Charging query - 2-phase supply

[FootSore]

I am about to buy a Model S - I have a number of queries on charging that I have really struggled to find the answers to.

Background
We run a set of holiday cottages that are heated with night storage heaters, and so have a decent supply. We have two phases (like 3-phase but someone ran off with the third phase). So it effectively operates as two single phase supplies, although has a 3-phase meter. We can pull 90kW at night in winter, roughly 45kW per phase which at 230V is 196A *2. Having a 3-phase upgrade is £35,000 to the transformer, and figure £5-10k internal costs to run cable to transformer (400m), and associated amendments to frig things about in electric intake room - not happening. Elec load tails off about 4am, and we won't touch 30% of peak for rest of day. We also have 10kW of PV panels and 8kW of inverters on each phase. So we can have nearly 8kW spare per phase in summer depending on what pool is doing. Transformer and cables good for 120kW.

Questions
I need to block charging between 00:00 & 04:00 otherwise I exceed Available Capacity charge and get penalised by supplier. Can this be done in the car or ideally the charger (I can do it easily with time clock and relay)

A Zappi is on the shortlist so I can use excess PV in the summer. We often export 6kW for 8-hours during the day in summer, and often work from home, free sounds good.

Can I run dual chargers with two phases, 32A per phase (or more) for 04:00-07:00 would give me plenty of charge at £0.07/kWh (£10k elec bill). Is this two cables running to the car or one? The other option is to allow charging beyond 07:00 but that costs £0.12/kWh

Could I run dual Zappis to charge from PV on each Phase. The available PV load will differ between phases.

All charge points likely to be available to guests, although we have only had 1 EV here ever, quite a few hybrids, but this will change. Costs of installation or duplication of kit aren't my priority.

You can guess why I have struggled to find out this info! Can anyone help on any points.
Dave

 

[sidmini]

block charging

Hi!

The only control you have in the car is when to start charge at a preset time which can be saved for your geolocation. So you can sta
rt the charging at 4:00am and then just limit the amount your battery is charged by capping it to 50% to 100% via increments on the dash control or through the iPhone app. It might be possible that there are third party apps that give you more control. I know the tesla wall chargers have load balancing if your plug 2 of them together. It might be worth chatting to the service centre to run through the technicalities.

If you are looking to buy feel free to use my referral code which will get your free unlimited supercharging for life, check out my profile page for the link.

 

[FootSore]

Sid,
Thanks, that gets me over first hurdle. I can go to bed knowing the car won't start charging until the storage heaters are done. I can then tweak the charge amount depending if I'm at home and car is school run duties only or doing a decent run out. Although may have to charge evening before for that unless I can get serious Ampage into the car as sometimes off about 6am.

Dave
P

 

[sidmini]

Also as you are running a business, you might be interested in contacting tesla and asking for the destination charger team to get in touch with you. They will send you the wall chargers for free, you pay for the install and offer free electricity to guests and patrons. Worth finding out more. You will be listed on the tesla navigation as a destination charger and could potential drive more business to you I have sent you a PM if you want to chat.

Alsoeach single phase in theory will get you 21 miles per hour of range. So roughly a battery at 0% can be charged to full in around 10 hours

 

[sidmini]

Also don’t forget to use the OLEV government grant for £500 your charge installation, I’m sure you must be aware of this anyway. Unfortunately the grant won’t work on Tesla’s wall connector as it doesn’t send data to the govt. it will work on Zappi, podpoint and others...

 

[sidmini]

Sorry for the multiple posts I’m using my mobile. This 3rd party app called VISIBLE TESLA might do exactly what you need with specific start tops scheduled charging, see the link below

The Scheduler Tab

 

[WannabeOwner]

I need to block charging between 00:00 & 04:00 otherwise I exceed Available Capacity charge and get penalised by supplier. Can this be done in the car or ideally the charger (I can do it easily with time clock and relay)

This is presumably only in the Winter when you are using the Night Storage heaters?

TeslaFi (and similar 3rd party APPs) can do schedules of various sorts. TeslaFi could, for example, stop charging (if it was occurring AND the car was parked at "Home") at 00:00, and start charging at 4AM. However, this relies on network connection to the car, so would not be guaranteed 100%, so if exceeding load, even once, triggers some max-capacity-used penalty then your time clock might be better, and more certain. If the penalty is just for the duration of over-use then you might live with it as I doubt it would happen often, and maybe not at all.

If the car gets a "power cut" during a charge then it will resume charging when the power cut ends / power resumes, so I think the clock thing would work.

You can dial down the AMPs on the dashboard (I am not aware of anything 3rd party, including the Tesla Phone APP, which can do that) , in case that helps. Not much good if you want to reduce it 00:00 to 04:00 and increase from 04:00 to 07:00 ... unless you are an insomniac

 

[arg]

I need to block charging between 00:00 & 04:00 otherwise I exceed Available Capacity charge and get penalised by supplier. Can this be done in the car or ideally the charger (I can do it easily with time clock and relay)

If your capacity charge is punitive, I'd be inclined to do this at/before the chargepoint. The timeclock and contactor approach will work, though is a bit crude.

If you are going Zappi, it can monitor the demand and avoid exceeding it. eVolt can do similar. There are various 'hacker' solutions using the Tesla WC but not, so far as I'm aware, any commercial solutions there. I'm not sure what PodPoint can do with their three-phase gear; I think their hardware can do what you want but they probably don't have the right software for it at present.

A Zappi is on the shortlist so I can use excess PV in the summer. We often export 6kW for 8-hours during the day in summer, and often work from home, free sounds good.

Sounds good, but not necessarily worth the bother to maximise it - if you end up spending extra money that you wouldn't otherwise have spent in order to maximise solar usage, the return on that investment is likely to be very long or negative. And it's not necessarily "greener" either. But you might get it as a side-effect of what you already need, and you can get a good chunk of the benefit manually.

Can I run dual chargers with two phases, 32A per phase (or more) for 04:00-07:00 would give me plenty of charge at £0.07/kWh (£10k elec bill). Is this two cables running to the car or one? The other option is to allow charging beyond 07:00 but that costs £0.12/kWh

Yes, with the Tesla WC they specifically support using two phases (as well as the more common single phase or three-phase).

Depending on the age of your Model S and whether it had the dual/enhanced charging option when bought, that would give you 7kW (16A x2), 11kW (24A x2), or 14.7kW (32A x2).

That's to charge a single car from the two phases - of course you could fit two separate chargepoints, one to each phase, and charge two cars.

Could I run dual Zappis to charge from PV on each Phase. The available PV load will differ between phases.

Yes. The Zappis and the cars will be unaware of each other and what's happening on the other phase.

 

[ai4px]

Given that you want to exclude 00-04am from charging, the simple solution is a timer such as an electric water heater timer. However, the inner geek in me says you can muck with the proximity pin on the charger cord and allow the car to stop charging much more gracefully.

Siemens versicharge has a jumper block that you can hook wires to that inhibit charging using a very very small relay (logic level signals). But I cannot recommend the versicharge since it faults out occasionally when the car starts charging after it's been plugged in a while. If you don't plan to use scheduled charging (from teh car) and simply want an EVSE that is easily controllable, then versicharge is for you. Not sure how it'll work with your odd "2 phase" though... scratching my head on that one....

I'm ordering a current sense relay today to use with the versicharge. I'll sense the current draw from the Tesla HPWC and when it gets above a threshold of 10amps or so, the current sense relay will activate and disable the versicharge via that jumper block. We have two EVs and two EVSEs on one 50amp circuit. I'm trying to make sure they don't draw more than 40amps at any time

 

[FootSore]

Some great info, thanks guys. As a former VW Phaeton owner I know how important these forums are, because the manufacturers don't know enough about their own cars!

Siemens Versichere looks neat but is expensive (I think I saw £1300). The remote function is really neat. I mess about with Spark Photons and firmware to open/close relay would be straightforward. With a bit of work it could even monitor power, true geekery!

I talked to a local-ish installer (Phoenix EV) and we are tentatively scheduled to have a Zappi installed next week (with grant) so total cost is £350 or something (I can reclaim VAT, as will be open for customers to use). They are just reviewing my photos for installation. The export limiting thing seems to cover all my bases - as someone pointed out heating is only in winter.

As we can export so much I am reasonably confident that half the week the car can be topped up with PV alone - free miles is fun. If I'm away for work it may need to be topped off with paid for energy. My mileage is either 0 or into 100s of miles, if I'm not driving then the wife will use for school runs (2 miles each on rural fast roads - not its not walkable from safety perspective much as I would like the kids to walk to/from school).

Will be in touch with Tesla charge team as well - see if I can get a charger - but will wait until I have got there first one in and used. We only have one car, so only get grant.

Car is a 2018 Model S 75D (1500 miles on it), enhanced autopilot, and premium pack. Midnight Silver and black interior. Located in Gatwick but being moved to Leeds. Hopefully have my hands on it shortly.

I have seen some straps to lift the boot flap automatically on opening the tailgate. Are these available in the UK? Some upgraded LED boot, puddle, and frunk lights are next on the list.

Thanks
Dave

 

[arg]

(with grant)

(I can reclaim VAT, as will be open for customers to use)

I fear you will find that the OLEV grant and reclaiming the VAT are mutually exclusive - see Q9 on page 10 of the grant terms.

 

[FootSore]

I fear you will find that the OLEV grant and reclaiming the VAT are mutually exclusive - see Q9 on page 10 of the grant terms.

Good spot - hadn't read the T&Cs, I presume the installer would have made me aware fo this. So will refuse access to customers. Will then submit for a workplace grant for the second one. We have at lease one employee with an EV (me), although my journey to work is 0 miles.
Cheers
Dave

 

[WannabeOwner]

I have seen some straps to lift the boot flap automatically on opening the tailgate. Are these available in the UK?

Pretty sure I've only seen them state-side. I think they would e a good idea - I'm always leaving the flap up, and then it annoying my when I notice it, driving, but can't be bothered to stop, get out, sort it out, and carry on again ... so it annoys me the whole journey! the flap-straps would solve that

 

[sidmini]

lift the boot flap automatically on opening the tailgate

I believe you can buy the tailgate lift straps and upgrade boot lighting for abstract ocean in the states. Check out Oscar & Hamish for very cool luggage for the frunk, boot “coffin” and side cubby holes in the boot. Let me know if you want a referral code for 10% off

 

[GeorgeSymonds]

You'll could in theory charge using 2 phases but this will depend on the charger you're using and whether it complains, The Tesla supplied UMC in the UK can run 3 phases at 16A or 1 phase at 32A - I suspect that using that with 2 phases would be limited to 16A per phase and give you nothing over a single phase at 16A. Newer UK cars are limited 24A 3phase and so again you're not getting much more than a single phase at 32A if you're only running 2 phases - I think I'd be inclined to stick to single phase.

The car timer approach isn't going to work well for you if you're allowing guests to charge as you have no control over their settings, and if they're none Tesla they'll work differently. I think you're most reliable setup is a pair of single chargers, one on each phase and with an external timers that can switch 32A, If you just need to keep below an overall capacity you can get 16A single phase chargers that do what they say, obviously it takes longer to charge.

 

[FootSore]

Well Phoenix Works were here today installing my new Zappi. Had sent plenty of photos, a diagram, and an explanation of four possible locations for the charger in ascending order of preference, but also difficulty of install. The guy did a really good job, OK I had had a think about the route. Through a wall, behind a washer, round a unit, past the dryer, up some pre existing trunking holding a water pipe, through a brick wall at an angle, with the pipe, into the floor void of a bedroom. Carpets up, floor boards up, across the room under floor into main cabling channel for house. Into outbuildings, across garage, and into house MAIN fuse box which feeds local fuse boxes, heat pumps, and PV input. CTs installed (on CAT5 ran next to power cable), Zappi installed, and late lunch had! But the installer was great.

Can't test the charger functionality but looking at menus will do what I need. Limits load to 63A back to main site fuse board, so if our heat pumps are running it won't cause load to breach site MD of 90kW. When finishing install house was merrily exporting 7kW of load (and using 1kW) - where is that Tesla - it's missing free miles.

Email from Tesla, it is now 'In Transit'. So on way from Gatwick to Leeds. Then it will have to be prepped, so mid next week hopefully.

Thanks for the info. Will digest some of it and send query to Tesla via Sales Team for info from 'Destination Team'. Although if the Zappi does the right job I might put another one in on other phase for guests. There is an OLEV grant for employers but have to apply and wait to get it.

Cheers
Dave