Electric Motor Werks - JuiceBox

Electric Motor Werks - JuiceBox

Has any MS owner installed this device which makes some substantial claims about enhancing charging activities. They state: "The device is a full-featured J1772 charging station and supplies up to 60A 15kW to your J1772 vehicle (all production cars sold today) and operates on any voltage between 100V and 240V. They offer kits for those that have kit building skills, or the Premium Assembled unit by them costs $359.00. The Premium unit vs. the Base unit offers these features: Unique Custom Enclosure, Time-of-day charging, Remote control, LCD display showing power, total energy, $ saved, etc." Has anyone installed this unit? Check out their web site at:

MS ETA = December 2013.

shop | 18 October 2013

I bought one of their kits via the Kickstarter campaign. I haven't got it working yet, but others have. Seems OK. In hindsight, I would recommend just buying the finished box, rather than the kit. The base assembled version costs just $249 for a 60kW J1772 charger (without the cable, mind you). Add an extra $229 for a 70A 25' cable. And then you have to provide either an input cable or conduit to supply the electricity.

It is still cheaper than any alternative if you want a high power J1772 charger.

But bear in mind that you get what you pay for. No UL certification. They are still changing the build as I type this, tweaking this and that. No displays or GFCI (unless you buy the premium version).

Also, most MS owners don't need one of these. I'm buying one just to install at my commercial barn for others to use.

cmanchen | 19 October 2013

I bought the premium assembled unit. It hasn't shipped yet, but it should be interesting.

gasnomo | 19 October 2013

So I actually asked a person at Tesla Motors about this before...Here is what he said, fyi, my 'problem' referred to below is i wanted to see if could use this during a blackout to plug my MS into my 110 on my backup generator panel to charge faster than at 110:

“This looks like a UMC with adjustable amp output. Clever, entrepreneurial, yes. I do prefer the Tesla UMC even with its 40 amp pilot. It can be used with a 14-50 adapter on 220 V if the car is dialed down in amps to match the power source such as a home generator. The simple answer is if you try to pull more amps than a source or generator can handle, you will pop a breaker or stall the generator.”

It is hard to tell from the company’s website, if their charger is more than a simple Model S UMC charger. Do you know if they require that the unit is connected to a 220V source? If so then all they are doing is creating a potentially cheap alternative to existing products but it would not solve your problem.

If on the other hand they only require a 110V source and there is some black magic happening inside the box that makes it possible to pull more than 15A from a 110V source (not really possible without tripping home breaker); then they might be on to something.

Either way I don’t think it is the answer to your problems. Your probably better using your tesla charger. Charge time really depends on the power available, we have successfully charged cars at 240V using massive diesel generators but in most cases generators can really only provide standard 110V 15A power. Which as we both know is really slow going when trying to charge a Model S!

I guess I don’t understand where they are getting something for nothing. For any given power source you can only extract X amount of power over time. A magic box in the middle can’t create power, it can only store it. So if it is an energy storage device then it may help, assuming it was charged prior to the blackout. If it is not an energy storage device then it is essentially the same thing as your existing charge cable. I’m guessing the latter is closer to the truth. That would mean the only real advantage their product has is that it is cheaper than a model S charge cable.

But since you already have a model S charge cable . . .

Also there is usually a reason things are cheaper. The Model S charge cable has many built in features to prevent damage to your car or home. Don’t know about their product. If it checked out it would be a nice cheap alternative but, I guess I wouldn’t really recommend it."

That's direct from Tesla.

stephen.kamichik | 19 October 2013

I am considering buying their kit ONLY because my wife's electric car requires a J1772 charger. I would use it as a Level 2 charger for my wife's car.

CA_Kid | 19 October 2013

For: CMANCHEN Do let me know what you find out. I'm quite interested.

For: GASNOMO To answer your question. They state on one of their web pages: "There is an automatic power derating for 120V outlets so you don't have to worry about overloading your house wiring in that unfortunate event when you have to resort to 120V charging.

At the moment I have no charging ability where I live. The CCRC retirement community flatly refused to install a 240V station as too expensive ($5,600). I am currently trying to get them to install a 120V station. Accordingly, I am interested in seeing if this JuiceBox may assist with this charging situation.

shop | 19 October 2013

You don't need a Juicebox to charge at 120V. The Tesla UMC charges just fine at 120V. In fact, the Juicebox limits itself to 15A maximum draw for 120V sources. The Tesla UMC can draw up to 16A when using their NEMA 5-20 adapter.

If you don't do much driving, you can by with 120V charging. It is possible the community already has a parking spot with a 120V plug nearby. I'd go for a walk around ALL the parking areas and see if I could find something. Often in CA they install outlets to charge electric golf carts.

If you drive a lot and want 240V charging, you don't need the community to install a charge station. Those ARE expensive. All you need is a 240V electrical outlet. It is even possible they already have one there, again check.

Finally, CA law states that any rental or condo facility can't block you from installing a charger or plug for an EV, however it is up to you to pay for it.

CA_Kid | 20 October 2013


The problem here at this CCRC is that all the parking spots, some covered and some not, are all assigned. While there may be an isolated 120V outlet at one or two of these spots, they are reluctant to ask a current resident to vacate their assigned spot just because another resident chose to buy an EV. The maintenance department has a variety of 120V outlets around the campus, but they are reserved for their use only. Currently attempting to get them to install a 120V outlet at my assigned stall.

Brian H | 21 October 2013

Buy an assigned stall with power from the current user.

shop | 21 October 2013

Get them to install a 20A 120V receptacle on a dedicated circuit - make sure they use a 20A GFCI receptacle (since I'm assuming all the receptacles have GFCIs on them) with a horizontal blade.

You can then use Tesla's NEMA 5-20 adapter to get 33% more charging speed than a regular receptacle.

Sudre_ | 21 October 2013

I am not saying the Juicebox is a bad investment but I do want to just clear up any confusion I might have.

The base unit, not assembled is $149
The needed J1772/cable is $189
The 14-50 cord and plug is $49
An extra J1772 to Tesla adapter is $95 (optional)
For a total of about $550 including shipping, $650 assembled.

This does the same thing as the Tesla UMC?
$667.92 after shipping.

shop | 21 October 2013

If you just use a NEMA 14-50, then yes, it'll output the same power as a Tesla UMC. But it'll have a J1772 adapter plug which is useful for other EVs. Really, the Juicebox is meant for other EVs, not as a Tesla charging solution.

Also, the Juicebox will output up to 60 amps continuous, not 40 amps like the UMC - it'll need a hardwired input connection for that.

Consider it a competitor to Clipper Creek J1772 chargers...

buy | 23 February 2015

My experience with JuiceBox has been horrible. Installed the box in Nov 2014, worked fine for two months and then stopped working. Sent numerous e-mails to company, no reply. It has been more than two weeks now I have been trying company to respond to my e-mails. There is no telephone number, whatever number I could find on the web straight goes into voice mail and at the end of the voice mail you get to hear" Mail box is full, you can not leave the message. Good bye". Don't understand why anybody would spend $600+ on such inferior product with zero customer support.
Thinks twice before you buy this product. I would rather pay few dollars more to buy a product from a company that stands behind its products