RavCharge, a solution to charge timer and entune woes

[miimura]

Nope, no pre-conditioning was selected/scheduled in the car or Ravcharge. This behavior is ALWAYS the same for EVERY charge. Other than the bulk charge itself, this additional "charging activity" is the ONLY other time the charging station is activated.

I have documented this unexpected "event" numerous times here on this forum, and by way of pure speculation, have referred to it as an "equalization" charge, "topping off" charge, "balancing" charge, but in reality, I have no idea what it is, or why it occurs when it does.

My car does this too, regardless of ambient temp. Always finishes 7 minutes after the scheduled departure. No climate is scheduled - the car is set to charge only.

 

[waidy]

Would someone tell me what is the difference between the buttons "Refresh" and "Update now"? If they are the same, which button is faster ?

 

[fooljoe]

Would someone tell me what is the difference between the buttons "Refresh" and "Update now"? If they are the same, which button is faster ?

'Refresh' is just to reload the webpage, so you're not looking at stale information - it will show you the information last sent by the car to Entune. The car sends this information on its own every time you turn it off, and when charges start and complete, and when you run climate remotely. 'Update now' pings the car for the latest information. You would generally do this to get an update while you're driving or charging.

 

[Dsinned]

Joe, I was a bit perplexed by the difference between these two as well. Of course, it often appears that the last time stamp on the main screen is out of sync with actual time, which I think is another reason why RavCharge users may get confused. Could you combine these two "buttons" in to one called, "Refresh & Sync w/Entunes", so that RavCharge reflects actual time? You could also possibly do a re-sync automatically every time the user logs in to RavCharge, but still keep the Sync button in case some users just stay logged in all the time.

 

[Dsinned]

Joe, FWIW, one more thing I have noticed about Ravcharge is that when I "Update now", it seems to revert to a previous timestamp on the home screen. Repeated attempts to update do not override that old timestamp. I am using IE V9 on a Vista laptop PC.

 

[fooljoe]

Joe, I was a bit perplexed by the difference between these two as well. Of course, it often appears that the last time stamp on the main screen is out of sync with actual time, which I think is another reason why RavCharge users may get confused. Could you combine these two "buttons" in to one called, "Refresh & Sync w/Entunes", so that RavCharge reflects actual time? You could also possibly do a re-sync automatically every time the user logs in to RavCharge, but still keep the Sync button in case some users just stay logged in all the time.

To put it in other terms, 'Refresh' is a sync with Entune, while 'Update now' tells Entune to sync with the car. And a refresh does happen every time you log in.

Joe, FWIW, one more thing I have noticed about Ravcharge is that when I "Update now", it seems to revert to a previous timestamp on the home screen. Repeated attempts to update do not override that old timestamp. I am using IE V9 on a Vista laptop PC.

The timestamp displayed by RavCharge is a value taken straight from Entune, just like the SOC%, and the Entune range, and whether your car's plugged in, etc. You'll see the same time in the Enutune app. In my experience, after a successful 'Update now' the timestamp will always be the current time, while after a 'Refresh' the timestamp will always be the time I last parked or started/completed a charge or climate operation. I can't imagine how you could ever see a timestamp going backwards, but send me some screenshots and I'll do what I can to decipher what could be going on.

Not that it's causing this problem (although it could be), but I'll reiterate that any version of IE is not on my "recommended browser list." I recommend the latest version of Chrome on the desktop or most mobile browsers. I do most of my testing in iOS Safari. On questionable browsers especially, it's a good idea to do a 'Refresh' after doing an 'Update now,' as 'Refresh' plugs in the Entune info on my server before sending the page to your browser, while 'Update now' relies on your browser to plug in the latest values without reloading the whole page.

 

[TonyWilliams]

I drove to turtle yesterday, and I wanted the minimum charge to get home on 120 volts. It was about 7 miles.

After almost two hours, the dash still showed no fuel bars, "LO", and the turtle. But, RavCharge pulled through to ensure that the car was getting charged, and that the range was enough to get me home.

Great product.

 

[fooljoe]

I drove to turtle yesterday, and I wanted the minimum charge to get home on 120 volts. It was about 7 miles.

After almost two hours, the dash still showed no fuel bars, "LO", and the turtle. But, RavCharge pulled through to ensure that the car was getting charged, and that the range was enough to get me home.

Great product.

Awesome Tony! I'm glad that the increase in resolution RavCharge provides over Entune and the dash instrumentation helped you with your charge planning. Did you happen to notice what your SOC% reading was in RavCharge after you hit turtle? Did you get it all the way down to 0?

 

[Dsinned]

Depending on Tony's driving efficiency, a two hour charge at 120V, probably would yield 5 to 7 miles of additional range. This may be insufficient to relight at least one segment on the Range Gauge (GoM). One segment corresponds to ~2kWh, perhaps a bit more, assuming the gradients on the range gauge change in a linear fashion. Although, like most fuel gauges in ICE cars, the fuel tank gauge is typically conservative as the gauge reaches its lowest level.

I too, like Joe, would be very interested to know what Ravcharge indicated after Tony's two hour charge, not only the SoC%, but but also "range" and the amount of battery capacity (kWh) after such a little amount of recharging. Also, what did Ravcharge indicate in terms of Entunes range, if any?

 

[waidy]

On the "unplugged" screen (1st tab, or the default screen when you login) it gives me information "Approximate charge: 9.8 kwh" (very first line). I am curious of how this information (9.8 kWh in this case) is generated. I assume it represents the approximate SOC in kWh.

 

[fooljoe]

On the "unplugged" screen (1st tab, or the default screen when you login) it gives me information "Approximate charge: 9.8 kwh" (very first line). I am curious of how this information (9.8 kWh in this case) is generated. I assume it represents the approximate SOC in kWh.

Your approximate charge is simply your % charge times your normal charge capacity.

Your % charge is a number from 0-100% that comes directly from Entune (but is not visible in the Entune app) and is displayed on the middle tab, and your normal charge capacity can be modified under Menu->Settings (default 35kwh.)

Assuming you haven't changed the normal charge capacity from the default, which is recommended unless you have good reason to suspect quantifiable battery degradation, then an approximate charge of 9.8 kwh means you have 28% charge.

 

[waidy]

Your % charge is a number from 0-100% that comes directly from Entune (but is not visible in the Entune app)

Great!! This is what I want to know. Thank you very much.

 

[Dsinned]

I have found that using a "normal" charge capacity of 35kWh biases Ravcharger's projected range higher compared to the range indicated by Entunes. Even if I adjust normal charge capacity down to 33.4kWh, (as some here suggest is more accurate), Ravcharger's range is still higher than Entunes (w/CC off). The logical conclusion to explain this disparity is that Entunes (and the in-car GoM Range gauge) provide a more conservative, i.e. lower reading, than actual. Unfortunately, this cannot easily be correlated to Ravcharger's prediction because of the continuous variability of driving efficiency (miles/kWh) while driving the RAV4 EV in the real world.

 

[fooljoe]

I have found that using a "normal" charge capacity of 35kWh biases Ravcharger's projected range higher compared to the range indicated by Entunes.

Just this morning, my Entune range was higher than my RavCharge range - probably because I drove very efficiently yesterday (and I had a relatively conservative estimate of 3.5 miles/kwh in RavCharge.)

Remember that the range projected by RavCharge is a function of the miles/kwh value you select, while the Entune range (Guess-o-Meter) is a function of things we don't know. It's really pointless to compare them. If, and only if, you find your RavCharge range to be consistently optimistic compared to your actual range, then I would suggest lowering the normal charge capacity setting.

My testing indicates that for most users the default of 35kwh will provide the best results for both range and time-to-charge projections. You should adjust your projected range for a given drive by varying the miles/kwh slider, not the normal charge capacity setting.

 

[waidy]

Hi Hi, is there a possibility to pull the ROC (rate of charge) to RavCharge while charging? For example, my car is being charged in a public garage, it is not easy (other than ChargePoint) to find what the EVSE's fed voltage and amperage is ( I can guess but why guess if the information is there). The slide bar is good but it is not as good as getting real data. Mucho thanks.

 

[fooljoe]

Hi Hi, is there a possibility to pull the ROC (rate of charge) to RavCharge while charging? For example, my car is being charged in a public garage, it is not easy (other than ChargePoint) to find what the EVSE's fed voltage and amperage is ( I can guess but why guess if the information is there). The slide bar is good but it is not as good as getting real data. Mucho thanks.

Yeah, I've thought about doing this. There's no ROC value provided by Entune (or the car), but we can estimate the rate based on how your SOC changes over time while charging. Of course you couldn't get an instant display of this information, as RavCharge would have to do two status updates some time apart during charging, and the longer that time is the more accurate the info will be.

So there'd probably have to be some button you push when charging to start the periodic sampling process, then you'd have to come back ~10 minutes later to see what rate you're getting. I'll see what I can do.

In the meantime if you take note of what your SOC% is in RavCharge before you start charging (and note when you start charging), then do an "Update now" sometime after charging, you can fairly easily estimate the charging rate yourself, as such:

(SOC_after-SOC_before)/(time_after-time_before)*normal_charge_capacity

Make sure the SOCs are decimals (i.e. .55 for 55%) and the elapsed time is in hours if you want your answer to be in kw. Note that this will be the rate into the pack - if you want to estimate the power at the wall divide by charging efficiency. I've found 0.8 works reasonably well for that.

 

[waidy]

Yeah, I've thought about doing this. There's no ROC value provided by Entune (or the car), but we can estimate the rate based on how your SOC changes over time while charging. Of course you couldn't get an instant display of this information, as RavCharge would have to do two status updates some time apart during charging, and the longer that time is the more accurate the info will be.

So there'd probably have to be some button you push when charging to start the periodic sampling process, then you'd have to come back ~10 minutes later to see what rate you're getting. I'll see what I can do.

In the meantime if you take note of what your SOC% is in RavCharge before you start charging (and note when you start charging), then do an "Update now" sometime after charging, you can fairly easily estimate the charging rate yourself, as such:

(SOC_after-SOC_before)/(time_after-time_before)*normal_charge_capacity

Make sure the SOCs are decimals (i.e. .55 for 55%) and the elapsed time is in hours if you want your answer to be in kw. Note that this will be the rate into the pack - if you want to estimate the power at the wall divide by charging efficiency. I've found 0.8 works reasonably well for that.

That's great!! You are ahead of me. I honestly seldom use public charging, and if I use it, it's opportunity charging where I don't really need the juice. Today I have the need to use public charging because I purposely didn't charge it at home last night. That's a bummer that enTune does not provide the ROC information. Some EVSEs like ChargePoint has the capability to do load shedding. I.E. when more than $N EVs plugged into the infrastructure, each EVSE would balance its load so that the total kW is equal or less than $E. In another word, the ROC is changing over time pending on how many EVs are being fed.

 

[waidy]

I am used to reading SOC that is 100% base (that is, in this case, 41.7 kWh). For example, when my Rav completes its "normal" charge, I want to see it said 80%. I understand others want to see normal charge as 100%. Is there a way RavCharge would let me ask it to calculate it using 41.7 kWh? I looked in "Setting" but all it offers is for "normal charge capacity".

To give an example, if I go on vacation I want to charge it to 50%. So this 50% represent 50% of 41.7kWh and I want my RavCharge tells me that. [While driving, I always multiple the number of bar by 5 and hardly look at the GOM number]

 

[fooljoe]

I am used to reading SOC that is 100% base (that is, in this case, 41.7 kWh). For example, when my Rav completes its "normal" charge, I want to see it said 80%. I understand others want to see normal charge as 100%. Is there a way RavCharge would let me ask it to calculate it using 41.7 kWh? I looked in "Setting" but all it offers is for "normal charge capacity".

To give an example, if I go on vacation I want to charge it to 50%. So this 50% represent 50% of 41.7kWh and I want my RavCharge tells me that. [While driving, I always multiple the number of bar by 5 and hardly look at the GOM number]

I doubt if many others want to see 100% be a full normal charge, but that's just the way Toyota chose to set up the car's instrumentation and interface with Entune, so it made sense to do the same in RavCharge. But sure, I suppose making this change is possible at least as a purely cosmetic tweak (i.e. it won't change any other calculations/functionality.) I'll look into adding a setting option to display SOC that way.

Realize your SOC would never go above 84% (if 41.8kwh is your 100% base then that's what a normal charge represents), even if you do an extended charge, so you'll lose a little granularity (instead of 101 possible values you'd have 85 possible values - I think it would be misleading to add a significant digit.) Also if you read through a bunch of posts a few pages back you'll see that there's much speculation about what the "real" cell-level SOC is, and it's pretty clear that 41.8kwh doesn't really equal 100% either. So if you want to store your cells at the real 50% level you're going have to make some assumptions/calculations of your own one way or another.

In the meantime, if you want a more absolute measure of charge you can always look at the 'approximate charge' value instead of SOC%. If you want to be at 50% of 41.8kwh then you should just get approximate charge to 20-21kwh (59-60% of a normal charge.) If you believe a full normal charge is actually 80% of the cell-level SOC then that means you should instead target 21-22kwh, or 62-63% of a normal charge (50/80 = 62.5%).

 

[yblaser]

fooljoe, I think I followed you home for about 15 miles this evening unless there is someone else with a RAVCharge.com sticker on their rear window . I appreciate your efficient driving style