JuiceBox Enhancements

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Dsinned

Well-known member
Joined
Nov 6, 2012
Messages
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San Jose, CA
Being a JuiceBox owner, one of the best features of the competing OpenEVSE is that it apparently has a RTC function in hardware.

This feature is not (yet?) available in a JB; not even in the so-called "Premium" unit. Because of this I have to repeatedly set "the clock" running in software to the correct time, so the timer initiates a charge at the actually scheduled time. Setting the time can be easily accomplished with the Remote Key Fob and menu driven user interface on the uLCD, but still a PITA, because it has to be done so often. I'm told with the WiFi option, the JB will eventually be able to set/maintain the actual time via an Internet connection, as well as self-update to newer versions of firmware. Once that is available JuiceBox will surely become more popular with the EV community.

In order of priority, with perhaps an increase in total cost, here are my "wish list" items for the JuiceBox:

1. Real time clock
2. iPhone App
3. Larger display screen
4. Safety Agency approval
5. Dual J1772 (40A total) outputs for charging two EVs in a load sharing mode, or sequentially

The first four are probably in the works for release to production by early next year. The last is truly a wish list item but would be a highly desirable enhancement for those of us that already own/drive two EVs. The time it takes to fully recharge my two EVs on average is around 4 hours each, so a dual output EVSE should still be able to complete an overnight charge of both cars during off-peak rate periods.
 
pchilds said:
Three if the five are already available on the OpenEVSE. Maybe you bought the wrong product.
Actually 4 out of 5. NickS built "Hydra" it is based on OpenEVSE and splits 1 input to 2 vehicles.

Number 5 is not likely to ever happen for a kit product. NRTLs will only certify a complete product not anything at the component level.
 
Hmmm, that must be a new product from eMW. I never noticed it before in their online store. I bought just a regular J1772 connector socket that screws on to the wall for $20 online. I like this design much better because it includes a built-in hanger for the cable. Not too shabby for only $25. :mrgreen:
 
On Christmas Eve, I went to a relative's house in my VOLT about 50 miles from home, and took my JB with me so I could do a recharge while there several hours. Unfortunately, I forgot to take my JB Key Fob, so I could not activate a FORCE charge while still preset to do a scheduled charge by its internal timer after midnight.

Without the key fob, I was screwed even though the VOLT itself was preset to "Charge Immediate". In this scenario, the car can only wait for the JB to initiate charging, when set to activate by the timer. Which it of course, it cannot do because it was previously preset to only activate after midnight.

Also, every time you plug in a JB, the internal clock setting does not re-sync automatically to the actual time. Eventually, it may be able to do this via the Internet, but while using the JB as a portable unit, internet access may not be possible, thus exacerbating the situation all the more.

A nice enhancement to the "Premium" JB would be a workaround to this situation. It needs to have a way to "force" an immediate charge, independently of a preset charging schedule, AND without a key fob.

Perhaps, a simple miniature toggle switch accessible on the outside of the enclosure could be used to control the Arduino software to put the JB into an "Override" mode. When set to this position, the switch would inform the JB to act like it is controlling a "Basic" JB instead of a "Premium", without LCD display and key fob, to go into the charge immediate mode.

To save cost and avoid "tampering" this switch could be mounted on the inside of the enclosure. Less conveniently located, but everybody has access to a screwdriver so the case can be removed to access inside the enclosure for just such a situation.

Of course, a Basic JB does not need this switch, however I have the functionality of the Premium JB in a BASIC unit. I have interfaced a compatible 4D Systems Goldelox display module in to my basic enclosure, and modified the Arduino firmware software so that it essentially "thinks" it is controlling a Premium unit. With the external switch set to the override position before power up, it should be easy to nullify the internal clock/timer functionality.

A neat little feature like this would be GREAT for forgetful people like me and anyone else using their JB EVSE for portable use!
 
Dsinned, I've been entertaining similar thoughts in something of the opposite direction (something to CANCEL an already forced override, so that unit goes back to timed charge only).

Anyway, your end goal might be made easier by mounting a momentary switch on the outside of the unit and modifying the code to check the condition of the switch at power-up (or within some window of time, that only you would know, from the instant power is first applied).

Alternatively, if you wanted to create a little more secure arrangement, you could establish a "secret handshake" or sorts by modifying the code to require the button to be pushed within X seconds from connection to vehicle and then held for Y seconds. (Unit boots up dependent on state of switch at target time.)

Since the JB Premium has plenty of space inside, you could also install a magnetic sensor (only you would know where it's positioned). Not sure the metal casing would allow for this though. If there are some extra conductors in the line cord, you might be able to hide the sensor inside the body of the input connector.

If metal casing prevents use of magnetic sensor, you could consider something else like a light sensor or a mercury switch (only you know the right angle and the right timing).

These are surely low tech security measures, but it seems unlikely that the would be violator is going to have time to figure them out. They'll just think the charger doesn't work.

I'd be interested to hear what you decide on.
 
My current thinking for the most cheap and dirty solution is to attach a velcro stick-on pad on the JB enclosure - probably inconspicuously along the side somewhere - and use that to hold the key fob when not in use. Of course, something like this is not foolproof, but surely should help. :mrgreen:
 
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