Oh, I meant to say: one of the things I'm wondering about is how much faster a dedicated charging point would be. If it's only, say, twice as a fast then surely I might as well leave it charging all night anyway? I mean, I'm not going to unplug it at 2am!

 

Oh, I meant to say: one of the things I'm wondering about is how much faster a dedicated charging point would be. If it's only, say, twice as a fast then surely I might as well leave it charging all night anyway? I mean, I'm not going to unplug it at 2am!

I think someone needs to explain whether the Zoe has a program that permits you to tell it to charge to 80% an then stop or will it go to 100% if you leave it on overnight?

Or how common is it that 7kW chargers can be dialled down to 2 or 3kW?

 

I believe grannies are ~2kw, Home charging points are 7kw. so just over 3x faster. If you wanted to most home chargers can be crippled down to 3.6kw to reduce strain on your house (if you run immersion heaters overnight and have an undersized house fuse for example).

The main reason to get a proper charger is the fact they are safer.
Most sockets arent designed to have that level of constant current draw for hours upon hours. If the socket itself isnt brand new then that is also likely worn and can add to the heat worries.

Granny Cable Compatibility?

So I had my granny cable melt the socket it was plugged into - socket somehow still works but can’t check the status of the cable due to melted plastic around the prongs. I wanted to know if it would be safe to use the granny cable provided by Tesla (for the model Y) to charge my Zoë?

www.speakev.com

There are plenty of reports of Granny chargers melting into the socket they are connected to. These were originally supplied as "in case of emergencies" not "save £800 and use this instead" however buying EVs is like the wild west where sales people still say anything they can to get a sale..

Many people use them fine without issues for years, Similar numbers get smoke, scorching or excess heat. I decided not to use mine overnight because I couldn't hold my hand onto the back of the plug casing for longer than 20seconds due to the heat after 4 hours of charging (and that's in a brand newly installed external socket).

 

It would be about 3 times as fast at 7.2kW.

The biggest benefit, apart from the speed, is really one of safety. Granny leads are not designed for every day use and while you can do so it is not the safest. It can be done safely if you use a dedicated circuit which is installed properly taking into account earthing and the issues surrounding a potential earthing failure. But you can't get around it... granny leads are not the best or safest way to charge an EV.

So if you want to carry on using the granny for regular charging then that is your choice and you will find many people on the forum saying that it is perfectly safe and that they have never had a problem. It can be done safely but I would recommend that you follow the recommendations listed many times through this forum and don't just use any spare socket in the garage or house.

My recommendation - get a dedicated EVSE... you won't regret it

 

Do you have an overnight EV tariff? Mine has a four hour cheap window (7.5p/kWh on Octopus Go) and my car would never charge in that time on a granny charger, never mind the safety issues already mentioned.

 

Thanks. No, we're with Ecotricity (100% "green" I think?) and they are not the cheapest -- but the ethical option never is.

 

I used a granny charger for the first few months of EV ownership, whilst I didn't have any problems I was glad to get my charger installed.

 

It's slow, but I understand that's no bad thing from a battery point of view.

I believe that the latest Zoes still use the chameleon charger. Unlike conventional onboard chargers, they are very inefficient at low amps. So if the granny charger draws 10A, you may only be feeding 1.7kW into the battery (while paying for 2.4kW).

 

I used my granny EVSE for 6 weeks before I got a 7kW EVSE.
I am on IO so can get a full charge at 7.5p/kWh.
Like others have said it is far safer and 3x faster.

 

I believe that the latest Zoes still use the chameleon charger. Unlike conventional onboard chargers, they are very inefficient at low amps. So if the granny charger draws 10A, you may only be putting 1.7kW into the battery (while paying for 2.4kW).

My experience is you rarely get full speed. You're likely pulling/paying 10% less to start with. Then add the loss. It's good if you can measure the energy used somehow.

Still it's true that especially first Q-motor Zoes are very inefficient it's likely to do with the 43kW charger design that is very inefficient at low speeds. The Megane has newer charger design and a lot more efficient.

 

Hope the OP isn't using an extension cord along with the granny charger....

 

No way! 10m Masterplug reaches all the way from the socket at the back of the garage, under the door and out to the car easily.

 

• granny can be safe but make sure to check the cabling is ok. Check the plugs regularly to make sure they aren't geting too hot etc
• a mid-way option can be to get a dedicated circuit run and plug into that which gives you more secruity the circuit is ok. Something like a commando socket may be a step up but less cost than a full EVSE
• likely more efficient charging (so more going into the car vs being wasted with losses)
• EVSE will be around 3x faster as mentioned. That gives you options. If you have a time of use tariff that will be around 4 hours which means you may need the extra speed to be finished in time.
• a time of use tariff also means something like 3x less cost to charge vs standard rate.

the combination of the above means 3x faster charging, potentially 3x cheaper charging, potentially even more with more efficient charging. That speed also unlocks things like faster topups if you need it at short notice - so generally much more flexible.

If you don't have time of use, definitely look into it. Octopus are also committed to green energy and things like their intelligent octopus will control your charger to charge at the most green/low carbon times which may be of value to you too.

A smart meter will be needed but thats often free to install but can be a bit of a wait.

 

I’ve used mine twice when EVSE broke down, but that was during the day when I could keep an eye on it and check the plug and socket for heat.
mine is a Kia granny charger and can be set on 10-8-or 6 amps, depending on requirements.
All my electrics and cables etc are relatively new and are checked by the installer every year, including checking the tightness of cable connections in each socket with a torque screwdriver.
However, you have to consider if you did have a serious fire due to heat in the cable or socket and it caused serious damage to the property, what would your insurance company do when they discovered that you were using a charger that wasn’t designed for continuous use over a long period of time.

Of course 7Kwh installations can suffer from fires, mainly due to poor installation (I know because I’ve had a small fire in a CU installed by an EVSE supplier) or poor house wiring, but they are few and far between.
Personally I’d just use mine for emergencies, not as a full time charger, but that’s just me, you can off course decide for yourself

 

We got a Evios One home charger installed ahead of our EV arriving a couple weeks ago we opted for the surge protection too. My other half was too nervous to use a granny charger, especially overnight. You may never have an issue but there is a risk.

 

I charged on an outdoor socket using a Hyundai 3pin EVSE when on Holiday with it limited to 6A and the socket still got warm (They usually run at 10A, I'd specifically bought the Hyundai one and carry it instead of the MG one because you can reduce it).

 

I set mine at 8A and only slightly warm.
6A takes to long

 

I set mine at 8A and only slightly warm.
6A takes to long

Indeed but as I had no idea on the state of the wiring I didn't want to risk anything higher.

 

I have been using granny charging for years at home. What I did was get a professional electrician to come over and install a new socket and explained everything to him and he said it would be OK.

Since the maximum I would ever do would be 1,600W for 12 hours I told him I needed him to guarantee the socket would handle at least 2,000W for 20 hours straight.

To begin with, I only charged 2 or 3 hours at a time and then stopped it and checked for heat on the prongs and the socket. It was always cold.

To begin with, I didn´t risk leaving it on overnight, then I did overnight charging a couple of times a year when necessary. Due to increased mileage, I now need to do 1-2 overnight charges per week.

I tend to charge on the lowest setting of 6 amps which is about 1,100 watts. There is a higher setting of 8 amps (1,600) which I almost never use for overnight charging.

I very rarely have let it charge for more than 10 hours. If it has been charging for 10 hours, I check it´s still cold on plug and socket (it always is) and unplug it for a few hours before plugging back in again if needed.

I think some people have chargers that allow you to charge at 12 amps or 16 amps. I wouldn´t do that. My guess is that higher amp charging is more likely to produce a problem.

I did have an issue that the heavy part of the charger was dragging its weight on the socket and caused the socket to come out of the wall a little. That was fixed, but I try to avoid this by balancing the charger on something so it isn´t dragging any weight on the socket.

I suggest you have a professional electrician visit your house and give an opinion.

If I owned my house instead of renting or had access to overnight rates, I´d probably have got the charger though.

 

if you're going to get a dedicated circuit, is it better to get a commando socket? if you get eg a 32A circuit wired in to the consumer unit that'd be the same, but I assume the commando socket is more robust for continuous load than a regular 3 pin plug/socket? There must be a reason it gets recommended.

 

Another vote for not overnight. I've used mine for up to around 4 hours to take advantage of surplus solar when the sky has been cloudless, so not very often for that long then! I'm able to periodically check the plug and have never had an issue (even at 10A) even during longer charges. I had a commando plug put in and use an OHME: the biggest issue being the earthing. As I also block paved an area of my terrace house garden as part of going EV the additional expense was put in the 'house maintenance' budget, and if that is a consideration for you in the future it should help the house sell.

Edit to answer Mrklaw; mine is on a separate circuit as during a meter change the DNO put in an isolating switch which enabled work on the system without breaking the seals.

 

6yrs of ampera ownership, and two charges a day on the granny charger... so ymmv...

 

To try and get a sense of the risk level I once emailed someone who drove an electric car between the Netherlands and Australia and he said he burned 5 sockets in hundreds of charges.

 

I have seen a couple since I got my first EV back in 2010. One completely and totally melted the plug to point where the plug was unrecognisable.

Never had anything happen to me personally though but I am particularly careful where and how I charge with the granny charger.

 

A lot probably depends on circumstances. We have an old, detached house and a garage and don’t plan to move. So investing in a home charge point was justified on the grounds of convenience and safety. Having an EVSE may even help a little when it comes to selling. Even though the cost was more like £2K due to the distance and complexity of hiding the cabling under the floors, I think it was still worth it and proportionate to the cost of the EV itself and the property. But if I was renting, or thought I’d be moving in the near future, or the charger was outdoors and hard to install etc. then it’d be a more difficult decision.

For the OP I’d say that a few weeks in the summer may not be representative of a longer period of use, especially in the winter, and especially if the EV is their only vehicle. They need to consider how often they will need it to be charged up quickly at short notice across a typical year of usage at least.

We are retired, but even in just three months there have been occasions where it would have been inconvenient and expensive not to have been able to charge up to 80% overnight in the 7.5p/kWh slot. Usually these have been where we had consciously run the car down to 15-20% and then plans changed and we needed it for an unscheduled longer journey next day.

 

I might be biased because I have a business advising on, and installing, EV chargers, but....
as others have said - safer, because you're getting a unit designed and installed so it can happily deliver 7kw charging for several hours without getting hot (and would be 6-7 hours overnight if your Zoe came home nearly empty)
as others have said, could let you exploit cheaper time of day tariffs
another point not, I think, mentioned yet is that all new chargers nowadays are "smart" and typically app controlled. By default they are also set up not to charge the car when the grid is stressed (early evening) with the aim you'll instead charge overnight, when (at least on windy nights) the grid is awash with excess green electricity

 

So far I've been charging it overnight on a granny cable, which works fine. It's slow, but I understand that's no bad thing from a battery point of view.

The battery doesn't care whether it's charging at 2kW or 7kW. The argument about battery life only applies to rapid DC charging at the car's maximum charge power.

 

Hello All

I've had my Renault Zoe for a few weeks now and am loving it.

So far I've been charging it overnight on a granny cable, which works fine. It's slow, but I understand that's no bad thing from a battery point of view.

However I am thinking of getting a home charging point.

My wife says it's unnecessary, especially as by the time we unplug the car for work in the morning it's usually or around the magic 80%.

So what are the pros and cons, apart from the cost? (I have the money put aside for the charging point and don't mind spending it so that's not an issue.)

Thanks

Ollie

For me it's the way I get access to Intelligent Octopus, for which you need either an approved charger or make of car with the ability to access car remotely and schedule charges. I've worked out that with my Ohme Home Pro charger that I will be able to pay for that by the savings I make with the car charging and the cheaper home use (by scheduling washing machines, Dishwashers during the cheap window 2330 to 0530 at 7.5p within the year. The great thing with intelligent is that if you plug in earlier and they have surplus electricity they may switch your charging on earlier bringing the whole house to that cheap rate as well.

 

How do you program your washing machine to come on when Octopus turn on cheaper electricity before your machine program is due to start? How do you know, do you have to change timer settings?
We set 2 big steam ovens and washing machine on timers for the Octopus Go 00-30 to 04-30am, but they are set on inbuilt timers and come on around 3am when we’re in bed. 😜

 

If you're using your granny charger as your 1 and only, you have no backup if & when it fails. These can & do wear out over time. And when they fail, there's a chance of a catastrophic failure with 240V arcing over down the 12V control wire and into your car, risking damage to the car's charge controller. Read my experience here!

You're far safer in every way if you get a robust EVSE as the main charge device, and keep the granny for occasional/holiday/emergency use.
Granny EVSE finally dies - beyond even my zombie efforts...