and it ran down 12V battery.

EVSE wouldn't start charging and it was down to flat 12V battery. I picked up a 12V battery charger from Amazon. Disconnected the car from 12V battery and charged it for 5 hours. When I plugged it back it all was well and I managed to charge the car.

In case you have problems something worth trying
 
Jomarkh said:
Hi, can you pop it on the granny EVSE to get a bit of juice in it?
Or push the car nearer your 7kW EVSE?
Click to expand...
Neither. The granny charger isn’t charging and my drive is on a slope with the car reversed in.

hermitdave said:
Last month I picked up our damaged Leaf from Storage (written off) and took it back home. Since the door is stuck and car thinks its open it keeps the lights on and it ran down 12V battery.

EVSE wouldn't start charging and it was down to flat 12V battery. I picked up a 12V battery charger from Amazon. Disconnected the car from 12V battery and charged it for 5 hours. When I plugged it back it all was well and I managed to charge the car.

In case you have problems something worth trying
Click to expand...
Thanks. I’ll try this. I have a 5000A battery pack that I’ll connect.
 
That should work as the car needs a 12 volt supply to initiate the contactors on the HV battery to start charging from the granny charger.
 
Stoob said:
I’ve connected it and waiting. Seems odd though: the car unlocks and displays the ‘not charging’ message.
Click to expand...
You dont have it on a charge timer by chance. (The car, not the charger offcourse)

If it is set to charge at a specific time, it will not start before that time has arrived.
 
hmadsen said:
You dont have it on a charge timer by chance. (The car, not the charger offcourse)

If it is set to charge at a specific time, it will not start before that time has arrived.
Click to expand...
No, I don’t think so. I’ve never seen such an option. This is a 2020 version. Anyway, I have a Rolec QUBEV smart home charger which can be scheduled, though I usually just use the app.

2 hours later: 12v battery on charger for two hours. Sparks when reconnecting neg terminal, so charge is there. Plugged in, locked, switched on. Still ‘Connected but not charging’. Should charging start immediately? I know there’s a random waiting period with my 7kw charger.

Thought: If the 12v battery is sufficiently charged, could I use its power to turn my car round? Then I could connect to 7Kw charger.
 
Last edited:
Stoob said:
No, I don’t think so. I’ve never seen such an option. This is a 2020 version. Anyway, I have a Rolec QUBEV smart home charger which can be scheduled, though I usually just use the app.

2 hours later: 12v battery on charger for two hours. Sparks when reconnecting neg terminal, so charge is there. Plugged in, locked, switched on. Still ‘Connected but not charging’. Should charging start immediately? I know there’s a random waiting period with my 7kw charger.

Thought: If the 12v battery is sufficiently charged, could I use its power to turn my car round? Then I could connect to 7Kw charger.
Click to expand...
If i were you i might try this.

1. Charge the 12V battery until it has sufficient charge to run the Low voltage stuff in the car (2 hours should be sufficient, depending on the charge capabilities of the charger).

2. Remove the granny charger from the charge port

3. Remove the negative battery terminal from the low voltage battery and wait 5 minutes.

3. Reconnect the battery and let all of the cars systems boot up.

4. Connect the granny charger and try to see if it will charge.


PS. NO, the car will NOT be able to drive off of the low voltage battery, only the high voltage traction battery is able to make the car move.

Things to listen for and watch out for

When you "start" the car after having charged the low voltage battery, do you get a Ready and do you hear the "klonk" as the contactor for the HV battery kicks in.

What does the car say about charge on the high voltage battery...What is the stated % in the car ?


All of the charge, disconnect, reconnect and so on is to "reset" all of the computers.

Maybe if the voltage was low, they started up in some weird state and the "reboot" solves the problem of it not wanting to restart....Remember most stuff in the car has its own "computer" so if the onboard charger software is running in some weird state, it might not start charging even if the rest of the car appears fine.
 
hmadsen said:
If i were you i might try this.

1. Charge the 12V battery until it has sufficient charge to run the Low voltage stuff in the car (2 hours should be sufficient, depending on the charge capabilities of the charger).

2. Remove the granny charger from the charge port

3. Remove the negative battery terminal from the low voltage battery and wait 5 minutes.

3. Reconnect the battery and let all of the cars systems boot up.

4. Connect the granny charger and try to see if it will charge.


PS. NO, the car will NOT be able to drive off of the low voltage battery, only the high voltage traction battery is able to make the car move.

Things to listen for and watch out for

When you "start" the car after having charged the low voltage battery, do you get a Ready and do you hear the "klonk" as the contactor for the HV battery kicks in.

What does the car say about charge on the high voltage battery...What is the stated % in the car ?


All of the charge, disconnect, reconnect and so on is to "reset" all of the computers.

Maybe if the voltage was low, they started up in some weird state and the "reboot" solves the problem of it not wanting to restart....Remember most stuff in the car has its own "computer" so the if the onboard charger software is running in some weird state, it might not start charging even if the rest of the car appears fine.
Click to expand...
Thank you. So, I charged the 12v battery with the negative terminal decoupled. The granny charger was not plugged in at the charging port. After reconnecting the negative terminal, I checked the instrument cluster. The 12v battery is now showing 14+v on the dash. I reconnected the granny charger, locked the car and turned the power on. Still connected but not charging. The Hv battery is still reading ‘- -‘. I’ve attached a picture. The main battery indicator is a single line flashing. I don’t recall hearing a distinctive sound of the contactor but the sounds are much like I remember them.
 

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I don't know if the ZS is the same, but on the MG4, if you go into charging on the infotainment screen there is a start charging button.
 
Stoob said:
Thank you. So, I charged the 12v battery with the negative terminal decoupled. The granny charger was not plugged in at the charging port. After reconnecting the negative terminal, I checked the instrument cluster. The 12v battery is now showing 14+v on the dash. I reconnected the granny charger, locked the car and turned the power on. Still connected but not charging. The Hv battery is still reading ‘- -‘. I’ve attached a picture. The main battery indicator is a single line flashing. I don’t recall hearing a distinctive sound of the contactor but the sounds are much like I remember them.
Click to expand...
I have just discovered that I have something called MG Assist. Phoned them and they say they are sending someone around. Funny. I’ve spent the whole day talking to my garage and on here and in my last call to the garage they mentioned MG Assist. I can only conclude that everyone assumed I knew but was out of cover. You must think me the greatest idiot ever to draw breath. I do - but because I let the battery go flat. Never again.
This is a great forum and you have all been very kind. Thanks. I’ve put MG Assist in my favourites list!
 
Stoob said:
I have just discovered that I have something called MG Assist. Phoned them and they say they are sending someone around. Funny. I’ve spent the whole day talking to my garage and on here and in my last call to the garage they mentioned MG Assist. I can only conclude that everyone assumed I knew but was out of cover. You must think me the greatest idiot ever to draw breath. I do - but because I let the battery go flat. Never again.
This is a great forum and you have all been very kind. Thanks. I’ve put MG Assist in my favourites list!
Click to expand...
Did MG Assist get you charging then? Would be good if you know what they did in case others find themselves in a similar situation.
 
mattdav said:
Did MG Assist get you charging then? Would be good if you know what they did in case others find themselves in a similar situation.
Click to expand...
MG Assist was brilliant. They arrived a hour or so after my first call. The guy did checks but couldn’t get the granny charger working. In the end, he chanced it and drove the car off the driveway, turned it round and got it up facing the right way before it died - just. It is now charged and running as normal.
Three lessons:
1) Trust the car; if it says ‘stop the car’, stop the car. I read on a thread somewhere in this forum about someone who ran their MG EV for 10 miles after the warning. Well, I tried it and it ain’t worth it.
2) Call MG Assist. I don’t know whether it can be renewed once the free period runs out but it’s worth it.
3) Allowing for the weather, make sure the car has sufficient charge. I thought I’d have 15 miles left but it was very cold. AND allow for map errors: Waze drove me around Gatwick north terminal 3 times before I found the slip road to south terminal. I probably would have made it home.

Is there a thread for this?
Zapmap refused to connect me when I looked for a charging point. In a premium member, signed in and have always connected through CarPlay before but suddenly it told me I was not. First time. I could have got to a charger at that point. By the time I tried Electroverse and Shell it was too late. Has anyone else been affected? I’ve been in touch with them but…it’s a company.
 
Stoob said:
1) Trust the car; if it says ‘stop the car’, stop the car. I read on a thread somewhere in this forum about someone who ran their MG EV for 10 miles after the warning. Well, I tried it and it ain’t worth it.
Click to expand...

Yes!
Stoob said:
2) Call MG Assist. I don’t know whether it can be renewed once the free period runs out but it’s worth it.
Click to expand...

If you service your car annually with MG garage, you get free AA cover (MG assist) for a year. Sometimes you need to remind the dealer to activate it.
Stoob said:
3) Allowing for the weather, make sure the car has sufficient charge. I thought I’d have 15 miles left but it was very cold. AND allow for map errors: Waze drove me around Gatwick north terminal 3 times before I found the slip road to south terminal. I probably would have made it home.
Click to expand...

My rule is - as soon as the warning pops up that the main battery is low (somewhere below 30%) and I'm not 10 min away from home - PANIC and charge!
 
fred12345 said:
Yes!


If you service your car annually with MG garage, you get free AA cover (MG assist) for a year. Sometimes you need to remind the dealer to activate it.


My rule is - as soon as the warning pops up that the main battery is low (somewhere below 30%) and I'm not 10 min away from home - PANIC and charge!
Click to expand...
Thank you. Lots of valuable info here. All in all, my stupidity has taught me much.
 

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