Granny won't wake up !

[PristDean]

So having made use of my Granny charger to stabilise charging due to the 'Peek a Boo' sunshine in the UK right now... I have found that after charging during the day, if I leave Granny plugged in overnight but not charging, then try and start a charge the next day via the iSmart app, it fails. Communicates with the car,a car icon appears, then car icon changes to a bicycle icon, then fails.
Unlocking and re-locking the car makes no difference. The only way to bring Granny back to the world of charging is to either switch off at the wall, then 10 seconds later switch on again, or open the car and sit inside it to bring up the info screen. In both cases charging starts again via the app.
Pain in the butt to have to do that each day ! Anyone else come across the same ?

 

[GaryMG4]

Not left it overnight but have stopped charging during the day and restarted via the app without any issues. Maybe a power saving feature in the 'box', perhaps a smart socket will help?

 

[PristDean]

Not left it overnight but have stopped charging during the day and restarted via the app without any issues. Maybe a power saving feature in the 'box', perhaps a smart socket will help?

Good point... I have plenty of smart sockets lying about, so will give that a go. Thanks

 

[Tigger]

Good point... I have plenty of smart sockets lying about, so will give that a go. Thanks

Please let us know how this works out. Can a smart socket sustain a continuous load of 10-13 amps for maybe 6 hours without overheating?

 

[PristDean]

Please let us know how this works out. Can a smart socket sustain a continuous load of 10-13 amps for maybe 6 hours without overheating?

So far so good, the plug I am using has an energy monitoring feature and scheduling too. Only used 2.02 Kwh today and the plug has been running for 4.7 Hrs.
Have scheduled it to turn itself off at sunset, which it has done. I will then manually power it on again when I need it.
When I do a charge next, i'll monitor if it gets hot or not. It's in my garage.

 

[Ian Key]

Please let us know how this works out. Can a smart socket sustain a continuous load of 10-13 amps for maybe 6 hours without overheating?

I have a couple of different makes of smart plugs. Some are rated at 2kWh and some at 3kWh so read their specs

 

[PristDean]

Tapo P110: Maximum Load: 2990W, 13 A, Which I think most modern plugs should support for safety, given household appliances they attach to could pull up to 3kwh.. Kettle etc

 

[PristDean]

Mmmm... the perils of using a Granny charger on and off without regular vehicle usage.
So my car has been sat over the weekend with me having a Granny charger attached a periodically starting and stopping charges via iSmart.
Today the car is dead and 12v battery depleted. Lesson learnt then, but that seems a fast depletion to render the car dead after say ten iSmart interrogations ! Does using iSmart have a big impact on the 12v battery ?

 

[tsedge]

Mmmm... the perils of using a Granny charger on and off without regular vehicle usage.
So my car has been sat over the weekend with me having a Granny charger attached a periodically starting and stopping charges via iSmart.
Today the car is dead and 12v battery depleted. Lesson learnt then, but that seems a fast depletion to render the car dead after say ten iSmart interrogations ! Does using iSmart have a big impact on the 12v battery ?

No, it shouldn't, but using it does wake the car up and it takes a long time to go back to sleep properly. If you are leaving the car for a long time, best to let it snooze and not use the app.

However, ten such interrogations only over a weekend should not cause this problem, so either there's parasitic drain somewhere or your 12V battery was already weak.

The car should charge the 12V battery when it is low, maybe this is not working as it should?

 

[PristDean]

No, it shouldn't, but using it does wake the car up and it takes a long time to go back to sleep properly. If you are leaving the car for a long time, best to let it snooze and not use the app.

However, ten such interrogations only over a weekend should not cause this problem, so either there's parasitic drain somewhere or your 12V battery was already weak.

The car should charge the 12V battery when it is low, maybe this is not working as it should?

Thanks, interesting, so if the 12v battery depletes the NMC should top it up ? If that's the case, it didn't, so another fault !

But.. just had a thought @tsedge ... with the car connected to a charger, the NMC battery is disconnected I believe (as shown on the dash).. so would that render it incapable of topping up the 12v ?

 

[tsedge]

Thanks, interesting, so if the 12v battery depletes the NMC should top it up ? If that's the case, it didn't, so another fault !

But.. just had a thought @tsedge ... with the car connected to a charger, the NMC battery is disconnected I believe (as shown on the dash).. so would that render it incapable of topping up the 12v ?

I don't know, sorry.

 

[PristDean]

I don't know, sorry.

Ok, I'm at a dealers on Thursday so will ask. If this is the case, it's a bit of a 'Gotcha' to look out for... leaving your car connected to a charger and using iSmart will drain your 12v quickly.

 

[tsedge]

Ok, I'm at a dealers on Thursday so will ask. If this is the case, it's a bit of a 'Gotcha' to look out for... leaving your car connected to a charger and using iSmart will drain your 12v quickly.

It is certainly possible that it does do this but the car should be able cope with granny charging for a couple of days in any case.

 

[siteguru]

One way to check would be to connect to the granny charger and start charging, open the iSMART app and scan the car ... look at the voltage reading for the 12V battery. If it's not topping up whilst on the granny then it'll show 12.5V or less; if it is then it'll show more like 13.9V.

(Apologies if this is already mentioned - I've not read every post in the thread).

 

[PristDean]

One way to check would be to connect to the granny charger and start charging, open the iSMART app and scan the car ... look at the voltage reading for the 12V battery. If it's not topping up whilst on the granny then it'll show 12.5V or less; if it is then it'll show more like 13.9V.

(Apologies if this is already mentioned - I've not read every post in the thread).

Thanks, will give it a try once I have the 12v charged back up.
However, if I left the Granny attached to the car and not charging, I assume that would cause a 12v drain upon using iSmart. But as you say, once charging occurs, the 12v should charge back up from the NMC batt, which i'll check.

 

[Ian Key]

I seem to remember when my car's been charging on my Zappi the 12v battery on the app has shown 14.4 volts

 

[Jto]

So far so good, the plug I am using has an energy monitoring feature and scheduling too. Only used 2.02 Kwh today and the plug has been running for 4.7 Hrs.
Have scheduled it to turn itself off at sunset, which it has done. I will then manually power it on again when I need it.
When I do a charge next, i'll monitor if it gets hot or not. It's in my garage.

Hi
please could you show a photo of you smart plug or socket, I have one from BG I use to charge my PHEV. Could i suggest that when you battery is full and stopped charging and balancing that you remove the granny plug from the car and that should then keep the 12v battery topped up.

 

[PristDean]

Hi
please could you show a photo of you smart plug or socket, I have one from BG I use to charge my PHEV. Could i suggest that when you battery is full and stopped charging and balancing that you remove the granny plug from the car and that should then keep the 12v battery topped up.

Hi, No it doesn't. On an MG4 the 12v is charged when charging the main battery is in progress, not when stopped. If you look at the iSmart app it show your 12v at something like 13.8v or 14.3v when its charging, then drop to something like 12.4v when not charging.
I drained my 12v by using the iSmart app and unlocking / locking the car a fair few times (with wing mirrors folding and unfolding) and not enough charging taking place to top it up.

The Smart plug I am using is from TAPO, energy monitoring version P110

Tapo P110 | Mini Smart Wi-Fi Socket, Energy Monitoring | Tapo

Control your home lighting or ceiling fans from anywhere, anytime with the Kasa Smart app. Set automatic schedules and pair with Alexa or Google Assistant for voice control.

www.tapo.com

 

[Jto]

Hi, No it doesn't. On an MG4 the 12v is charged when charging the main battery is in progress, not when stopped. If you look at the iSmart app it show your 12v at something like 13.8v or 14.3v when its charging, then drop to something like 12.4v when not charging.
I drained my 12v by using the iSmart app and unlocking / locking the car a fair few times (with wing mirrors folding and unfolding) and not enough charging taking place to top it up.

The Smart plug I am using is from TAPO, energy monitoring version P110

Tapo P110 | Mini Smart Wi-Fi Socket, Energy Monitoring | Tapo

Control your home lighting or ceiling fans from anywhere, anytime with the Kasa Smart app. Set automatic schedules and pair with Alexa or Google Assistant for voice control.

www.tapo.com

Thanks for the link, I would say the 12v battery should stand up to lock and unlocking hundred of times, I do not know what the actual amps of the battery but would think be around 50 to 60amp hour battery.
Your 12v battery is changed only when in ready mode on the MG 4 ( see user manual 12v battery maintenance ) so are you a low user of the car ie short journey and not used every day. If so you may not get the battery topped back up enough to keep a high amp hour output. I work with mobility scooter which run on 24v and when the battery’s are charged I like to see 25.7/9 v on a meter. The meter in the cars are not very accurate and on a 12v battery like like to see over 13v and that reading I would take some time after charging to get a accurate reading with a meter.

i can get a reading of 25v on a scooter but the scooter may only do 1 mile then start to stop even it’s been on charge all night, you see because it can not get the amperage back up to the rate of the battery’s they have not got the muscle to take the scooter any distance. its not the voltages as everyone thinks. I test the battery by a tester that can put a load on to the battery and see how long it takes to discharge the battery, This is why some people are now putting a deep cell battery on cars now as they are designed to release power slower and longer that a normal car battery which release power quickly like cranking a car engines.

 

[andyinyork]

Hi all picked up my new mg4 trophy yesterday and note granny charger cable is quite short and won’t reach my garage where 3 pin plug is located.
My wife has a Volvo v40 supplied with a longer cable which willl reach my car charging point will it work or do I have to use an mg one?