Better charging controls

[Wee John]

No timers are necessary, the remote can be set to turn on the charger after a set delay and can also turn off the charger after a set amount of charging time, it looks like the car remembers the time the remote was set as you don't need to reset the times the following day. I tried to post pictures from the owners manual but they came out huge, not suitable for posting.

 

[MtnViewMark]

Indeed, I can confirm this, now that we've been using our Level 2 EVSE for about a week. The remote does remember the time of day for start (and optionally stop), even though the user interface is in terms of hours of delay.

For example: On Monday, you come home at 5:15pm, plug in, and set the start charge delay (with the remote) to 7 hours, then the car will start charging just after midnight. If, on Tuesday, you come home at 9:45pm, plug in, then turn on the remote and tap either of the adjustment buttons, it will show a delay time of 2.5 hours, just what you want to start just after midnight.

Note that in all cases, when you plug in the car, it starts charging immediately. Then you need to turn on the remote, select a delay time (even if it is just tapping the button to recall the setting), and then send the delay charging command to the car (another press on the remote.). Then, after about a minute, the car will stop charging, and wait for the set time to start again.

Since the car is actually the device doing the timing, my one wish is that there were a button right in the car (or perhaps in the charging well!) that let me select delayed charing right when I plug it in. Then I would have to fiddle with the goofy remote.

 

[fjpod]

In my garage, i have a commercial type Intrmatic timer that I used to use for my pool filter. I run my imiev oem chargr from that timer. As much as I have mastered the remote, I find my timeer is so much easier. I dont even set the time of day properly. Just pull the wheel to set the delay and adjust the off switch for the number of hours charging time I want. Walk away, I'm done.

Oh, BTW, the charging will start when the timer turns the juice on, even though the cord was plugged into the car first.

 

[JoeS]

Reviving this old thread...

I've been using my Remote almost every day since I bought the car in February. I rarely use my Remote to delay starting a charge, and do use it at varied times during the day to terminate the charge at around 14 bars. It often takes a number of attempts, with the car giving me a Remote Error message before it finally "takes", both with entering zero into the ON time and then the ON->OFF time. Still haven't quite pinned down the Error cause despite trying various time delays before hitting the Remote top button, although doing it in the morning after having done it the previous night seems to make it hiccup more, and it seems to happen more often using the SPX instead of Mitsu's EVSE. No matter, yesterday I gave up on the Remote...
Update 9/2/12 Traced my Remote issues to compatibility with my SPX Xpress Level 2 EVSE. It takes a few tries before the programming takes hold without an error message. The Mitsubishi (Panasonic) Level 1 EVSE works every time with the Remote.

I've gone back to the old-fashioned spring-wound Intermatic FF46H 6-Hour Spring Loaded Wall Timer, which disconnects both poles, although it might be overstressed in this application despite the slow power ramp-up of our iMiEV charger and the capacitive input which should limit turn-off peak currents. Here are its specs:
Resistive: 20 Amp, 125 VAC, 50/60 Hz, 10 Amp, 250 VAC, 50/60 Hz, 10 Amp, 277 VAC, 50/60 Hz
Tungsten: 7 Amp, 125 VAC
Motor: 1 HP, 120 VAC, 50/60 Hz, 2 HP, 240 VAC, 50/60 Hz

Inasmuch as I needed to package this timer, I decided to make it transportable and put it together with an energy consumption meter that I picked up off eBay: 230V 100A LCD DIN-rail Type Kilowatt Hour kWh Single Phas... (170850363518). It is a very simple meter that merely accumulates and displays kWHr consumed and does not reset when power is removed. This one is evidently good for both 50Hz and 60Hz.

So far, they both seem to work and I now have a definitive way of measuring my energy consumption when I take my iMiEV and charge at friends' houses using their dryer outlet. For now, I've screwed it to the wall and I'm starting to record the kWHr readings and compare them to my T.E.D. readings.

Pictured below are the two gadgets mounted in a gray box from Home Depot, with the NEMA L6-30 output connector built into the top of the gray box and the input pigtail plugging into my L6-30 wall socket (which also contains NEMA L6-20 and 6-20 sockets).

 

[GdB]

I started a new thread that seems somewhat relevant to this and a few other threads, so please excuse my promoting it.
Optimum EV Charging and Electricity Consumption Time for GHG, TOU
http://myimiev.com/forum/viewtopic.php?f=22&t=3951

 

[Adoepner]

Hi JoeS,

From my read of this thread, it looks like you've ended most of your charging sessions by cutting the mains power to your EVSE via an external timer. I also would like to not charge fully (for battery life) and wish that the Miev had a feature to allow stopping the charge (at 80%) for example.

How has your OBC fared? Have you had any failures? One of the hypotheses floating around in another thread was that abruptly ending charging sessions (not via the J1772 pilot signal) was contributing to blowing OBC capacitors.

Andrew

 

[kiev]

Andrew, i'll let Joe answer about his special charging setup.

But that was my early theory before tracing out the OBC. Something sudden has to happen to interrupt the current while in the middle of a charging session to cause the snubber capacitors to blow. Other theories were a failure of the 12V aux battery allowing the main contactors to open, OBC relay to open, etc. My latest theory is that the MCU fuse opens due to mechanical fatigue and this causes the snubber caps to blow.

The 60Hz of the 120vac Line has a period of about 17msec, and when rectified it creates a ripple frequency of 120 Hz or about 8 msec. These times are very long with respect to the clocking of the microcontroller. i now think that the controller has plenty of time to ramp down the charging current if the input AC is suddenly withdrawn. Also there are some big filter capacitors that will hold the power up long enough for a graceful shutdown without blowing the snubbers, which are on the DC output of the OBC.

 

[Adoepner]

Thanks Kiev for chiming in and your work on the OBCs. With split phase AC, the frequency is constant. Both the 120V and 240V lines are at 60Hz, with a period of 1/60 seconds (~17 msec)

Edit: If you are tracing contacts on a board, you probably know a lot more about electrical theory than I do. Are your times related to an RC/inductive decay? I'm a noob at this stuff.

A little off-topic on this thread: I have a new-to-me 2012 that has never had an OBC failure. It has only been L1 charged its whole life. Based on your MCU fuse fatigue hypothesis, should I replace my MCU fuse as a precaution? Or replace it as soon as my OBC warranty is up in a couple years My nearest dealership is a long way away … I'd rather not have to make the trip.

Andrew

 

[kiev]

You are right, i was thinking about the frequency of the rectified mains which looks like DC with a 120 Hz ripple.

How many miles on your car? if the roads are pot holed or rough then i would say get another fuse and replace it before it breaks. Same if more than 30k miles. If you don't know the previous history, then just change it and start counting from now.

Or let it go and take a chance on getting a replacement under warranty.

 

[Adoepner]

My car has 65000 km (40000 mi). I'll order an MCU fuse to have on hand. As soon as the warranty is up, it is going in. The good news is that the towing coverage included with my wife's CAA (Canadian equivalent of AAA) membership will get the miev to the nearest dealership if need be.

Thanks!

 

[JoeS]

Andrew, to answer your question, my wife and I had used two of these mechanical timers for about 5-7 years on our two i-MiEVs with no OBC issues (touch wood). Since I almost always never charge to 100% and want to stop the charging at around 12-13 bars, it became second nature to simply eyeball the charge level and crank in the time. I stopped using these timers out of concern for the OBC and now use the clunky Remote, which takes a bit more time than simply rotating a knob. I'll replace the fuse when the OBC warranty expires. I'll now go back to using at least one of these timers as my wife never got the hang of using the Remote and I sometimes find myself in the doghouse for not having charged 'her' car.

 

[pbui19]

has any one attempted to external control start/stop charging with a timer by triggering the J17xx charge plug button switch ?