7kW or 22kW at Work Location - Model 3

[Buzza]

Hi All,

I am after some advice on what charger to have installed at my work premises.

I have had a Model 3 for just over a month and really need to get a charge point sorted! We also have a Seat Leon PHEV and in the next 12 months another PHEV which needs to use the charger.

My question is, am I better going for a 7kW or 22kW charger (I understand that the 22kW will only charge the M3 at 11kW (and the Leon at 3.4kW(?)). The electrician who quoted said PodPoint recommends the 7kW as the 22kW won't offer much of a benefit, it will also allow for more capacity in the future should we get another charge point. Although it looks to me like there is lots of capacity in our distribution board.

However, I want to be able to charge the M3 as quickly as possible to allow others to charge, and don't want to charge every day. I also want to be able to run the M3 battery down lower, (because it takes so long to charge off the mains plug adapter it can take 2-3 of days charging to get it back to 100% which is not ideal).

Price difference is £250 so money is not an issue. We also have 3 phase supply available.

 

[DenkiJidousha]

Of the choices offered, for the sake of just £250 up front, I'd go for the 22kW. You'd get faster charging on the Tesla Model 3, as would many other staff cars (e.g. many Zoe cars can charge at 22kW AC).

However, I'd rather go for at least a double unit or a pair of 7kW chargers - even for a small office that flexibility seems a better bet.

 

[M3P75]

I had the same dilemma, we installed the 22KW in the end as it covers us for the future, if you go for the 7KW the cable, rcd etc won't be any good if you decide to go to 22KW at a later date.

 

[WannabeOwner]

charge the M3 as quickly as possible to allow others to charge

Have to do the car-shuffle for that.

We put 10 chargers in the car park (total 20 cars). Local council (or some other fund) stumped up 50%. We were having some electric work done at the time, so running a cable sufficient for "all around the car park" was not a big ask.

Previous to that when I got the Model-S back in 2015 (big chunk of change, back then so didn't expect any other likely contenders), I put a single charger in. We had had the carpark repaved a bit before that and told them to "Put a duct in for future car charger" to be able to get power across to the perimeter. Came to install a 3-Phase charger ... and the cable wouldn't fit through the piddly duct they had put in ... so that first one was single phase. In fact its been fine (if at work 9-5). Its been rare that I've been at a meeting somewhere else and only in the office for a few hours, such that 3-Phase would have helped (Model-S/X faster on 3-Phase than Model-3/Y)

Can't remember what brand the other chargers are (but I can find out if you are interested). There is a phone APP and a QR code on each one. EV employees get "Accounts" set up, and then can just scan the QR code on their APP and initiate the charge. I don't think we restrict usage, but I'm pretty sure the setup allows for all that (and stats of who-had-what). They aren't very fast (but we're not in the game of topping people back up after a weekend trip to the Outer Hebrides! its intended to, roughly, be their commuter mileage - might even be restricted to 4 hours a day (I can't exactly remember). Anyway : It's Flexible, and we could charge-for-use if we were so inclinded.

If we have a visitor they can just plug in, make a note of the "stall no." and Admin can start a charge [for that stall]

If you are only putting one charger in I'd do 3-Phase for future-proof and the occasions where you are only at work for limited hours. But I'd consider assuming that most/all will have EVs at some point, and anyone without off-road parking will thank you for the facility (even if they have to pay etc.)

 

[WannabeOwner]

P.S. I reckon we did the car park electrification 3 years ago. So far there are only two others EVs in the company - and an Outlander that doesn't really count.

Bit disappointing really. We've had no interest in Salary Sacrifice (other than a fair bit of "Might do it in future" ... no doubt some will not be ready to replace their current car yet)

 

[qwickshot]

It’s really a compromise. The 22kw point is great for now but it removes capacity for installing more cheap relatively dumb single phase chargers later. Power capacity tends to be the long term bottleneck rather than anything else.

You can have 3 7kw plugs or one 22kw plug for the same power capacity cost. In the long term for ‘long stay’ parking like a work car park, more 7kw plugs are generally better than fewer faster 22kw plugs.

Yes I understand you can get load balancing plugs but they do come with an additional cost and complexity.

Personally, I’d go 7kw and if you can, put in the cabling or ducts for more chargers at the same time if having quite a few plugs in the long term is the priority.

 

[MrBadger]

You can get 3 x 7kW (3 x 1ph 32A) charge points for the electricity requirements of a single 22kW (3ph x 32A) charge point which for a Tesla will only give (3ph x 16A) anyway. 7kW is still going to give, in approx terms, 10% charge per hour, so ~80% in an 8 hour day depending on the type of car. That's 3 cars simultaneously, no swapping over, more chance of finding an unoccupied charge point.

TBH, 3kW would work for most just as well. You would then have 7 charge points (7 x 1ph x 16A) that would give ~40% per 8 hour day.

 

[WannabeOwner]

If its commercial premises is it likely to have a limit on 3-Phase that is going to be troubled by a dozen car chargers? (I have no idea)

I don't remember us having to "upgrade" anything when we put 10 in ... we are just office workers, with (presumably) a commercial 3-phase supply - which may well have been intended / configured to support light industry.

 

[UkNorthampton]

You can send these people an offline message (bottom right) - https://artisanelectrics.co.uk/

Their Youtube channel has a wide range of chargers including ones with load-sharing, billing and future proofing.

eg

but more appropriaet ones somewhere in here

Playlist (86 videos)

 

[NewbieT]

Our office has 9x 7kW and two plug-in cars. Very few people are now in the office (WFH) so no car shuffling needed. 7kW is pretty perfect for charging 10% to 90% during a normal working day. I’d pass over 22kW for one person vs 7kW for 3 people any day.

 

[Jason71]

Our office has 9x 7kW and two plug-in cars. Very few people are now in the office (WFH) so no car shuffling needed. 7kW is pretty perfect for charging 10% to 90% during a normal working day. I’d pass over 22kW for one person vs 7kW for 3 people any day.

this is the point I think. You can get almost a full charge in a normal working day with 7KW so if this is the use case then more 7KW makes sense.
If however you are in and out during the day visiting clients etc so are there less you will benefit from the 22KW except how many cars are there now that charge at >11kw

Could you get the 22kw then limit it to 11kw ( most chargers have this facility) then it is going to give you the max without stopping more chargers being fitted.

Batteries of course will get bigger in future and take longer to charge...

 

[GRiLLA]

So this would be future proofing yourself ...

Charger built for massive load balancing on a single feed, so you can add more and get the most out of your available site power.

 

[94jdh]

I've had two 22kW charging points installed at work. Each charger has two type 2 connectors so it will charge up to 11kW per port, or up to 22kW per charging point should cars support it in the future.

 

[Mrklaw]

what % of EVs can properly utilise a 22kw charger? And I don't mean 11 as at that point you'd definitely be better off just goign with 7.

7 lets most people fully top up during work hours, it charges slow enough to not put pressure on people to move their cars during the day unless you have more EVs than sockets (also less likely with 3x7 rather than 1x22), so should also be easier to live with and administrate

 

[M3P75]

what % of EVs can properly utilise a 22kw charger? And I don't mean 11 as at that point you'd definitely be better off just goign with 7.

7 lets most people fully top up during work hours, it charges slow enough to not put pressure on people to move their cars during the day unless you have more EVs than sockets (also less likely with 3x7 rather than 1x22), so should also be easier to live with and administrate

At my work, only the Porsche Taycan can.

 

[WannabeOwner]

I don't mean 11 as at that point you'd definitely be better off just goign with 7.

11kW is 57% faster than 7kW, isn't it? Not exactly insignificant And presumably the "climate etc" kW is the same, so a larger portion available for actual charging.

But, yeah, Zoe, Model-S/X, Taycan (Post 2021) and BYD maybe?

I can't see more models adding 22kW charging because of the extra cost and batteries up to about 100 kWh can be charged from 10%-90% in 8 hours


When bigger batteries come then faster charging may be helpful ... but you've still got to have "been somewhere distant" to need to fill the battery that much.

Or you are towing something

EDIT: Audi e-tron and 55Volvo C30 Electric can maybe charge at 22kW ?

 

[Adopado]

11kW is 57% faster than 7kW, isn't it? Not exactly insignificant

Yes, I've done a couple of charges at 11kW and it's a noticeable and useful bump in speed over 7kW. 2 good charges in the day rather than 1 perhaps. The double 11kW charger option as described by @94jdh looks like a great compromise.

 

[Gezz]

We put in 3 RolecEV dual 22Kw chargers (About £1350 +vat each) , they have a key to control access on each port. We ended up buying chargers and getting them installed when some ground work was being done. The 3 dual 22kW we less installed than PodPoint we quoting for 2 single 7kW . Plus we have ducting ready for another 2.

All the sites I work on in UK and Ireland have 22kw chargers now , I still need to supercharge but I can depart work with a full charge .

If you have 3 phase available go for 22kW it is worth it and gives people options going forward.

.

 

[thewishy]

I would think about what your intended usecase is. If you have only employees charging, and most employees have an 8 hour day, then 3 x 7kw is more useful than a 22kw double (1 x 22, 2 x 11).
If you have business guests who might be there for a shorter period of time, or "field" type people who might be there for half a day, then the 22kw double wins out IMHO.
If may also make sense to think about 3.5kw for those with plug in hybrids, who will no doubt clog up the proper chargers otherwise.

Could I also suggest unteathered, you'll likely get the budget to do this once, and if some tit runs over the cable you're waiting a long time for budget for replacement. Plus the longer cables typically carrier will allow for an iced bay without loss of charging. Or indeed EV users to swap over half way through the day without having to move their cars.

 

[yessuz]

i would think that more 7KW charging points is better than less but 22 kw :/ especially in office where car is supposed to be parked for long time.