RavCharge, a solution to charge timer and entune woes

[AltPowr]

Quick question on RavCharge. I've only had the car a few days, so still trying to figure out all the numbers - Tesla makes it so easy. Anyway, See my picture below. I did an extended charge because we are taking a long drive today and since I have no time constraints I want to experiment with how far I can go. So I've reset my trip counter for an actual measurement when I'm done. But after last nights charge, I see in RavCharge "0:53 to extended charge @...". That to me seems to state that I need another 53 minutes of charge for an extended charge. However, on the entunes screen you can see it's complete and has the Extended Charge label showing. I did manually start charging from RavCharge, I heard and saw the EVSE kick on, then it stopped after a few minutes and I got both amber LEDs lit solid in the back window. So I assume it really is fully charged (oh and the dash does popup the extended charge warning when turning off the car).

So what is the 53 min talking about on the RavCharge screen?

 

[fooljoe]

This is just a limitation of Entune that RavCharge is stuck with. RavCharge pulls state of charge information from Entune, and that information comes as 0-100% SOC, where 100% is a full normal charge. Note that the Entune app has this same limitation, as that battery picture represents a full normal charge, and there's no little "extra" battery space for an extended charge. And the car itself also doesn't show any "extra bars" beyond a normal charge either. Don't ask me why Toyota did it this way, but it is what it is. I expect that soon we'll have some add-on apps/accessories available to tap into the CAN bus and at least give you that SOC information when you're in the car.

Since RavCharge can't know what your SOC is between a full normal and full extended charge, all the calculations it does are based on that 100% SOC figure, and the 53 minutes you see indicate how long it would take to get from full normal to full extended charge. The "entune range" will update, however, so until you get below 100% of normal you can use that as an indication of where you're at.

 

[Dsinned]

I just tried the new SMS commands from my iPhone and it WORKS! I had no problem setting it up with RAVCHARGE. I wasn't plugged in at the time, so the only command that works is "Status". Just out of curiosity, I also tried the "Climate" command, which of course failed, because the car was still unplugged. I almost never use remote climate control, because the car is usually unplugged most of the time. Same for my VOLT. Nice feature, but just don't need it.

As an aside, I have 49 days left on my RAVCHARGE subscription. Is the renewal for a second year going to another $39?

I have recently reconfigured and optimized my "scheduled" charging regime, so that I don't actually need RAVCHARGE (or EnTUnes), but I may still renew anyway. I now have a VERY reliable way to do scheduled charging using my JuiceBox. It has a built in "timer" of its own, and with the LCD and Remote Key Fob options, scheduling a charge is very easy to do. I don't use the scheduler in either of my cars anymore. Instead, I have them preset to "CHARGE IMMEDIATE" but nothing happens when I plug in. This is because I have my JB timer preset to activate only at midnight, seven days a week. If I really want an immediate charge, the JB timer can be overridden at will with its own "charge immediate" command which works flawlessly either way!

 

[Kohler Controller]

Fooljoe,
Since we know that standard charge enables 35kWh to be used, and extended mode enables 41.8kWh to be used (when new), couldn't you adjust the 100% reading from EnTunes to show 84% SOC on RAVCharge instead? (35/41.8=0.837) Since EnTunes tells you when Extended Charge is enabled, then RavCharge could show the estimated state of charge between the two modes. If RavCharge knows the rate at which the vehicle is being charged, then it can calculate the SOC between 84%-100% (41.8-35= 6.8kWh to count down) when EnTunes is in blind mode.

Example: Car set to Standard Charge mode. EnTune tracks it reporting 100% when finished, while RavCharge tracks it by subtracting 16% from EnTune's value and reports 84% when finished.

If car is set for extended mode, RavCharge now knows that once EnTune reports 100%, to track and report the rest of the SOC based on the charging power. If 6.6kW is flowing, RavCharge can update the SOC every 15 minutes adding 4% to the SOC until EnTune reports Charge Complete, which RavCharge can then report 100%.

 

[fooljoe]

I just tried the new SMS commands from my iPhone and it WORKS! I had no problem setting it up with RAVCHARGE. I wasn't plugged in at the time, so the only command that works is "Status". Just out of curiosity, I also tried the "Climate" command, which of course failed, because the car was still unplugged. I almost never use remote climate control, because the car is usually unplugged most of the time. Same for my VOLT. Nice feature, but just don't need it.

As an aside, I have 49 days left on my RAVCHARGE subscription. Is the renewal for a second year going to another $39?

I have recently reconfigured and optimized my "scheduled" charging regime, so that I don't actually need RAVCHARGE (or EnTUnes), but I may still renew anyway. I now have a VERY reliable way to do scheduled charging using my JuiceBox. It has a built in "timer" of its own, and with the LCD and Remote Key Fob options, scheduling a charge is very easy to do. I don't use the scheduler in either of my cars anymore. Instead, I have them preset to "CHARGE IMMEDIATE" but nothing happens when I plug in. This is because I have my JB timer preset to activate only at midnight, seven days a week. If I really want an immediate charge, the JB timer can be overridden at will with its own "charge immediate" command which works flawlessly either way!

The climate command works when unplugged as well, as long as you have a high enough SOC. I always use it when unplugged, myself.

As far as timers, the EVSE timer solution is definitely an option, but I thought I read elsewhere that if the delay is too long in between plugging in (the "dead" plug) and your timer firing, your car will "go to sleep" and not awake to charge.

And yes, RavCharge remains $39/car/year. Thanks for your support!

 

[fooljoe]

Fooljoe,
Since we know that standard charge enables 35kWh to be used, and extended mode enables 41.8kWh to be used (when new), couldn't you adjust the 100% reading from EnTunes to show 84% SOC on RAVCharge instead? (35/41.8=0.837) Since EnTunes tells you when Extended Charge is enabled, then RavCharge could show the estimated state of charge between the two modes. If RavCharge knows the rate at which the vehicle is being charged, then it can calculate the SOC between 84%-100% (41.8-35= 6.8kWh to count down) when EnTunes is in blind mode.

Example: Car set to Standard Charge mode. EnTune tracks it reporting 100% when finished, while RavCharge tracks it by subtracting 16% from EnTune's value and reports 84% when finished.

If car is set for extended mode, RavCharge now knows that once EnTune reports 100%, to track and report the rest of the SOC based on the charging power. If 6.6kW is flowing, RavCharge can update the SOC every 15 minutes adding 4% to the SOC until EnTune reports Charge Complete, which RavCharge can then report 100%.

The SOC% reading from Entune is always based on the normal charge scale, even if your car is in Extended mode. I could conceivably read that the car is in extended mode and deduce that you have 41.8 kwh when fully charged, but there are a couple problems with this. First, you could have a full normal charge mode and switch to extended charge mode - RavCharge would then see 100% and extended charge, but you'd only have 35 kwh. Next, you could have a full extended charge and switch extended mode off, in which case RavCharge would see 100% and normal mode, but you'd actually have 41.8 kwh. Lastly, you could be in between 35 and 41.8 kwh, and it'll still read 100%, so there's no help there.

Believe me, I've thought about this plenty, and there's no way to get any SOC info above 100% of normal from Entune, except to try to infer it from the GOM. And the GOM is, well, the GOM...

The best I can do is add the extra time to charge for extended charge mode, to get a reliable estimate of that (assuming you're not starting somewhere above 100% of normal, and that's what I do. And I give you an estimate of your rate of charge above 100% of normal that's based on the GOM.

 

[Dsinned]

To further complicate such a calculation is the "taper" that results nearing the end of an extended charge and apparently the taper itself is non-linear depending on the charging rate. That is, presumably taper activation triggers earlier the faster the charging rate.

Btw, thanks for the tip on remote climate control. I forgot that above 50% SOC, it should still work even unplugged.

 

[yblaser]

Love the SMS interface. Shortcuts so I could text just 1, 2, 3, or 4 for the various commands or requests would be great.

 

[fooljoe]

Love the SMS interface. Shortcuts so I could text just 1, 2, 3, or 4 for the various commands or requests would be great.

Great idea. In the spirit of laziness, however, I went with letters instead of numbers, as switching to numbers on the iPhone involves an extra tap. So it's a for climate (think air), b for status (battery), and c for charge. Either upper or lowercase works, so don't worry about that.

 

[AltPowr]

Since RavCharge can't know what your SOC is between a full normal and full extended charge, all the calculations it does are based on that 100% SOC figure, and the 53 minutes you see indicate how long it would take to get from full normal to full extended charge. The "entune range" will update, however, so until you get below 100% of normal you can use that as an indication of where you're at.

OK, thanks, I get it. Just a suggestion, but if the standard charge is at 100% and extended charge is selected, how about changing that line to display simply the following since the number of minutes here will almost always be wrong:
Extended Charge selected

If, however the standard charge is anything less than 100% (and extended charge is selected), then put exactly what you have now:
1:31 to extended charge @

Basically, this shows that we don't have the ability to show the SOC any higher than 100% standard charge.

 

[fooljoe]

OK, thanks, I get it. Just a suggestion, but if the standard charge is at 100% and extended charge is selected, how about changing that line to display simply the following since the number of minutes here will almost always be wrong:
Extended Charge selected

I like the spirit of this idea. However, I could envision someone charging to full in normal mode, then deciding to switch to extended mode to top off, and being interested in how long that would take with a given voltage/amperage (I know I've been there), so I wouldn't want to just remove the calculated time-to-charge value.

Here's what I did (at least I think I did, as I haven't really had the occasion to test it yet): If you're at 100% with extended charge selected, it'll say the same as it does now, i.e. "hh:mm to extended charge", but add "(from 100% of normal)" to that before the "@ v volts a amps".

 

[AltPowr]

Here's what I did (at least I think I did, as I haven't really had the occasion to test it yet): If you're at 100% with extended charge selected, it'll say the same as it does now, i.e. "hh:mm to extended charge", but add "(from 100% of normal)" to that before the "@ v volts a amps".

Now that I know, it won't be a problem for me, so whatever you change is perfectly fine. Do you have enough room on the line for all those characters without changing font size? I don't think that would fit on my iPhone. But in any case, it still shows a number of minutes to charge which is incorrect 99% of the time. I absolutely get what you mean - that is "potentially" how much time it would take, and I agree that allowing us to move around the sliders to figure out how much time we need is smart. It really sucks that we can't get the right data.

 

[fooljoe]

I just implemented a new feature: Early charge protection. Set the time before which you don't want the car to start charges, and the amps supplied by your EVSE, and RavCharge will periodically check to see if the car's estimated start time will be earlier than your "not before" time, and will adjust your departure time accordingly. This is still very much "in beta", so try it out and let me know how it goes!

 

[miimura]

You seem to be assuming 240V. So, if you happened to be using 208V 30A, you would set 26A in the ECP EVSE amps control? Also, that control only goes down to 21A. It would be nice if you could help compensate for the <20A bug too.

 

[fooljoe]

You seem to be assuming 240V. So, if you happened to be using 208V 30A, you would set 26A in the ECP EVSE amps control?

No, you should set 30A. The voltage doesn't matter to the car! (Which is a big reason why its timer's so terrible.) The car calculates your time to charge based on your amperage alone: For anything greater than 20 amps the car does its calculations assuming ~140V. And for this feature, RavCharge doesn't care how long your charge will actually take - it's only concerned with making sure the car's screwy timer doesn't start too early.

Also, that control only goes down to 21A. It would be nice if you could help compensate for the <20A bug too.

I would like to add support for <=20A EVSEs as well, which the car assumes are L1 (Toyota would say it's not a bug, it's a feature! :lol However, I need to do some testing to determine what voltage exactly the car assumes L1 means, whether it uses a different efficiency factor, and whether it takes into account amperage on L1 or does something silly like figure all L1 EVSEs will charge at 12A despite the pilot signal. Also, I'd run into the problem of departure times sometimes needing to be pushed back by up to a whole day or possibly even more, which could lead to some weird results.

 

[fooljoe]

Also, that control only goes down to 21A. It would be nice if you could help compensate for the <20A bug too.

Ok, I went ahead and did some testing to figure out the car's L1 calculations, so now I've updated it to work with <=20 (down to 6) EVSE amps. I am limiting the maximum amount of time that it will push back the departure time to 10 hours for now, however, to avoid "strange" conditions.

 

[miimura]

Also, that control only goes down to 21A. It would be nice if you could help compensate for the <20A bug too.

Ok, I went ahead and did some testing to figure out the car's L1 calculations, so now I've updated it to work with <=20 (down to 6) EVSE amps. I am limiting the maximum amount of time that it will push back the departure time to 10 hours for now, however, to avoid "strange" conditions.

That's great. Did you find anything unexpected in the way the car calculates things for 20 amps and below? Does it really assume 120V when the pilot is <=20A, no matter what the actual voltage is?

Of course, when you have an EVSE at or below 20A, even on 240V, the user still needs to check how long the charge will actually take and decide if they want to use the ECP at all on that day.

 

[fooljoe]

That's great. Did you find anything unexpected in the way the car calculates things for 20 amps and below? Does it really assume 120V when the pilot is <=20A, no matter what the actual voltage is?

Remember the car has no way of knowing the actual line voltage because it doesn't momentarily close the EVSE relays like other EVs do when plugging in and in timer mode, so yes, it really does just assume one voltage level for <=20A and another for 21A+.

If we assume 80% efficiency in either case, my testing indicates the car's time to charge calculations assume ~140V with a 21A or greater pilot signal, and ~70V with a 20A or less pilot. Of course the efficiency will actually be less on L1 (I measured 66% doing a 115V/16A charge yesterday), so I guess the assumed voltage is probably something a little higher - but of course it's only the product of voltage and efficiency that matters to the calculation, not the individual numbers. So the car's overestimation of charging time is not just limited to L2 charging, but percentage-wise the error will usually be a little less on L1.

As an aside, based on this testing I did actually adjust RavCharge's (actual) time to charge calculator to use a lower efficiency for L1 charging, and I'm looking into doing some more testing to determine whether I should maybe use some sort of continuous function for efficiency based on either the total power or just voltage. For example, it'd be interesting to know if the efficiency is the same charging at 240V/10A as it is at 120V/20A, and if it's the same at 240V/40A as it is at 240V/30A, etc. If anyone has done or wants to do some testing of their own let me know!

Of course, when you have an EVSE at or below 20A, even on 240V, the user still needs to check how long the charge will actually take and decide if they want to use the ECP at all on that day.

Yeah, with lower power charging it's quite likely that your charging will take longer than the typical 6-7 hour low rate window, so even if ECP can keep your charge from starting before the window starts, there's certainly no guarantee that it'll finish before the window's over, or even before you need to unplug and drive in the morning, for that matter.

I seriously doubt there will be many people on TOU that charge on L1 or very low power L2, anyway, but I suppose somebody who doesn't drive much could make use of this.

 

[DevinL]

Of course, when you have an EVSE at or below 20A, even on 240V, the user still needs to check how long the charge will actually take and decide if they want to use the ECP at all on that day.

Yeah, with lower power charging it's quite likely that your charging will take longer than the typical 6-7 hour low rate window, so even if ECP can keep your charge from starting before the window starts, there's certainly no guarantee that it'll finish before the window's over, or even before you need to unplug and drive in the morning, for that matter.

I seriously doubt there will be many people on TOU that charge on L1 or very low power L2, anyway, but I suppose somebody who doesn't drive much could make use of this.

Huzzah! My charging pattern has just changed to adapt to my new semester which started today. As such I will indeed be making much use of this new Ravcharge feature. It's easier to park the RAV4 in my garage on the side with the 20A/240V circuit (OpenEVSE set to 16A) in the interest of household harmony. I just got home and the car decided to start charging up from 20.6kWh SOC despite my 6AM charge deadline.

My current schedule has me start the day at 7:20A in downtown LA, return home at about 9A, then leave again in the middle of the day for a few hours (but this time to Woodland Hills). Then I come home in the afternoon and have night classes (again in Woodland Hills) some days in the week. The days with the night classes are not so much of an issue since I can avoid plugging in until after, but on the days without nights I don't want it to start charging right away when I get home. Since I'll never really be using more than 20kWh in the course of this (today I only used 14.4kWh), the 16A will do fine.

Do I need to change the timers in the car once I've set up ECP in RavCharge? Also, is there an option to have ECP only enabled for certain days like the start timers?

 

[fooljoe]

My current schedule has me start the day at 7:20A in downtown LA, return home at about 9A, then leave again in the middle of the day for a few hours (but this time to Woodland Hills). Then I come home in the afternoon and have night classes (again in Woodland Hills) some days in the week. The days with the night classes are not so much of an issue since I can avoid plugging in until after, but on the days without nights I don't want it to start charging right away when I get home. Since I'll never really be using more than 20kWh in the course of this (today I only used 14.4kWh), the 16A will do fine.

Do I need to change the timers in the car once I've set up ECP in RavCharge? Also, is there an option to have ECP only enabled for certain days like the start timers?

I wouldn't recommend a change to your departure timer based on switching ECP on, but I would recommend changing your departure timer (significantly) based on your new schedule/EVSE settings. The idea is you program your departure timer to be late enough so it doesn't start too early for your ordinary usage pattern, but you leave ECP on to catch those times when you take the battery way down and/or want to do an extended charge, so your usual departure timer wouldn't be late enough.

In your case with a 16A EVSE, you have to account for the car thinking that you're charging on 120V, so you've got to move your departure timer wayyyy back. When the car sees a 16A pilot it assumes you will charge at ~900W (at the pack not the wall.) So if you expect to be using up to 20 kwh (i.e. going down to ~43% SOC), that means the car thinks it'll take you about 22.5 hours to charge (including its 20 minute extra buffer)! So you'd need to set your car's departure timer to 10:30 pm, while if you start your charges at midnight they'll actually finish around 6:40 am. :roll:

Then you can set ECP to midnight to account for days when you might use more than 20kwh, but of course if you're trying to charge from midnight to 6am you won't be making that anyway, since your actual charge rate is about 3kw. Setting ECP to 11pm might work out better. And of course have your RavCharge start timer set for around midnight as well to account for days where you'll use fewer kwh, and for days when the car's timer just up and decides not to work.

Unfortunately having your departure timer set so late means that you'll probably get home and plug in before you've passed the departure time, in which case the car will probably start charging immediately. So to account for that you'd want to just have your departure timer set for 1 day a week (when you get home late I suppose) and rely on RavCharge to start your charges otherwise. ECP will serve to make sure that your charges don't start too early on that day. You could also possibly use an EVSE timer to make sure your EVSE isn't turned on until after the departure time has passed. Living with a Rav and a low power EVSE ain't easy!

I'll think about adding the option of selecting different days for ECP, but it would be a rather extensive effort to change it from the way I have it set up, and I'm not sure I see the value of it given my idea of how ECP is best exploited.