Best EV Charger for an office

Best EV Charger for an office

I am really loving my Model S and I would like to install a charger for it at one of my offices. I have a pretty hefty commute to get there, so I would like to be able to put a good charge on the vehicle while it sits. I am toying around with the idea of the HPWC, but I would like to have some flexibility to charge other company vehicles in the future (they will not be model S, but maybe other EV). It would be nice to get something that can deliver the amps to charge rapidly, but I don't see any great options. Any ideas or any good success stories thus far? I am sure I can always buy the HPWC and then replace it (and sell the HPWC) if something else comes out, but that seems silly.


DouglasR | May 20, 2013

Clipper Creek makes the CS-90, a J1772 station that will charge at 72 amps continuous. It is probably the best all-around solution, since it will charge an MS (with twin chargers) at nearly the same rate as an HPWC, but also charge pretty much anything else on the road. I don't know the price, but it is cheaper than the CS-100, which can charge at 80 amps, and nobody else makes a J1772 unit that charges above 32 amps. (All of this is from memory, so I apologize if I have misstated any of this).

shop | May 20, 2013

Can't find the CS-90 on their website anymore, just the 100 amp version:

But yes, that seems to be a good idea if you can afford $2195. It'll work with all EVs. The Model S without the dual chargers just charges at a lower rate, and dual charger equipped ones charge at 18kW.

murraypetera | May 20, 2013

Why not just an RV plug? No need for an expensive EV charger.

DouglasR | May 20, 2013

@shop - the CS-90 is still on their brochure, and I believe they are still selling it. At least those are the units being installed as part of a project to put charging infrastructure in north central Washington. I was told they are substantially less expensive than the CS-100.

@murraypetera - I do not believe that all EVs can use the RV outlet, at least without expensive adapters. Others will have to confirm.

SonomaDriver | May 20, 2013

A NEMA 14-50 plug will completely recharge a 85kWh battery in a little over nine hours. Chances are you use 1/3 of your battery or less on the commute. It should completely recharge by noon if not before.

It's much less expensive to buy/install and should be just fine for what you need.

Bob W | May 20, 2013

Go for the CS-100 (80A charging) if you can. This will satisfy the most employees and provide the quickest charging time for Model S (w/twin charger), allowing more "time-sharing" during the work day. It should be easier to justify.

Of course, your workplace main electrical panel may not have the capacity to support a new dedicated 100A circuit, in which case you may have to compromise with a CS-40 (32A max).

The 14-50 outlet is cheap (40A), but Nissan Leaf / Ford Focus EV owners can't use it at all. Those cars do not include on-board chargers or convenient mobile connectors.

jasonsc | May 20, 2013

Thanks, that CS-90 can't be that much less, since the CS60 is only a few hundred dollars less than the CS100.

Using a 14-50 plug requires that I have an additional Tesla mobile connector (I don't want to be taking my spare in and out). If I was to do that, I could get the HPWC for only about $600 more, which might be worth it for the fast charging. I do worry about vandalism on the cable, and what it would cost to put a new plug on (or how to secure it). I also am always in a rush and, quite candidly don't want to spend 5 minutes disconnecting, hanging up, etc a cable.

I also come in and out of the office quite a bit, so being able to knock out a quick charge in an hour is important.

Any good ideas how to secure the HPWC so it is immune from vandalism?


shop | May 20, 2013

A NEMA 14-50 is way cheaper - I put one in myself at our riding barn, cost me less than $100 in parts and I did it myself. Of course, it was only 8 feet from the main panel (and I got to clean up a few things while I was at it), so that made it pretty easy.

However, it would be better to put in a higher amperage charger (J1772) both for other EVs and to allow faster charging. Maybe in a year or two, I'll upgrade it...

jpeterman | May 20, 2013

The Leviton EVB40-5PT is a 9.8 kw 40 amp J1772 charger. It only requires a 50 amp breaker. Costs around $1100.

Stark | May 21, 2013

Check out these chargers:

Many options and Sun Country has installed a few thousand accross Canada

bt77057 | May 21, 2013

An important point to consider is that the Tesla charging adapters only rate up to 50 amps. So even if you buy something that will deliver, 80 or 60 amps, the Tesla adapter itself is configured to tell the car which one it is so that the car will select the appropriate amps to draw from the circuit.

It is also my understanding that on the car's charging menu, you can only select amps down (derate) the charging amps, not go up, even if the circuit is rated higher.

jat | May 21, 2013

@bt77057 - the J1772 adapter can charge up to 80A, assuming you can find a J1772 EVSE that supplies that much current.

Brian H | May 21, 2013

A few thousand? I don't think so:

Many, but not that many.

jbunn | May 21, 2013

Your best bet is to run a 50 amp circuit for your car. Install for other later. Charger, not needed.

DonS | May 21, 2013

If you need J1772, then CS-100. (CS-80, CS-90 and CS-100 are the same hardware and the same price, just software limited if your building supply cannot handle the CS-100.)

DouglasR | May 21, 2013

The CS-100 costs $2,195 from Clipper Creek. It won't charge a Roadster unless it is derated down to 72 amps, but otherwise it will charge anything.

The CS-90 costs $2,099 from Sun Country Highway, and it will charge anything; for a Model S with twin chargers, it is about 90% as fast as the CS-100 or HPWC.

The HPWC costs $1,200, charges at the same rate as the CS-100, but is limited to the Model S.

A NEMA 14-50 plug is very cheap, charges at half the rate as a CS-100 or HPWC, and will charge some but not all EVs.

It seems to me those are your main options.

caolivieri | May 21, 2013
DouglasR | May 21, 2013

Well, yes, but they are 30 amps, slower than any of those I've mentioned, and probably just as expensive.

jasonsc | May 22, 2013

@DouglasR, thanks for the succinct overview. I complained about the cost of the HPWC earlier, but compared to the other options, it is a good price. Too bad it is limited to the Model S, but that probably makes sense. One other consideration, which is now becoming a reality, is that the potential for vandalism or theft is a big deal. This is an office area that gets pretty dead at night, and there are issues of theft and cars that get broken into. I would have to find a way to secure a charger, which I am not seeing any good options right now (I guess I could build a wood box). May end up going with just the 50 amp plug and an extra mobile charger, even though I lose a fair amount of speed. For instance, yesterday I was just at the office for a few hours, and could have charged up with a full 72 amp charger, but not with the 50 amp version. Oh well, tradeoffs....

If anyone has a good idea on a secure solution, let me know. I would be really upset if I had the connector cut off. I bet that would cost a pretty penny to replace....