Charging Delayed Start Scheduling Problem

[Dsinned]

I can't get my RAV4 EV to "schedule" a delayed departure charge properly. I set it for a 7am departure, which should be ample time to have it start sometime after midnight. But, it keeps starting waaay tooo early.

Last night it started charging at 11:17pm (2317 military time) and completed at 2:47am (0247 military time) for a total charge duration of 3 1/2 hours. That corresponds exactly with my center console setting for a standard charge. But, it must be losing track of time by starting about 4 hours earlier than necessary.

I know others are having the same problem. Anybody heard from Toyota yet as to what the problem is and how to fix it?

Obviously, this is a problem for owners who are trying to charge between midnight and 7am to capture the electric company's lowest off-peak rates. However, I usually turn in for bedtime BEFORE midnight!

 

[HD172]

When I first purchased the Rav4 I was using the upgraded Panasonic connector. I had to set my departure time to 5pm in the afternoon to get it to start charging a little after midnight. I recommend moving your departure time until it begins charging where you want it to. I also noticed that it always finishes the charge before the allotted time.

 

[Dsinned]

I recommend moving your departure time until it begins charging where you want it to. I also noticed that it always finishes the charge before the allotted time.

That seems like the only workaround we have at this point.

I wonder if this behavior could be explained by assuming the onboard charger "expects" the worse case charge duration? If the objective of the scheduler is to insure a fully depleted battery completes an extended charge before the set departure time, the actual starting time may be much earlier than necessary. As an example, the onboard charger/scheduler may ALWAYS assume the following conditions for ANY EVSE L2 charge:

Input AC Voltage = 208V
Input AC Current = 30A
Charge efficiency = 85%
Charging mode = Extended

208V * 30A * "X"hrs * 0.85 = 41.8kWh

Solving for "X", the charge duration: "X" = 41800 / (208 * 30 * 0.85) = 7.9 hrs

Of course, an EVSE L2 charger rated for and operating at 240V 32A, would complete an extended charge in significantly less time. However, the external AC Voltage and Current parameters given above may be what the "scheduler" assumes. I am totally speculating here, but if this is the case, then the scheduler initiates charging ~8 hours before the set departure time (7am), in order to GUARANTEE on time completion.

If this is how it works, that would contribute to very noticeable inaccuracies in the scheduler's behavior. I do not know anything about the J1772 standard, but if these parameters are not specified in control signals to the car thru the charge port connector, the car's onboard charger would have to make some arbitrary assumptions based on worse case conditions, greatly affecting charge completion times.

Comments?

 

[TonyWilliams]

I do not know anything about the J1772 standard, but if these parameters are not specified in control signals to the car thru the charge port connector, the car's onboard charger would have to make some arbitrary assumptions based on worse case conditions, greatly affecting charge completion times.

Comments?

J1772 is easy. The 3 big pins are 120v/120v (or neutral)/Ground, and the 2 smaller pins are communication/control pins. The vehicle's "proximity" pin just reads the resistance value in the handle of the J1772 to confirm it is connected (about 170 ohms normally to 480 ohms with the disconnect button pushed). The EVSE doesn't even normally see this value. Simple. Note: my Clipper Creek doesn't need it, so this conductor is just capped off inside the EVSE.

The other "pilot" pin sends a 12v DC signal until it is connected, then it drops to +9v and -12v in a 1hz square wave signal. The width of the signal's 9v portion indicates how many amps to provide. When it starts charging, it drops to +6/-12v.

I don't believe it can possibly know the voltage supplied until current starts flowing. Therefore, it's a bit hard to know the actual charge time until it actually starts. (I could be wrong on this).

On the start times, you could just use a timer on the charger and turn the timer off on the Rav4. My Clipper Creek has a pin specifically for this. Of course, I have to put on a timer on the pin (open is ON, grounded is OFF). That way, it will only come on at midnight to 5am, no matter what, which is my "super off peak" at 7.7 cents/kWh.

I have never seen a Leviton unit up close, and don't know what features it may have, but I would imagine this same timer capability exists. It's typically used for part time EVSE's in commercial use, so the it could automatically be disabled when the business is closed, for example.

 

[TeCKis300]

I'm frustrated with this as well.

I have a really simple charging schedule: Sat-Sun charge only depart at 5AM.

I do notice that it generally starts/finishes rather early based on my email alerts (~12:50 - ~3:10AM), which typically is not a problem as that's within my super off peak hours (12-5AM). This is with the typical ~40 miles range left on the GoM.

This past Sun, we had only 20 miles left on the GoM.

My email alerts tells me it started at 9:34 PM - 1:47 PM. That's a lot of power outside of my super off peak rates. GRRRR!

And this is on the recommended Leviton 40 amp EVSE.

There's some seriously flawed logic in the scheduling system that manages the charge timers.

 

[TonyWilliams]

And this is on the recommended Leviton 40 amp EVSE.

There's some seriously flawed logic in the scheduling system that manages the charge timers.

Put a simple timer on that EVSE; it will pay for itself.

 

[TeCKis300]

And this is on the recommended Leviton 40 amp EVSE.

There's some seriously flawed logic in the scheduling system that manages the charge timers.

Put a simple timer on that EVSE; it will pay for itself.

I can and will if I must.

But that won't help everyone else with likely the same issue. Nor will it give Toyota the right feedback to improve their product. I paid good money to have a working vehicle that I should not have to hack to make work.

But point taken, I have options.

 

[Dsinned]

Put a simple timer on that EVSE; it will pay for itself.

I don't think this is a practical thng to do because most of us are using "Level 2" EVSEs, which operate at 240Vac. Simple (cheap) AC timers are only for use on 120V outlets!

 

[Bassman]

Deleted

 

[Bassman]

I can't get my RAV4 EV to "schedule" a delayed departure charge properly. I set it for a 7am departure, which should be ample time to have it start sometime after midnight. But, it keeps starting waaay tooo early.

Last night it started charging at 11:17pm (2317 military time) and completed at 2:47am (0247 military time) for a total charge duration of 3 1/2 hours. That corresponds exactly with my center console setting for a standard charge. But, it must be losing track of time by starting about 4 hours earlier than necessary.

I know others are having the same problem. Anybody heard from Toyota yet as to what the problem is and how to fix it?

Obviously, this is a problem for owners who are trying to charge between midnight and 7am to capture the electric company's lowest off-peak rates. However, I usually turn in for bedtime BEFORE midnight!

Ditto. The Toyota timer sucks! I set my departure time to 5:30 AM and with the battery already at 45%, it wants to start at 9:00pm, 3 hours before my off-peak time starts. Our LEAF timer is so much easier, just set the time when you want it on and off. Easy peasy. The departure timer would be okay if it worked right, but it doesn't.
:roll:

 

[TonyWilliams]

Put a simple timer on that EVSE; it will pay for itself.

I don't think this is a practical thng to do because most of us are using "Level 2" EVSEs, which operate at 240Vac. Simple (cheap) AC timers are only for use on 120V outlets!

First, you could use a 120v timer if you pull a neutral wire to the EVSE.

Lowes has a simple one for the 240 volt pools and spas. About $50.

It just opens and closes a contact, so you can wire it into the proximity lead with a resistor. Clipper Creeks have an actual lead for a timer.

Promity sensor resistance with and without the button pushed on the J1772 handle:

 

[Stan]

Here is the timer/relay that I bought. It costs < $10 is powered from 240vac, and has a "dry" relay contact output which means it contains a relay with both sides accessible by connections (and neither side tied to AC).

Just wire the timer to your EVSE, set it to enable the EVSE from midnight to 7am every day (or whenever your time-of-use cheap rates are in place), and let it do the timing instead of relying on the car itself.

In my case I've connected the relay output to ground an input on a CS-60 EVSE, which disables charging.

On EVSE's other than Clipper-Creek units, the relay could alternatively be used to open ( i.e. disconnect) the "Pilot" wire from the EVSE to the car when you don't want to charge. One would do this by opening the EVSE and connecting the "Pilot" wire from the J1772 cable through the relay on the timer and then to the EVSE. Charging would be disabled when the relay is open. As others have noted elsewhere, the "Proximity" wire isn't passed to the EVSE by some J1772 cables so it is most convenient to disable charging by using the timer relay to disconnect the "Pilot" wire.

The fact that the timer is powered by 240vac is convenient as it can be powered by the same circuit as the EVSE and doesn't require pulling a neutral. Put inline fuses in both power wires to the timer.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170971033025
or
http://www.amazon.com/Amico-Digital-Programmable-Electronic-220-240V/dp/B008X1FWEC

 

[rcrisp123]

I have the same problem......I am frustrated!!!!

 

[rcrisp123]

Is this problem more prevalent at the end of the month??? Mine was working fine for the whole month but in the last three days, it refuses to follow the timer.

 

[smkettner]

Has the timer been updated for 2014?

I set my departure time for 7a and charging starts after midnight and is done by 6a when I am down 2 to 10 bars. Lower than 10 bars I think I would need to override and extend the departure by 1 to 3 hours depending on how low.

I have started a spread sheet of start and stop times and it seems fairly consistent based on bars down. 30 amp Schneider EVSE.

 

[fooljoe]

I haven't seen any changes whatsoever in the '14s. For a better timer option try RavCharge.

 

[vips]

After the latest firmware updates from Toyota and Tesla last week, I am now able to my EVSE scheduled charge times control the start and end times of charging.
This was not the case earlier. Now the car starts charging exactly at 12:15 am, in my case, everyday.

 

[miimura]

After the latest firmware updates from Toyota and Tesla last week, I am now able to my EVSE scheduled charge times control the start and end times of charging.
This was not the case earlier. Now the car starts charging exactly at 12:15 am, in my case, everyday.

Which EVSE are you using?

 

[smkettner]

After the latest firmware updates from Toyota and Tesla last week, I am now able to my EVSE scheduled charge times control the start and end times of charging.
This was not the case earlier. Now the car starts charging exactly at 12:15 am, in my case, everyday.

How is your the RAV timer set?

 

[vips]

No schedule. Charge immediately.