Granny Charger woes
Discussion
After 12 months since ordering, we finally picked up a our Nissan Leaf teckna E+ - the run with the bigger battery.
Given the delays we had not sorted out our home charger as it didn't seem sensible to pay / fit something when we did'nt have the car.
For the first week of ownership, we used the public charging up the road, i knew it would be dearer but it would keep us going until home charger fitted.
Week two and we're stil getting used to driving an EV and struggling with the range - from 100% were supported to have 200miles, but wiht the cold weather etc i think we're burning through it quicker than expected.
so we purchased a 3pin granny charger to keep us topped up and last night plugged in to charge the car overnight. Set it to 13A and away we go ....
4am this morning, woken up by our hard wired fire alarms going off.... ran around couldn't find any fires / smoke etc and only thing i could think off was the charger ... ran out, car is fine and fully charged. No fires in the garage but i've unplugged the charger anyway.
muddled head but would the charger on reaching 100% and effectively being done have put some feedback into the elecs and trigged the alarms ? coincident ? Any ideas ?
Given the delays we had not sorted out our home charger as it didn't seem sensible to pay / fit something when we did'nt have the car.
For the first week of ownership, we used the public charging up the road, i knew it would be dearer but it would keep us going until home charger fitted.
Week two and we're stil getting used to driving an EV and struggling with the range - from 100% were supported to have 200miles, but wiht the cold weather etc i think we're burning through it quicker than expected.
so we purchased a 3pin granny charger to keep us topped up and last night plugged in to charge the car overnight. Set it to 13A and away we go ....
4am this morning, woken up by our hard wired fire alarms going off.... ran around couldn't find any fires / smoke etc and only thing i could think off was the charger ... ran out, car is fine and fully charged. No fires in the garage but i've unplugged the charger anyway.
muddled head but would the charger on reaching 100% and effectively being done have put some feedback into the elecs and trigged the alarms ? coincident ? Any ideas ?
We charge our plug in hybrid just from an outside plug on the driveway.
Before that we did charge from an extension lead running from the kitchen for a few months.
We never had any issues doing either with it usually taking around 5hrs for a full charge.
Not a clue about electrics but would have thought you’d be ok granny charging.
Before that we did charge from an extension lead running from the kitchen for a few months.
We never had any issues doing either with it usually taking around 5hrs for a full charge.
Not a clue about electrics but would have thought you’d be ok granny charging.
When you say "set to 13A" where did you set that - in the lead itself? An OEM granny charger will limit charging current to 10A from the mains.
Although we're used to British Standard plugs being rated for 13A they're not really capable of 13A for hours on end, so can tend to get a bit melty.
Although we're used to British Standard plugs being rated for 13A they're not really capable of 13A for hours on end, so can tend to get a bit melty.
oldskoolgent said:
muddled head but would the charger on reaching 100% and effectively being done have put some feedback into the elecs and trigged the alarms ? coincident ? Any ideas ?
I really wouldn’t assume its a coincidence. How old is the house? What kind of state is the electrical wiring in?As someone else has said, even at 13Amps continuous drain things get warm and stay warm.
I tend run the granny charger at 10Amps not 13Amps, yes it’s slower, but puts nearly 30% less demand on any electrical system. I’ve yet to see a 10Amp sustained pull trip any circuit or cause any issues even when plugged into some really really questionable sockets (hanging out of the wall held in place by the actual mains wiring).
Fires from EV charging going wrong due to issues with electrical connectors do happen.
Was the 13A plug of the granny charger warm or hot?
For a hot 13A plug pull out and insert a few times to clean the electrical contacts.
We have 2 PHEV and often charge both at the same time using cheap midnight electricity on the same 32 Amp ring final and we also run the dishwasher, washing machine and tumble dryer on another 32 Amp ring final. All the electrical loads are within the specification for the installation.
You possibly don't know the condition of your house internal wiring which could be using the wrong size cable, loose connections, connected as spurs or have a break in the ring final.
Our granny charger 13A plugs get slightly warm and the cable from the wall to the granny charger gets slightly warm and we use an extension cable for one. We also charge at 10.8A and not the full 13A.
For a hot 13A plug pull out and insert a few times to clean the electrical contacts.
We have 2 PHEV and often charge both at the same time using cheap midnight electricity on the same 32 Amp ring final and we also run the dishwasher, washing machine and tumble dryer on another 32 Amp ring final. All the electrical loads are within the specification for the installation.
You possibly don't know the condition of your house internal wiring which could be using the wrong size cable, loose connections, connected as spurs or have a break in the ring final.
Our granny charger 13A plugs get slightly warm and the cable from the wall to the granny charger gets slightly warm and we use an extension cable for one. We also charge at 10.8A and not the full 13A.
Did all your electrics stay on? When we first started using a granny charger, it would trip our RCD every time it started charging, and sometimes when it finished. Something about feedback from the switch mode charger and “the wrong type of RCD”. Rewiring the granny charger on to a separate circuit and fitting new “corrrect type” RCDs fixed it.
The same or similar effect may be upsetting your smoke alarms.
The same or similar effect may be upsetting your smoke alarms.
There seem to be two possibilities:
a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm
Charging at 13A is a bit controversial, in that some manufacturers sell three-pin chargers which do so, others sell devices limited to a max of 10A and threaten death & destruction if you go any higher.
Eg https://toughleads.co.uk/collections/ev-electric-v...
I'd also suggest checking the main fusebox etc where the meter is, the socket the charger's connected to, and the charger plug and charger itself to see how warm/hot they are after 30-45 mins charging, just to check.
It's possible if you've bought a cheaper charger that might be causing the electrical issue on cut-off.
Tbh if I were you I'd probably just reduce the current as much as possible while still having the car sufficiently charged when you need it, and wait it out until you get the proper charger fitted - the electrician who does so should also check out the main fusebox etc to ensure it's all adequate to support the higher current.
On the lower than expected range, it's likely caused by cabin heating. If you want better efficiency in the winter you can reduce the cabin temp you set and use heated seats / steering wheel (if your car has them) to keep warm instead. However if you don't need to drive 200 miles before you next charge, you're probably best to just drive it as normal and accept the higher power usage in winter. Lots of short trips often see more energy used, again for heating the car up from cold.
The other factor with efficiency is that it really drops off with speed, i.e. 50, 60 and 70mph are quite different efficiencies.
a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm
Charging at 13A is a bit controversial, in that some manufacturers sell three-pin chargers which do so, others sell devices limited to a max of 10A and threaten death & destruction if you go any higher.
Eg https://toughleads.co.uk/collections/ev-electric-v...
toughleads said:
Some EV granny chargers have a button to adjust the charge rate, which should never exceed 10A. Unfortunately, non-compliant units sold on major online market places sometimes allow 13A to be selected. This is dangerous and likely to lead to damage to the plug on the charger, extension lead or socket.
I'd suggest you try at 10A for a bit and see if the same thing occurs. If possible I'd also suggest charging while someone is awake in the house, just in case and to give you a better chance to investigate if it happens again, but if not then try reducing the current to spread out the charging time as long as possible until whenever you need to use the car.I'd also suggest checking the main fusebox etc where the meter is, the socket the charger's connected to, and the charger plug and charger itself to see how warm/hot they are after 30-45 mins charging, just to check.
It's possible if you've bought a cheaper charger that might be causing the electrical issue on cut-off.
Tbh if I were you I'd probably just reduce the current as much as possible while still having the car sufficiently charged when you need it, and wait it out until you get the proper charger fitted - the electrician who does so should also check out the main fusebox etc to ensure it's all adequate to support the higher current.
On the lower than expected range, it's likely caused by cabin heating. If you want better efficiency in the winter you can reduce the cabin temp you set and use heated seats / steering wheel (if your car has them) to keep warm instead. However if you don't need to drive 200 miles before you next charge, you're probably best to just drive it as normal and accept the higher power usage in winter. Lots of short trips often see more energy used, again for heating the car up from cold.
The other factor with efficiency is that it really drops off with speed, i.e. 50, 60 and 70mph are quite different efficiencies.
samoht said:
There seem to be two possibilities:
a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm.
Is B really a possibility? We’ve had multiple power cuts in various houses with hardwired fire alarms, I’ve never had the fire alarms go off due to a power cut/tripped fuse.a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm.
If its A, than surely its when a fire is going to start properly, rather than if.
gangzoom said:
samoht said:
There seem to be two possibilities:
a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm.
Is B really a possibility? We’ve had multiple power cuts in various houses with hardwired fire alarms, I’ve never had the fire alarms go off due to a power cut/tripped fuse.a) something electrical got hot and emitted some smoke, causing the alarms to go off 'for real'
b) the transient effect when the car reached 100% and abruptly cut the 13A current caused electrical interference which tripped the fire alarms, causing a false alarm.
If its A, than surely its when a fire is going to start properly, rather than if.
If it was A, it would be a bit of a co-incidence that the car was fully charged when OP checked it right after the alarm went off. It would be a bit co-incidental for it to charge all the way to 100% and then start smoking, rather than sooner. Another data point is that OP couldn't smell any smoke when they woke up and checked.
The OP has presumably bought a cheap three-pin charger as a stop-gap until their hardwired 7kW charger can be installed, it could potentially be doing something strange at the cut-off point. Electricity is complicated and sometimes the change in current can itself cause a magnetic field and potentially voltage spike.
The fire alarms are electronic devices connected to the mains power supply, I'd think it would in general be possible for a supply fluctuation to flip them into an 'alarm' state in the absence of actual smoke.
I'm not sure, I'm not enough of an electrical engineer to rule the possibility out. At the same time the overload/smoke hypothesis certainly should be considered a very real possibility.
On the 13 amp point, remember that lots of the world have different electrical systems and these chargers are often generic with different plugs. They dont make physically different units for different countries - they typically just put different plugs on.
Plenty of places have 16amp sockets.
I wouldnt try to use anything over 10 on a uk socket.
Plenty of places have 16amp sockets.
I wouldnt try to use anything over 10 on a uk socket.
hi all,
Thanks for the feedback.
The device allows the user to set 6 / 8 / 10/ 13 amps before charge. The default is set to 13 amp. I will change that down to 10amp,
The device is plugged into the detached garage, the smoke alarms are in the house, i feel that even if the garage was smoking then the alarms wouldn't have gone off so I'm going to assume it was some weird feedback when reaching 100%
At the time, no plugs were warm, the supply boards all ok, no tell tale browning etc either.
Going forward, the next time i need to charge, it will be during the waking hours where i can monitor it fully at 10amps and see what happens.
Thanks for the feedback.
The device allows the user to set 6 / 8 / 10/ 13 amps before charge. The default is set to 13 amp. I will change that down to 10amp,
The device is plugged into the detached garage, the smoke alarms are in the house, i feel that even if the garage was smoking then the alarms wouldn't have gone off so I'm going to assume it was some weird feedback when reaching 100%
At the time, no plugs were warm, the supply boards all ok, no tell tale browning etc either.
Going forward, the next time i need to charge, it will be during the waking hours where i can monitor it fully at 10amps and see what happens.
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