Better charging controls

[Quixotix]

I agree that the delayed charging with the remote is hokey. But, I have a possible explanation for why it is that way.

First, I highly suspect that delayed charging function was added late in the design to try to match what the Leaf has.

Second, note that the while the timing is set by the remote, but the car keeps track of when to start and/or stop charging. That is, the remote only "talks" to the car when you press the buttons on the remote. It does not send a signal to the car when the time to start/stop charging actually occurs (if the remote were to try to send the signal at the actual start/stop time, you might have set it somewhere where the signal was blocked, so the message wouldn't get through and your car wouldn't charge).

For the system the way it is, the on-board charge controller doesn't need a clock, only a timer. And, the timer doesn't even need to be very accurate. However, to start charging at 12:30 pm every day, the charge controller would need a clock. The way it is now, it only needs to know when approximately when the set number of hours have passed.

I suspect that their charge controller was already designed, or mostly designed, when the engineers got the requirement to have delayed charging. The charging controller undoubtedly already had circuits in it that could count time, but maybe not to the accuracy we expect of a clock. Mitsubishi probably decided that adding a clock or, the user interface to set the clock, would take too long or be too expensive. Getting the time from the dash clock (radio) seems like an obvious solution, but getting two pieces of electronics to talk to each other when they weren't designed to do that may not be an easy task. Add in that these components may be being designed or produced under contract by other companies, and changes can be really hard to implement late in the game.

[jray3]

[quote="jjlink"]I assume you don't have to use the remote to initiate the charging cycle, correct? Does just plunging in the car to a charge station cause it to start charging?

Yep, just plug'er in, and you'll hear the contactor clunk within the charging station (EVSE), followed immediately by a blower purge of the iMiEV battery compartment. The lithium batts shouldn't be generating any hydrogen, but it's a nice safety step and gives audible confirmation that charging has commenced. I'm finding m i self opening the doors with annoying frequency to check the SOC because the key fob only has a 3 bar indicator rather than 16 bars or a NUMBER , and the i doesn't have status LEDs on the top of the dash, like a Leaf.

[JoeS]

As the present owner of a number of EVs, I have a good feel for the time required to recharge each one based on the number of miles driven (and who drove them - my wife's a featherfoot whereas I'm a leadfoot unless I need to hypermile). I use mechanical timers to shut off the input power about when I think the car's fully charged, despite having fairly intelligent chargers and BMS.

I'm on Time-Of-Use metering, which means that between noon and 6pm my rates are extremely high (~35cents/kWh) whereas between 6pm and noon they're quite low (~9cents/kWh).

I would like to put my iMiEV's EVSE on a power input timer, set to be OFF between noon and 6pm.

Since I don't have an "i" yet and can't access the manual online, I'd appreciate it if someone could answer the following:

1. Can I preset the iMiEV's timer to charge for a preset amount of time?

2. Can I leave the EVSE input power off and will the "i" automatically commence charging when power is applied to the EVSE?

3. When charging commences, I will normally want to let it charge to what I feel is about the 80% point and would like to have pre-set a timer to do this. Feasible to do with the iMiEV's built-in timer?

My fallback is to simply do it the old-fashioned way: go back into the garage after 6pm and activate vehicle charging using a manual timer.

Any hints or suggestions from present owners?

jjlink: how did that Sunleaves timer work out?

Thank you.

[jjlink]

JoeS: The Sunleaves timer works just fine turning on/off my Leviton L2 EVSE daily. However I don't have the car yet. They say its still on the boat. I suspect the timer will work fine.

Maybe someone could download the user manual for the 'i' for us.

[jray3]

Joe, I'll say Yes, Yes, and not really...
The charger will start up whether J1772 or the EVSE power supply is connected first, or if a tripped breaker is switched back on, so external timers should work just fine.
I don't have any info about how high the onboard charger takes the batteries when left plugged in for extended periods, or whether there's a periodic conditioning/balancing function that can be affected by the user.
I've experienced a couple of premature charging shutdowns. Have ruled out temperature and SOC as factors, and may have just caused it by fooling around with the remote!
The remote is hokey, but very useful. The first couple of times I tried to preheat the car, it got lukewarm and then shut off, but this morning, with proper instruction, the windshield got 100% clear and the car was toasty after less than 30 minutes, and this was after a 22 degree night with heavy frost!
-Jay

[JoeS]

Hi jjlink and jray3, thanks for the inputs. Nice to know that I can always time my charging externally without having some weird interlocks prevent that.

My own situation is that I live in the hills and invariably start every trip with a three-mile downgrade, and thus my desire to terminate charging prematurely (besides, Lithiums don't like to sit at full charge for any extended period of time). Since we don't have the option of programming the charger to stop at 80% charge (like the Leaf), I'll be stopping my charger early as I want to maximize my battery life.

Wonderful about being able to pre-condition the car while it's still plugged in. Hope I get my car in time to try it out this winter...

[jray3]

Woo-Hoo; solving my charger confusion
Now I'm an early adopter type, (early Palm user, Blackberry picker, managed to use a Windows Mobile device when forced to, love my iPhone), but this remote is shall we say, non-intuitive. Turns out that the little icon of an unplugged electrical cord actually means that the car is charging! Seriously though, I now attribute my few problematic charging sessions to user interference. That is, if you plug the car in, it starts charging, but then if you set the "ON timer", it will turn off the charger.
Microsoft must have inspired an iMiEV engineer. This is just like selecting "Start" to shut down your computer...
Every time I send any timer command, charging stops for a couple of seconds while the car considers it's options. It appears to restart every time it's told to, but this will take further study. Read y'all's manuals carefully!

[rickmaz]

Since I also live 1400 feet above Hilo, I like to set the timer so the car doesn't fully charge. One reason is that there is hardly any braking provided by the regen system if the battery is full, and you have to use friction brakes on the way down. Also, I like to be able to recover some of the energy used in coming home UP the hill. The key fob timer function definitely takes some trial and error. For my normal driving...I can take four trips into town and then do a 2.5 hour Level2 charge and that leaves me with 14 bars charged.

One thing that could be improved on the next version of the car, is to be able to view the level-of-charge gauge without having to open the car door! Or have the key fob show a more accurate charge level, than just three bars.

Also, guys the only "manual" that is posted online for the 'i' on the owner's site, is the "warranty manual". The other manuals are not posted online for download or viewing. Otherwise I'd help out.

[JoeS]

Is the charging linear or does it taper off (i.e., take more time per bar) as it approaches full? Without better external visuals, I'm hoping we'll all quickly get a feel for this and won't need to take a peek inside.

[jjlink]

I got my 'i' today and the Sunleaves timer works just fine turning on/off my Leviton L2 EVSE and charging the car.