Question for sparkies?

smitchy73

I'm thinking of getting an electric vehicle later this year, and of course I need to think of getting a charging point at home. I'm all for getting a wall point installed, but would like to know what really is the difference between getting one of those, compared to having a commando all weather box installed instead.

Just looking for an opinion on it from someone preferably outside of the motoring industry who I'm assuming will benefit from the promotion of a tie in with the likes of British Gas/EDF etc etc.

Many thanks.

Jaynne

Not a sparkle but leccy cars can usually charge off regular sockets and higher power sockets. The higher power sockets charge faster and have a different type of plug. What type of socket are the car companies selling you?

jc808

would it be cheaper to do it on economy 7?

Jaynne

jc808 wrote: »

would it be cheaper to do it on economy 7?

You have to use a certain percentage of your power in the cheap period for economy 7, google it but I thought it was something like 20%.

If you're unsure you can get cheap leccy meters that measure your household consumption. My guess is that in the absence of electric storage heating just an electric car is not enough to warrant economy 7 but it depends entirely on your house and its appliances (which ones can be timed to run in the cheap period for instance).

smitchy73

Jaynne wrote: »

Not a sparkle but leccy cars can usually charge off regular sockets and higher power sockets. The higher power sockets charge faster and have a different type of plug. What type of socket are the car companies selling you?

Yeah you're right EV's can run off a normal socket, but I know the car I plan to get, the Renault Zoe, has the ability to use a trickle feed from a normal domestic supply, or an accelerated charge from an increased supply, as well as a fast charger, the normal boxes charge about 16kw, accelerated is double that, but I think it depends on how much is going through the trip hence why they suggest having a seperate feed, but i'm sure this could come from an outside 'commando' socket if set up properly.

smitchy73

jc808 wrote: »

would it be cheaper to do it on economy 7?

Really the only things that would be on overnight when the car is charging would be the car and the fridge, everything else is switched off, oh except mobile chargers are usually going!
I've seen some quotes of it only costing say £1.50 to charge overnight on Economy 7, but as someone else said a percentage of your usage has to be during the period, but some of the other electricity suppliers are giving special rates for EV charging if done between 8pm and 7am which is pretty much when i'd do my charging.

Jaynne

smitchy73 wrote: »

Yeah you're right EV's can run off a normal socket, but I know the car I plan to get, the Renault Zoe, has the ability to use a trickle feed from a normal domestic supply, or an accelerated charge from an increased supply, as well as a fast charger, the normal boxes charge about 16kw, accelerated is double that, but I think it depends on how much is going through the trip hence why they suggest having a seperate feed, but i'm sure this could come from an outside 'commando' socket if set up properly.

I've had a quick look at the Zoe homepage which says that a quick charge is done in 30 minutes. To get 16kW in that time you need a supply of at least 140 amps which if I'm not mistaken is bigger than the regular fuse coming in from your leccy company hence their hooking up with them to give you a dedicated supply.

I don't see how you could do that on a normal supply. The regular 6 hour charge could of course be done from a normal outdoor socket.

Jaynne

I've also just seen that there is a mid point of "accelerated" charging which can be done in an hour. It might be that this could be done off a 60A fuse (Renault could tell you this). At this point my sparky knowledge breaks down - I don't know if you get 60A fuses for domestic supplies. You will presumably need a special socket to plug the car into to take advantage of this and obviously a huge amount depends on your houses wiring.

DVardysShadow

Jaynne wrote: »

I've had a quick look at the Zoe homepage which says that a quick charge is done in 30 minutes. To get 16kW in that time you need a supply of at least 140 amps which if I'm not mistaken is bigger than the regular fuse coming in from your leccy company hence their hooking up with them to give you a dedicated supply.

I don't see how you could do that on a normal supply. The regular 6 hour charge could of course be done from a normal outdoor socket.

Let's clarify the difference between kW [kiloWatts] and kWh [kiloWatt hours].

kW is the rate at which energy is delivered and 16kW is equivalent to a current of 16,000/230 = 70Amps. This is within the capabilities of a domestic supply with a 100A fuse - but will need its own dedicated fuse unit. A normal consumer unit will not handle this.[edit: D'oh. A 70A fuse will not discriminate adequately with a 100Amp main fuse. Preferably, you should be using no more than a 50A fuse or a 63A fuse at a pinch after a thorough assessment of fuse characteristics.]

kWh on the other hand is the amount of energy. Now, in one hour, a 16kW supply as described will deliver 16kWh. If you want to supply 16kWh in 30 minutes, this requires a 32kW supply, which as you point out is 140A and beyond the capability of a normal domestic supply.

Jaynne

DVardysShadow sounds like you agree with me, my background is some uni electronics and physics but not much in the way of household fuses. Lets just say I didn't ever have to stick a k infront of the W with the sort of circuits I was interested in.

smitchy73

Thank you Dvardy and jaynne, I would've wanted a seperate supply to the power point, but wasn't sure how possible this was within the realms of the feed into the house, I know my current fuse board says max of 80 amps, so if I was feeding a large amount to the car charging then I wouldn't really be able to power anything else in the house and the last thing I would need during the night is for it to trip and not charge and the freezer defrosts etc.
It's just as a thrifty type of person just looking to find out if it was possible to have the feed and work out to be a lot cheaper than the £800 currently being offered by the likes of BG/EDF.
You have both given me great answers thanks again.