valerun
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Delivery Date: 31 Mar 2013
Location: Palo Alto, CA
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E-MotorWerks JuiceBox - an open source 15kW EVSE

Sun Dec 29, 2013 1:34 am

Hi Guys,

Val here from Electric Motor Werks (http://www.emotorwerks.com/" onclick="window.open(this.href);return false;)

Just wanted to start a separate thread dedicated to questions & tech support for our JuiceBox product - a 15kW open source EVSE. As seen on KickStarter (http://www.kickstarter.com/projects/emw ... harging-st" onclick="window.open(this.href);return false;) and Engadget (http://www.engadget.com/2013/06/24/emw- ... g-station/" onclick="window.open(this.href);return false;). Since over 50 of our customers come from this forum, I wanted to make sure that we have a support thread here.

A quick refresher on the product: the DIY kits start at $149 and contain everything you need, including a 80A relay, a fully populated PCB, an industrial IP66 waterproof enclosure, chromed IP66 waterproof cable entry glands, nuts, bolts, and washers - even a decal! ;-). Just add your cables (or get them as option from our shop). Premium versions include WiFi, color LCD, wireless remote, etc - all working out of the box.

~500 if these have been shipped and already help people charge their EVs faster than ever. Over half of these are charging Nissan Leafs.

Given this is a completely open source product, we would love to hear your suggestions / comments for the next version - check out specific details at http://emotorwerks.com/products/online- ... ng-station" onclick="window.open(this.href);return false; and let us know what you think!

Thanks,
Valery & Team JuiceBox.

PS. This is one of the latest of out products. Other products features in a number of publications (EAA, ChargedEV, Engadget, etc) include 12kW DC chargers, 25kW High-Voltage DC chargers, 20kW fully isolated EV chargers, and [soon] a CHAdeMO-compatible 20kW DC charger.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

ImpactVector
Posts: 41
Joined: Thu Dec 26, 2013 9:46 am
Delivery Date: 08 Dec 2013

Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Wed Jan 01, 2014 6:49 pm

I have one question on the current sensor you sell seperately. What else is needed to make that work?

Could one simple solder it on the board and adjust the firmware code?

Thanks
-J

valerun
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Posts: 240
Joined: Sun Mar 31, 2013 1:34 am
Delivery Date: 31 Mar 2013
Location: Palo Alto, CA
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Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Sun Jan 05, 2014 7:55 pm

ImpactVector wrote:I have one question on the current sensor you sell seperately. What else is needed to make that work?

Could one simple solder it on the board and adjust the firmware code?

Thanks
-J
Hi J - sorry for lag in response (still figuring out the subscription settings on MNL, it seems).

Nothing is needed - firmware already has all the code required. Also, all required components for signal processing are on board.

Valery.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

ImpactVector
Posts: 41
Joined: Thu Dec 26, 2013 9:46 am
Delivery Date: 08 Dec 2013

Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Thu Jan 09, 2014 7:14 am

Aaah Victory!

Image

Image

Charged my Lead last night @ 7.2KW.

Only concern was the relay arm was 45 degrees warmer than ambient. I'm assuming that's ok?
Only issue was it took 2 seconds for me to work out why plugging my laptop into the USB port would stop the charger. After thinking about it I just used a header without the 5v Pin and was in business!

All in all I am very happy! Current Loop worked without touching the code.

Pwr: 7.2 KW
Time: 27.4 min
In: 3.2 KWH
238V, 30.3A
raw pV=2233,
calc pV=5903
E.M.W. 00:27
Thanks EMW!

valerun
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Posts: 240
Joined: Sun Mar 31, 2013 1:34 am
Delivery Date: 31 Mar 2013
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Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Thu Jan 09, 2014 12:41 pm

super!

re relay temp - 45C over ambient is a bit high - we normally see 25-30C rise on 40A currents. pls double-check all high-current connections for screw tightness / surface contact etc.

Thanks,
Valery
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

ImpactVector
Posts: 41
Joined: Thu Dec 26, 2013 9:46 am
Delivery Date: 08 Dec 2013

Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Fri Jan 10, 2014 7:44 pm

Valery,
I check tonight and the terminals are all 72 degrees (the box registers 55) but the copper arms on the relay register 84. Is that normal? All terminals are tight and I put copper washers under the lugs so that there isn't any question about contact.

Thanks
J

valerun
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Posts: 240
Joined: Sun Mar 31, 2013 1:34 am
Delivery Date: 31 Mar 2013
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Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Fri Jan 10, 2014 10:57 pm

ImpactVector wrote:Valery,
I check tonight and the terminals are all 72 degrees (the box registers 55) but the copper arms on the relay register 84. Is that normal? All terminals are tight and I put copper washers under the lugs so that there isn't any question about contact.

Thanks
J
hm. what about crimps? can you measure their temp up close?
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

ImpactVector
Posts: 41
Joined: Thu Dec 26, 2013 9:46 am
Delivery Date: 08 Dec 2013

Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Sun Jan 12, 2014 7:51 pm

valerun wrote:
ImpactVector wrote:Valery,
I check tonight and the terminals are all 72 degrees (the box registers 55) but the copper arms on the relay register 84. Is that normal? All terminals are tight and I put copper washers under the lugs so that there isn't any question about contact.

Thanks
J
hm. what about crimps? can you measure their temp up close?
The crimps on my cable connections are lower. They are around 60. It's just the contactor arms.

Another odd thing I am seeing ( it's a mod. Not the base product) is my juicebox appears to lose connection to my i2c rtc when the relay opens. Have you seen that before? As soon as I disconnect the car it goes back to showing the normal time.

Thanks again!
-j

valerun
Gold Member
Posts: 240
Joined: Sun Mar 31, 2013 1:34 am
Delivery Date: 31 Mar 2013
Location: Palo Alto, CA
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Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Sun Jan 12, 2014 9:35 pm

these temps are a bit higher than what we see in our units here but not high enough yet to be a real issue. I would watch them periodically, though. Another cool mod to do would be to fit a thermister on the board and do some kind of derating of the pilot when the temp is higher than 85C in the box (e.g., in the summer, under the sun, etc).

Re i2c: this is most likely noise from the relay's inductive kickback. We do have an antikickback diode and capacitor fitted in but looks like we could use more filtering. one thing you could try is a 1 ohm resistor in series with the 5V supply line from the power supply to the PCB. Another is to increase the 5V supply filtering capacitance from 50uF now (C3) to something like 1000uF.

Let us know how it works. Also, would it be possible for you to share the i2c RTC code you have added?

Thanks,
Valery
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

Levi8than
Posts: 58
Joined: Tue Jan 07, 2014 11:25 pm
Delivery Date: 21 Dec 2013
Leaf Number: 423857

Re: E-MotorWerks JuiceBox - an open source 15kW EVSE

Sun Jan 12, 2014 11:21 pm

ImpactVector wrote: Charged my Lead last night @ 7.2KW.
I'll bet the current is right, but the voltage was sampled prior to the the car pulling any load.
If you are comfortable with AC mains, stick your multi-meter across the relay while current is being pulled by the car and see what AC voltage you get.
I'll bet your line is drooping to around 218 volts. If so, this makes more sense.

If not, maybe there's some process variation in the leaf chargers and the blanket 6.6 kw is more of an average or lower bound. Not sure. But congrats, you got a faster on-board charger than I did. :)
- Joe

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