Home Charging

[Golfdriver]

Hi Folks,

I've recently placed an order for a Model S 75D. As a result, I'm looking at my charging options, an electrician has offered 2 options on the info I have given him.

Option 1 Use My existing consumer unit which is set at 20A and then set the Tesla wall charger at 20A rather than 32A. This option seems pretty simple however I have asked what the effect will be on the charge rate.

Option 2 is to install a new consumer unit which will look untidy due to the configuration of my current set up and I'm sure my other half will not be impressed. This can then charge at 32A.

Another thought I have is that I live a minutes drive from 8 superchargers so I could use them when required, it really would be easy in terms of popping around for 20 minutes or so. Most days I will not drive more than 50 Miles and my car will be on the drive most nights for 10 hours plus so I could simply charge directly from a 3 pin plug.

As a Tesla novice, I would love any thoughts or opinions on what my best options are.

Thanks

Golfdriver

 

[WannabeOwner]

I've recently placed an order

Hopefully you got a referral code from somewhere?

Charging speed approx:

32 Amps = 22 MPH
20 Amps = 14 MPH
Regular 13 Amp socket typically 5 - 7 MPH

I usually find that 13 AMP (e.g. when charging staying at friends house for the weekend) is less efficient, so over-all more wastage, so personally I would want to avoid that long-term.

I'm no electrician,but someone recently suggested just T-ing off the supply to, in effect, create a dedicated supply to the charger. I don't know if that would be the "big ugly consumer unit" that you allude to?

... the whole nation will have to grapple with these types of dilemma as the infrastructure for car charging is rolled out ...

I live a minutes drive from 8 superchargers

Is it a minute's walk? If not I doubt you will want to be sitting (often) in the car whilst charging.

Frequent Supercharging stresses the battery and will, after a set number of such charges, reduce the speed at which Supercharging then occurs, so not the best option, long term.

My 2p worth:

Even if rarely used, its nice to have the fastest charging you can 'coz sure as eggs-is-eggs you'll need it one day. Nearby Supercharger is an alternative in your case

I would also want the infrastructure to support a 2nd EV in a few years time, or to charge a visiting EV. (Assuming you have enough off-road parking).

I would only want a tethered charger for my regular home-charging. "Tethered" means that the charging unit has its own cable attached, and you just plug that into the car. The alternative is to have a plain socket on the house (Blue Commando socket, or even just a 13 Amp socket), and then use the "UMC Cable", which comes with the car, to plug in. Reason I don't like this (for frequent use) is it means coiling up the cable and stowing it in the car (wet / whatever) after every use, which is hassle. The joy of home charging is Arrive: Hop out; Plug in; Done. Leave: Un-Plug, hang cable over charger; Hop in; Drive off with a full tank

Wear and Tear on the UMC is not good news. That would leave you without a backup, and the UMC itself is expensive ...

The Tesla charging unit looks nice and is well engineered - e.g. it supports load-balancing when you have bought your second Tesla and they are both charging But there are alternative brands with various features including, for example, adjusting the charge rate to maximise use (and minimise Export) of power from any Solar Panels that you may have.

There are also units available with OLEV grant, but a frequent experience is that either the extra paperwork for the grant, or just "greed-economics", means that the OLEV price is higher, and as such doesn't work out a great deal cheaper, and the OLEV fitters seem to have favoured brands that have not been especially reliable, nor beautiful!

"GolfDriver" - is that Sooner To Be Ex-Golf driver (no love lost between me and VW ...), or the type where you hit balls around the countryside?

 

[PatrickCH4313]

Just a question: in the U.K. don't you have the connection type of a 3 phase 230/400 VAC and 16 A (what we used in the past for washing and drying machines). Since these new machines use the 220 V / single phase, I was able to use this type of connection supporting faster charging (66 km/h or 41 MPH) using the TESLA Mobile Connector and the TESLA 5-pin IEC 60309 adapter (red).

 

[Golfdriver]

Hi Wannabe,

Thanks for the response.

Thankfully I do have a referral code and it has been applied to my order.

I think I'm going to go with a Tethered 20A solution, that will meet my needs 80% of the time and on the odd occasion, I can use the supercharger on my doorstep.

I really appreciate your insight and help, very useful, I'm trying to learn as much as possible about owning a Tesla but help like this is priceless.

I will be an ex Audi driver in a few months, looking at the boot space in the model S my clubs will fit in with ease.

Thanks once again.

Golfdriver

 

[Golfdriver]

Just a question: in the U.K. don't you have the connection type of a 3 phase 230/400 VAC and 16 A (what we used in the past for washing and drying machines). Since these new machines use the 220 V / single phase, I was able to used this type of connection supporting faster charging (66 km/h or 41 MPH) using the TESLA Mobile Connector and the TESLA 5-pin IEC 60309 adapter (red).

Hi Patrick,

Thanks for your response I really have no idea, I'm leaving it all to the electrician.

Golfdriver

 

[WannabeOwner]

in the U.K. don't you have the connection type of a 3 phase 230/400 VAC and 16 A

Domestic we rarely have 3-Phase in UK, but we have 230V as standard (13AMP) throughout the house, so don't need special sockets for driers etc.. In some other countries in EU domestic 3-Phase is more common, and in that instance the single-phase voltage (e.g. around the house) is also 230V, so 3-Phase "sockets" will be 400V. Can't remember offhand, I'm sure there are others, but in the main its only USA that I can think of that is 120V around the house, with the consequential slow hair driers, and slow laptop chargers

I'm trying to learn as much as possible about owning a Tesla

Plenty of helpful people here might be worth a browse through recent topics in the UK forum, the same questions come up of course - although the information moves on with time.

• Insurance cost / providers
• Buy / Lease ... company car 100% first year write-off pros/cons
• Residual value
• Range-anxiety / trip planning
• Trim choices

 

[DJP31]

Given you mileage profile and the proximity of the Supercharger I think you’d be ok with the 20A tethered option, and would echo @WannabeOwner’s advice - get the Tesla wall charger. Using a 13 amp plug is last resort stuff and not ideal at home unless it’s the only option.

I note you do about 50 miles a day, I’m afraid that’s going to change , so when getting your insurance quotes double the estimated mileage.

As far as the golf clubs are concerned, absolutely no problem, for me that’s also including an electric trolley, shoes and battery.

 

[WannabeOwner]

... and battery

How ironic!

 

[arg]

Option 1 Use My existing consumer unit which is set at 20A and then set the Tesla wall charger at 20A rather than 32A. This option seems pretty simple however I have asked what the effect will be on the charge rate.

Option 2 is to install a new consumer unit which will look untidy due to the configuration of my current set up and I'm sure my other half will not be impressed. This can then charge at 32A.

If option 2 is really unattainable, option 1 will do fine for your regular driving, giving you a slightly higher chance of needing to stop at the local Supercharger if you have back-to-back long driving days. It will also make it harder to take advantage of Economy 7 rates; the cash saving isn't huge so this isn't a reason to jump through hoops to get 32A, but there's also a green aspect of it being preferable to charge at deep off-peak times to get power from the least polluting generation sources.

Avoid the 13A socket - it's slow (only 10A despite the "13A" name on the plug!), inefficient (as a rule-of-thumb about 1A gets used to run the computers/cooling systems/etc, so the slower you go the bigger percentage of your total gets wasted), and liable to wear out. Also, it's not ideal plan to use your UMC for daily charging, since you either have to roll it up every morning before you drive off (tedious), or you take it 'only when needed' and then find you forget and cause yourself huge inconvenience. Also, UMC as daily charging means you've no fall-back if it ever fails/gets damaged - whereas if your wall connector breaks you've got the UMC+13A to fall back on.

I'm a bit suspicious about the option1/option2; it seems odd that the existing consumer unit can only take another 20A. If it's really because the existing CU is old and limited, then replacing it with one that can may be a sensible option3. And even taking that at face value, usually when an extra CU is added just for the chargepoint it would often be added next to the meter rather than next to the existing CU. Maybe there's something unusual about your house that makes this 2nd CU difficult to site - normally they'd be tucked away somewhere out of mind. Hard to comment meaningfully without more info about your current setup.

 

[sidmini]

You will be fine with option 1, just remember to lug in every night and also if you benefit from e7 rates then makes sure the car knows to only start charging at that time to save £

 

[Beady3647]

On the subject of Supercharger use, I've had my 65 plate P85D for about 18 months averaging about 1200 miles a month. I had a 'Tesla Wall Connector 32A' installed at home and have probably used it around 10 times. I live around 15 miles from the Superchargers at Hopwood (M42) and have used them on a weekly basis. I used them last night and added 190 miles in around 65 minutes. In my naivety I started by charging to maximum and the last 15 miles would take anything up to an hour. I now set the limit to 225 (my maximum is 244) and pop to have a Costa (or similar). Admittedly I am retired and have more time to spare, I'm also frugal (my family say I'm mean!!!) and estimate my 20K miles so far have cost me £70ish in electricity charges.

In short, my own experience is that my charging rate has remained pretty constant regardless of the frequency of use. The lowest mileage at arrival I can recall was 6 miles (a bit scary) but it's normally between 30 and 50 and at a time that suits me best.

I would suggest, due to your proximity, that you use the (free) supercharger as often as is convenient but set the maximum charge at around 90% which will save time.

Of course your maximum battery/mileage will be higher than mine, being a newer model, which may impact on time taken to charge to 90%

 

[arg]

I live around 15 miles from the Superchargers at Hopwood (M42) and have used them on a weekly basis. I used them last night and added 190 miles in around 65 minutes. In my naivety I started by charging to maximum and the last 15 miles would take anything up to an hour. I now set the limit to 225 (my maximum is 244) and pop to have a Costa (or similar).

But is this actually a sensible thing to do? If you take on board 60kWh, that's only about £4 worth if you had bought it at home on E7 rates, and most of that saving is eaten up by your Costa coffee, and a little more by the extra miles you drove to get there (which also cost you in tyres, depreciaton etc as well as the charge wasted). So unless you actually enjoy hanging out at motorway service stations, it's a lot of bother for almost no financial benefit to you.

 

[Beady3647]

But is this actually a sensible thing to do? If you take on board 60kWh, that's only about £4 worth if you had bought it at home on E7 rates, and most of that saving is eaten up by your Costa coffee, and a little more by the extra miles you drove to get there (which also cost you in tyres, depreciaton etc as well as the charge wasted). So unless you actually enjoy hanging out at motorway service stations, it's a lot of bother for almost no financial benefit to you.

Totally see your points arg.

Maybe I should have been a bit more informative as I have relatives within 5 miles of the SC so I regularly (75%) of the time visit them at the same time. I don't have E7 (must look into that). I'm guessing that it has involved an extra 5-600 miles over the 18 months and saved about c£450.

The Costa comment was a little tongue in cheek as (my family are right) I'm too mean. But I can make use of the loos, have a chat with fellow owners, get approached by people wanting information (and in some cases clearly envious of my good fortune), catch up on my emails (don't do Facebook etc) and listen to what I want on the radio for a change!

 

[WannabeOwner]

my own experience is that my charging rate has remained pretty constant regardless of the frequency of use ... 20K miles so far

20k miles definitely not a problem with regular Supercharging Even my occasional-use must be around 3,000 Supercharged-miles p.a.

Bjorn has videos (he does a lot of miles - I'm guessing but 60K per year perhaps? - and Supercharging) showing his Supercharging performance slow-down, including (improving again) after he had a battery pack replaced under warranty.

Everyone's time "value" is up to them of course but Supercharging tapers after about 60%, and assuming that you don't reach the Supercharger lower than 10% that means some hanging about to get more than 70% at "full-ish speed"

I get:

<10% may be slow, particularly if the battery is cold (Charge on arrival, not the following morning after a hard frost!)

10% - 60% = 5 mins per 10%

60% - 70% 7m
70% - 80% 9m
80% - 85% 6m
85% - 90% 7m
90% - 95% 12m
95% - 100% 28m - then a further 24m to balance the cells (which will be variable "depending on ...")

I think that the maths of Supercharging to complete a journey work a whole lot better than charging to continue a journey. Typically on out-and-back journeys I make, that exceed 100% range, I start with a home-charge to 100% (220 real-world miles in my case) and thus 30 minutes at Supercharger at "optimum" (10%-60%) will get me another 50% / 110 miles. Its very rare that I do more than 300 miles in a day, but two or three times a month I do exceed battery-range.

If you start out at 90%, or less, you lose the benefit of the 100% home charge before you start, and increase the possibility of needing outward bound charge - which means leaving earlier to arrive on time of course. Personally I'd be hopeless at that!

Another possible benefit is the "contingency" home-charge to 100%; I always charge to 100% if my journey distance is 160+ miles - handy for bad weather or a Detour/Errand-request I have a regular journey that is pretty much exactly 160 miles and on one occasion I was late leaving and hoofed it on the way there, arrived spot on 50% but not concerned about the return journey as no rush .. but arrived home with only 2% even driving at 65 because of torrential rain on my return

 

[Golfdriver]

Thanks for all your replies greatly appreciated. I’ll give you an update. Hopefully my model S should be here is 12 weeks.

 

[Asterix187]

I definitely spend more in Costa than i do on electric!

The Gordano services are pretty good as well and the staff in the Starbucks are always friendly. One thing to note is its not actually good for the car to constantly charge at supercharger speeds.

 

[ShaneX]

I regularly limit my TWC to 20A anyhow, because electrical things fail because they get hot, and they get hot because they are used close to their rated capacity, so I tend to stay away from it. Well, thats my theory.

In about 1 year there really has only beeen one time when I needed to go to 32A at home, when my wife needed to rush off on a family issue with a few hours notice, and being disorganised we don't always keep the car charged up. So having a SC nearby replaces that and you are good.