Why buy a wall Connector ?

[Nogasnorman]

I have ordered a Tesla for delivery in January and am wondering how to charge it when at home. Tesla tell me that most of their customers buy the Tesla Wall Connector for £438 and according to Home charging installation that will charge at a rate of 7.4 kW or 22 mph.

But the car comes with a 6 metre Tesla Mobile Connector cable and when used with a blue connector that can also charge at a rate of 7.4 kW or 22 mph.

So what's the advantage of a wall connector (Tesla or other) ? Why not just get a blue industrial socket to hook up with my single phase supply and save me £400 ?

 

[outOfPhase]

I am in the same position as you: in the UK, car ordered and wondering what to do. However I've considered a 3rd option too, which is to use a 7kw PodPoint. As far as I can work out (and I'm learning so may be wrong) the pros-cons are:

• industrial connector is intended for use inside, so OK in a garage but not on exterior wall, plus you need to keep unplugging the MC to take with you
• PodPoint has a government grant that covers about half the cost - it's about £500 installed, while the Tesla charger with installation likely to be twice that
• Telsa charger 'look and feel' is better - it has the button to open the charge port and the style is consistent with the car.

On balance I'm inclined to go for the Tesla wall charger, but it will cost an extra £400-500. Though to be fair to PodPoint, theirs is more stylish than some of the others wall units.

 

[Nogasnorman]

PodPoint seems to charge at up to 7 kW cf. 7.5 kW for the Tesla alternatives. They seem to cost £485 fully installed (after the OLEV grant which Tesla wall unit does not entitle you to as it is tethered) cf. £438 + filling.
Not much to choose between them really.
But I still don't see either providing anything that the supplied mobile connector does not, so what have I missed ?

 

[outOfPhase]

But I still don't see either providing anything that the supplied mobile connector does not, so what have I missed ?

Will the outlet be outside or in a garage? If outside then the MC will get wet and dirty (with likelihood of the odd slug too) do you want to unplug that and put it in your boot before every longish trip?

Technically though I agree they serve the same purpose and provide the same 7.4 kW on a single phase supply.

 

[Nogasnorman]

Yes, the minor inconvenience of unplugging both ends rather than one seems to be the only difference. For me, I have a car port which gives good protection from rain. Any slugs are just the cook's bonus.

 

[jerry33]

1. The wall connector has a longer cable (not much longer, but in some cases that extra length might be needed).
2. One less connection. Problems tend to occur at the connection points, so the fewer the better.
3. Cable is thicker--cooler running, less resistance.

That said, I just use the UMC. The six to eight times I unplug it per year aren't really an inconvenience. I do have a holder for the "box" part to reduce the stress on the plug and cable. Although the initial cable was replaced, the current cable has been working fine for three years.

I have had ants, but no slugs.

 

[Brain1000]

You may wish to have a look at the Rolec charge point - type 2 socket at £149 including installation after grant. A cable will be needed but it could be used on the road. It was recommended by a guy I met at a Tesla 360 meeting. I'm looking at using it myself.

Grant Funded Home Charging Points | EV Charging | Rolecserv

 

[Gig103]

Another reason to get the Wall Connector is if you have Dual Chargers. I don't know what plug the UMC comes with in the UK but here it's a NEMA 14-50, which means the Tesla charges at 40A maximum. With dual chargers you need the wall connector in order to put 80A into the car.

 

[Hugh Mannity]

It's convenient to keep the UMC in the car so it's always available if you need it on the road.

 

[bob_p]

The HPWC is more convenient, with a longer cable, can provide faster charging, and allows the UMC to stay in the car.

The primary reason NOT to get the HPWC is cost. Faster charging usually isn't needed, so the HPWC is primarily a convenience purchase - and you'll need to evaluate if the additional cost of purchasing the HPWC and connecting it to power is worth the benefits.

We have one Model S today - with an HPWC. We are likely to get a second Tesla in the next few months - and for the 2nd car, we may go with only a 14-50 plug and use one of the UMCs for charging the 2nd car.

 

[Nogasnorman]

I believe that faster charging requires 3 phase electrical supply which hardly any domestic houses have (in UK at least). The frequent un/plugging of the single mobile connector will weaken it over time and having a second power source for the time it fails would be useful. Plus, would save having to unplug both ends at the end of a charge.

So I'm thinking of buying a Rolec Charge Point which is 40% of the cost of the Tesla wall charger and appears to do the same thing.

 

[jerry33]

I believe that faster charging requires 3 phase electrical supply which hardly any domestic houses have (in UK at least). The frequent un/plugging of the single mobile connector will weaken it over time and having a second power source for the time it fails would be useful. Plus, would save having to unplug both ends at the end of a charge.

So I'm thinking of buying a Rolec Charge Point which is 40% of the cost of the Tesla wall charger and appears to do the same thing.

The UMC gets unplugged a maximum of eight times per year for me. Even the cheapest 14-50 connector has a duty cycle of around 300, making it good for over twenty years. The receptacle's connections should be inspected for connection tightness every few years or when the temperature seems higher than normal. So while there is one less connection with the HPWC, the practical difference is minimal.

In North America both the UMC and HPWC run on single phase (though the HPWC can also run on 3 phase, although it generally charges slower on 3 phase because 3 phase is 208 V vs 240 V for single phase). The difference is to get the full rate for the HPWC a 100 amp circuit is required vs. 50 for the UMC. Many older homes can't handle a new 100 amp circuit without changing out the electrical panel, and in the worse case the utility side service, so the 50 amp UMC becomes much less expensive.

 

[Nogasnorman]

Thanks jerry33 but that throws up another question. According to the .PDF that contains installation instructions for the wall connector, it can output varying power levels: 80A, 72A, 64A, 56A, 48A, 40A, 36A, 32A, 28A, 24A, 20A, 16A, 12A. And I have been assuming that if you connect an empty battery it will start pushing 80 amps out then gradually reduce the power outage until the battery is full.

The spec for the mobile cable stated that the socket can handle 32 amps which is matched by the Rolec Charge Point. So I'm now thinking that the 80A, 72A, 64A, 56A, 48A, 40A, 36A outputs from the Tesla wall connector must be available only if three phase power is supplied.

I know that the maximum rating of domestic supplies in the UK is 100 amp theoretical, probably more like 80 amps in practice. So if we supply 80 amps in on a single phase supply, does that mean we can expect almost 80 amps out ? It seems not as Home charging installation lists 11 kW as the maxximum (assuming you don't have the high power charger upgrade (which only works on 3 phase)).

But 11 is greater than 7.5 so perhaps the wall charger can deliver more than the mobile cable. If so, why should that be ?

 

[jerry33]

Thanks jerry33 but that throws up another question. According to the .PDF that contains installation instructions for the wall connector, it can output varying power levels: 80A, 72A, 64A, 56A, 48A, 40A, 36A, 32A, 28A, 24A, 20A, 16A, 12A. And I have been assuming that if you connect an empty battery it will start pushing 80 amps out then gradually reduce the power outage until the battery is full.

Compared to a Supercharger, 80 amps is peanuts, so you won't see any reduction until the very end. This happens with the UMC too.
The various output levels are selectable when installing the HPWC so that you can install it regardless of your electric service--although you don't get the maximum speed unless you set it to the maximum output.

The spec for the mobile cable stated that the socket can handle 32 amps which is matched by the Rolec Charge Point. So I'm now thinking that the 80A, 72A, 64A, 56A, 48A, 40A, 36A outputs from the Tesla wall connector must be available only if three phase power is supplied.

I don't know about the U.K. but that's not correct for North America. 3 phase power isn't for residential use here--to run 3 phase to a residence would have astronomical costs--so it's all 240V single phase. Also to use the other EVSE, you'll have to use your J1772 adapter every time. This is a kind of pain because you have to open the charge port from the display rather than just walking up to the car with a Tesla cable. I'd also purchase a second adapter, if you go that route, so that you can keep one in the car.

I know that the maximum rating of domestic supplies in the UK is 100 amp theoretical, probably more like 80 amps in practice. So if we supply 80 amps in on a single phase supply, does that mean we can expect almost 80 amps out ?

No. EV charging is a continual load so code requires that the maximum is 80% of the circuit capacity. This means a 100 amp circuit can charge at 80 amps. (Exception: there are very rare and expensive breakers that can take a continual load at the breaker capacity, and assuming the wiring is up to it--this isn't the normal set up though.) If the service into your house is only 100 amps, you won't be able to get anywhere near 80 amps because of loads to the rest of the house. Most houses in North America that have the HPWC set to 80 amps have a 400 amp or larger service. I have a 200 amp service and it works fine with the UMC. (I also have a Clipper Creek 32 amp EVSE to charge the Leaf). Most of the time I can run both at the same time, but once in a while it auto-reduces the amps. I have them set so there is normally very little overlap because the Leaf typically leaves later than the Model S.

But 11 is greater than 7.5 so perhaps the wall charger can deliver more than the mobile cable. If so, why should that be ?

By code, the UMC requires a 50 amp circuit and will output 40 amps to the car. The heavier wiring of the HPWC will reduce the resistance of the wire at any given output compared to the UMC. How sensitive your measuring device needs to be to measure this difference is another question.

 

[outOfPhase]

So I'm thinking of buying a Rolec Charge Point which is 40% of the cost of the Tesla wall charger and appears to do the same thing.

Please update us on how this goes. The Rolec unit is tempting as it appears significantly cheaper than an installed Tesla wall charger, although it seems odd that their website quotes the same "from" price for both 16A and 32A versions. I expected a premium on the 32A, if only for the higher spec of cable run to the unit.

 

[miimura]

There is a mix of EU/UK and North American content in this thread. Since the OP is in the UK, I will try to summarize the charging capabilities provided by Tesla in that market.

Mobile Connector: Max 11kW. Blue Socket adapter (Single Phase 32A, 7.4kW) or Red Socket adapter (3-phase 16A, 11kW)
Single Phase Wall Connector: various settings up to 40 amps max (9.2kW)
Three Phase Wall Connector: various settings up to 32 amps max (22kW), this unit may also be used with single phase supply 32 amps max (7.4kW).

It looks like the older Single Phase Wall Connector may not be available any more. In that case, you cannot charge with more than 7.4kW power from single phase. Also, breakers are commonly rated for continuous use in Europe, so the 80%/125% rule that people talk about for North America does not apply. The Wall Connector manual indicates you should choose breakers rated for continuous use and set the rotary switch to the same amperage value.

So, if your UK home has only single phase supply, the Rolec and the Tesla Wall Connector will have the same capability. The Rolec will be cheaper, but you must agree to let them collect your charging data from the unit to get the subsidy.

I should also mention that the car's capability also comes into play above 11kW. Older cars that have dual chargers can take the full 22kW, but I think the facelift S and Model X have a single charger that is either 16A 3-ph or 24A 3-phase max. So, the maximum AC charging rate is 16.5kW on those newer cars.

 

[Brain1000]

So, if your UK home has only single phase supply, the Rolec and the Tesla Wall Connector will have the same capability. The Rolec will be cheaper, but you must agree to let them collect your charging data from the unit to get the subsidy.

I understand that the OLEV grant for the Rolec unit no longer requires any data collection.

 

[miimura]

I understand that the OLEV grant for the Rolec unit no longer requires any data collection.

That's great. It would not be a big deal to me, but some people get their knickers in a twist about that stuff.

 

[NullException]

In the UK, the most the HPWC will supply on single phase is 7.4kW (32A at 240V). This is the same as you'll get from using the UMC with a single phase commando socket.

It really is a matter of convenience, unless you have a 3-phase supply.

Please see Home charging installation

A Tesla Wall Connector enables charging up to 22 kW. The achievable charge rate depends on your grid connection and vehicle configuration.

• The majority of homes have a 1-phase grid connection, allowing you to charge up to 7.4 kW or 22 miles/hour*. This is more than sufficient for overnight charging.
• Some homes have a 3-phase grid connection. This connection enables you to charge up to 11 kW or 34 miles/hour*.
• If more power is available or if you plan to upgrade your grid connection, a Tesla can charge up to 16.5 kW or 51 miles/hour*. To achieve this charge rate, the car needs to be equipped with the High power charger upgrade

 

[jelloslug]

The UMC gets unplugged a maximum of eight times per year for me. Even the cheapest 14-50 connector has a duty cycle of around 300, making it good for over twenty years. The receptacle's connections should be inspected for connection tightness every few years or when the temperature seems higher than normal. So while there is one less connection with the HPWC, the practical difference is minimal.

In North America both the UMC and HPWC run on single phase (though the HPWC can also run on 3 phase, although it generally charges slower on 3 phase because 3 phase is 208 V vs 240 V for single phase). The difference is to get the full rate for the HPWC a 100 amp circuit is required vs. 50 for the UMC. Many older homes can't handle a new 100 amp circuit without changing out the electrical panel, and in the worse case the utility side service, so the 50 amp UMC becomes much less expensive.

Don't forget that to take full advantage of the HPWC you will have to upgrade the car to either the 80 amp dual charger or the 72 amp charger (depending on the vintage).