Hypermile tips - disappointing range?

kiwiguy said:

Tony - can you tell us more about this Tesla Roadster adaptor you speak of?
I assume it allows you to charge a J1772 EV from a Roadster charger?
I haven't seen such a thing before. Only the other way around.

Thanks!

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Yes, i can do all that. You probably never heard of it because i have the only one.

Basically you just take the Roadster to Model S adapter, hack off the Model S plug and replace it with a J1772 plug, just like you do for the Jesla, right? It ain't cheap, but it'll do the job.

If you could somehow find an inlet from a junked Roadster or otherwise, or perhaps even 3d print one, you could build your own adapter for much less I imagine.

fooljoe said:

Basically you just take the Roadster to Model S adapter, hack off the Model S plug and replace it with a J1772 plug, just like you do for the Jesla, right? It ain't cheap, but it'll do the job.

If you could somehow find an inlet from a junked Roadster or otherwise, or perhaps even 3d print one, you could build your own adapter for much less I imagine.

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Yep, thats what I did.

Those Roadster inlets are made by Amphenol, but trying to get one ain't easy.

TonyWilliams said:

First question, do you have a JESLA or other method to get 40 amps from a NEMA 14-50?

Second, SLOW DOWN !!! Find a truck and match his speed... 55-58mph is typical. Do NOT draft too closely and compromise safety.

Third, run the air conditioner. It is VERY efficient and it is running anyway to cool your battery. The very few miles you'll lose from cooling the cabin will mostly be offset by having the windows up.

Fourth, I think you are using GOM values for your trip, and that is never going to work well.

NOTE: I have a Tesla Roadster adaptor

135 miles - Rabobank Salinas CC - 70a/240v - free

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Yes I do have a JESLA actually and that is why I was hoping to find a NEMA 14-50 outlet to charge from. Unfortunately, neither of the RV sites in Monterey are open to the public right now. (The NAVY RV campground and the Monterey County Fairground RV campground.) I was trying to think of a friend that might have a NEMA 14-50 outlet available, but I think they were typically installed in newer homes (beginning in the 1990's) for the range.

I figured keeping the speed down to 55 would extend the range, but is drafting an absolute requirement as well? How many car lengths back does a person need to be to still take advantage of drafting? There is an element of risk as mentioned.

I don't put the windows down at freeway speeds as it creates additional drag, however if the temperature is cool enough outside (like at night) I do shut off the HVAC system and just let the air flow through the vents on its own.

On the initial trip that failed up to Monterey I used the GOM, but after additional driving time with RAV4 and more research including the range chart that I figured each bar segment is good for about 6 miles at 65 mph. I'm assuming it would be up to 8 miles at lower speeds such as 55 mph.

I did in fact charge at the Rabobank in Salinas after being towed there. It took 6.5 hours to fully charge. Salinas is not my destination though and choices are limited in Monterey. There is a CHADEMO in Monterey, but it's not much use to me at this point.

Thanks for all the tips. It looks like I have decide if 14 hours will work for this trip.

Why not just make it into an overnight trip? Find a hotel that either has a charging station or is relatively near one, then those ~8 hours of charging in Monterey can happen while you sleep.

For the 150 miles to get there, you could possibly hypermile to get there on one charge, but that'd be pretty tough. With a fully-loaded car and a bit of hill climbing, you'd probably have to go <50 mph to achieve the needed 3.6 miles/kwh to make it there, so I'd plan a charging stop. But stopping merely 19 miles from your house won't help much, since charging slows down a lot ("the taper") as you near 100%. Plus the most you could replenish is 19 miles.

Try to find somewhere you can stop that's further along the route and also has somewhere to grab breakfast or lunch. Even if it's a 30a instead of 40a EVSE, you'll be charging faster because your car won't be in the taper zone. If you can find a 240v EVSE, that's even better.

How about one of the stops in King City? You've got a 30a ChargePoint at Hartnell college that apparently has a Mexican joint nearby, or the Ciudad del Rey Motel & Trailer park that has a 14-50 and also has a restaurant.

And you'd still be well-served to take it as slow as you can getting there, as your overall trip is always faster by driving slower. Realize also that you don't need to top it off all the way to make it to your destination. With only ~70 miles left to go, you'll probably be safe getting it up to about 75% (of normal), depending upon how efficiently you're driving.

What is this "taper zone" mentioned in the previous post? I have closely observed charging my RAV4 from a 32A L2 EVSE and do not see any such thing; at least not more than a few minutes near the expected end a normal charging event. The EVSE is supplying AC power at a constant rate to the car via the J1772 charge port connector. Conversely, what I have observed during an overnight charge (start at midnight, end by 9am) is a "reactivation" of charging, after a long delay of usually several hours, but at a much lower rate (~1/10 of normal) for about 20 minutes past the scheduled departure time. I don't believe this forced cooling (or heating) initiated by the BMS either. I have observed this unexplained and unexpected relatively short reactivated charging event many, many times and am assuming all RAV4 EVs do the same thing. I "think" this is some sort of cell balancing and/or topping off charge, that never varies in duration or from a very low level charging rate (~700kW), which implies it is something Tesla must have pre-programmed into the BMS for some reason.

fooljoe said:

... your overall trip is always faster by driving slower.

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...with existing charging speeds on the Rav4 EV.

With JdeMO and properly spaced CHAdeMO chargers, I hope that's no longer the case.

Dsinned said:

What is this "taper zone" mentioned in the previous post? I have closely observed charging my RAV4 from a 32A L2 EVSE and do not see any such thing; at least not more than a few minutes near the expected end a normal charging event.

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Obviously, the taper start earlier at a 40 amp rate than at a lower rate.

I have witnessed the 40 amp pilot signal reduced to 20 amps, and you're right, it's near the end. Maybe we should plot out exactly when the taper starts relative to SOC% ?

Seems like we travel the same routes. As far ad 154 vs 101, it takes less power to go over 154, I drive 154 every day. I go from Solvang to Atascadero often, I do a standard charge, st for coffee in SLO at target for about 15-20 min and arrive in atas with two bars left, I drive 65-70. If your headed south and want a free charge, there are 2 chargers at El Rancho in Santa Ynez, they are in the back and a little hidden, but free, (208 30a). Also there is a place to sot and eat in the shade, the owner loves evs and is allways happy yo see people using his charger. In SB there are many chargers in the public lots, and I have never not been able to charge there. Also if you want free there is a charge point free charger at the BMW dealer in SB, again it's hidden and they don't let people use it during business hours. Any other questions about the SB SYV area let me know.

swogee said:

TonyWilliams said:

Second, SLOW DOWN !!! Find a truck and match his speed... 55-58mph is typical. Do NOT draft too closely and compromise safety.

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I figured keeping the speed down to 55 would extend the range, but is drafting an absolute requirement as well? How many car lengths back does a person need to be to still take advantage of drafting? There is an element of risk as mentioned.

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The best speed is close to 20mph, so anything over that is "waste". Of course, we have to flow with normal traffic, so 20mph isn't practical or safe.

DONT GET TOO CLOSE TO A TRUCK !!!

My brother completed his final JESLA charge at Maryhill State Park (NEMA 14-50 equipped) in Washington state to complete his 4 day trip from San Diego to his house. I think he used RV parks exclusively through Oregon and Washington.

TonyWilliams said:

Dsinned said:

What is this "taper zone" mentioned in the previous post? I have closely observed charging my RAV4 from a 32A L2 EVSE and do not see any such thing; at least not more than a few minutes near the expected end a normal charging event.

Click to expand...

Obviously, the taper start earlier at a 40 amp rate than at a lower rate.

I have witnessed the 40 amp pilot signal reduced to 20 amps, and you're right, it's near the end. Maybe we should plot out exactly when the taper starts relative to SOC% ?

Click to expand...

Dsinned, I'm talking about how charging slows near the end of an extended charge. Refer to this post where you showed a plot of your power consumption during an extended charge. It's not a long period, about 20-25 minutes in your case with a 32A EVSE, so probably ~30 minutes with a 40A EVSE, but I bring this up in the context of swogee's post about driving only 19 miles before topping off (an extended charge) from a 40A public EVSE for his 150 mile drive. In that case the slowing from the taper would be pretty significant.

Thanks for all of the replies.

It is interesting that the last time I tried to make this trip we stopped in Atascadero to charge at the Rabobank with the CC/Tesla EVSE and it took about an hour and half to fully charge. I was a little surprised as we had only gone 19 miles but I attributed the the slow charge time to in the heat (it was 102 that day) and the additional energy used to climb Cuesta Grade with a 1500 ft elevation.

I would stay in Monterey if I had time, but I will be back up there again on Tuesday for business. The trip I was considering to Monterey this Sunday was only supposed to be for a 4 hour event.

sbportech, thanks for the info on the SB charging locations and the Santa Ynez El Rancho Mkt charging locations. It sounds like the CC EVSE units near the El Rancho Mkt/California Fresh in Pismo Beach. I was curious about the BMW dealer EVSE usage since on plugshare it specifically mentioned that the dealership was hostile to all non-BMW vehicles using the charger station. Is the station actually accessible during non-business hours or do they block it off?

I guess I have to decide if the 14 hour trip is worth the money savings.

Thanks again for all of the thoughts and ideas.

TonyWilliams said:

Dsinned said:

What is this "taper zone" mentioned in the previous post? I have closely observed charging my RAV4 from a 32A L2 EVSE and do not see any such thing; at least not more than a few minutes near the expected end a normal charging event.

Click to expand...

Obviously, the taper start earlier at a 40 amp rate than at a lower rate.

I have witnessed the 40 amp pilot signal reduced to 20 amps, and you're right, it's near the end. Maybe we should plot out exactly when the taper starts relative to SOC% ?

Click to expand...

By using two different, independent means for measuring EVSE charging rates, each with data point sampling of once per minute, I clearly see a "taper" during the last several minutes on my Chevy Volt, while charging at 3.3kW, but not nearly as pronounced on my RAV4 EV at 7.7kW. The charging rate drops from 7.7kW to zero in a matter of only a couple minutes which is hard to characterize when the sample rate is at one minute intervals plus there is some additional latency in the feedback loop using a WiFI Internet network to capture the data. If the BMS in the RAV4 ramps down at a slower rate when the maximum charging rate is near 10kW (40A), but ramps down much faster at a charging rate of 7.7kW (32A) or lower, I guess that explains the difference in taper rates.

fooljoe said:

TonyWilliams said:

Dsinned said:

What is this "taper zone" mentioned in the previous post? I have closely observed charging my RAV4 from a 32A L2 EVSE and do not see any such thing; at least not more than a few minutes near the expected end a normal charging event.

Click to expand...

Obviously, the taper start earlier at a 40 amp rate than at a lower rate.

I have witnessed the 40 amp pilot signal reduced to 20 amps, and you're right, it's near the end. Maybe we should plot out exactly when the taper starts relative to SOC% ?

Click to expand...

Dsinned, I'm talking about how charging slows near the end of an extended charge. Refer to this post where you showed a plot of your power consumption during an extended charge. It's not a long period, about 20-25 minutes in your case with a 32A EVSE, so probably ~30 minutes with a 40A EVSE, but I bring this up in the context of swogee's post about driving only 19 miles before topping off (an extended charge) from a 40A public EVSE for his 150 mile drive. In that case the slowing from the taper would be pretty significant.

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Oh, okay, my bad. I forgot about what happens during an "extended" charge. My own data gathered from last year demonstrates that there IS a taper of some significance by the end of an "EXTENDED" charge! This makes sense too, because an extended charge takes the battery much closer to a level of 100% SoC, so tapering off is more important to avoid a rapid heat build up that could potentially harm the cells. The taper is probably even more evident when charging at 10kW (40A) and as Tony said, will start even sooner.

The BMW charger is not blocked off but it can be trickey to get to. The issue they have is lack of parking during service hours. The el Rancho is a CC 30 amp, I use it when I go to the market and it was handy when I coasted in on turtle coming home one night from SB. I wish everyone was SLO with chargers, I miss living there.

swogee said:

Thanks for all of the replies.

It is interesting that the last time I tried to make this trip we stopped in Atascadero to charge at the Rabobank with the CC/Tesla EVSE and it took about an hour and half to fully charge. I was a little surprised as we had only gone 19 miles but I attributed the the slow charge time to in the heat (it was 102 that day) and the additional energy used to climb Cuesta Grade with a 1500 ft elevation.

I would stay in Monterey if I had time, but I will be back up there again on Tuesday for business. The trip I was considering to Monterey this Sunday was only supposed to be for a 4 hour event.

sbportech, thanks for the info on the SB charging locations and the Santa Ynez El Rancho Mkt charging locations. It sounds like the CC EVSE units near the El Rancho Mkt/California Fresh in Pismo Beach. I was curious about the BMW dealer EVSE usage since on plugshare it specifically mentioned that the dealership was hostile to all non-BMW vehicles using the charger station. Is the station actually accessible during non-business hours or do they block it off?

I guess I have to decide if the 14 hour trip is worth the money savings.

Thanks again for all of the thoughts and ideas.

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UPDATE:

I decided to try to make another trip to Monterey in the RAV4 EV last Sunday as sort of a test to see how things would turn out. The wife and kids were in Sacramento and they were planning on meeting me later in Monterey as well. This time I left much earlier at 8AM as I figured the entire trip would take me at least 14 hours. I cruised at 55 mph the whole way which took some getting used to as everyone was passing me. I was planning on charging at Atascadero for an hour or so, but since that location was taken I continued up to King City. I charged for about 1.5 hours and then I continued up to Monterey. I decided not to go all the way into Monterey as the two charging stations downtown are usually occupied. I also decided not to drive out to Asilomar as that would have added 10 miles. I found a charging station just off Hwy 68 at the Monterey APCD that was open so I parked there and I let the RAV4 fully charge up. I had over 5 bars of charge left when I arrived at the APCD location. I probably could have easily made it into Monterey, but I figured I would just get a ride back to the RAV4, so to make the trip home shorter I just stopped at the APCD on Hwy 68. It took roughly 7 hours to fully charge the RAV4. I headed back home at roughly 9:15PM and got back to SLO at about 11:50PM. This time I managed to cover the 139 miles without stopping to charge. I had only two bars left when I arrived home. At the start of the trip home I was getting 8 miles per bar roughly, but it seems that later in the trip that dropped. I cruised at 55 mph the whole time again. I don't think I would have made it all the way into Monterey without stopping to charge as the climb up Cuesta Grade is steeper going north. Also if I had a fully loaded RAV4 with 5 people it would have used more energy. So it looks like going to North to Monterey will require a 2 hour and 45 minute driving time + at least a 1 hour charge. Returning home would likely require a charging stop as well, but a shorter one. If I could find a location to charge up faster it would have been nice as well, but those are few and far in between.

I forgot to mention the best AVG efficiency I was able to get on the trip was 3.7 miles/kWh, although it was usually closer to 3.6 miles/kWh. This was with my speed set at 55 mph on cruise control and no drafting behind trucks. I'm curious if this is typical for the RAV4 EV. I'm not sure how I could improve the efficiency beyond 3.5.

swogee said:

It took roughly 7 hours to fully charge the RAV4.

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There are few charging spots, but there are RV campgrounds with "50 amp" service.

With a JESLA and a NEMA 14-50 plug (included), you could have changed in less than 5 hours, plus had the versatility of many more places to charge.

JELSA will ship with a NEMA 14-50 and NEMA 5-15 plugs. Additionally, you may want to buy the correct plug for your dryer or for motel air conditioners:

....................................................VOLTS / AMPS.......kW
NEMA 5-15 .......Standard Outlet.. 120 V / 12 A...... 1.4 kW
NEMA 5-20 ...... Motel air conditioner 120/16A....... 1.9 kW
NEMA 10-30......Older Dryers...... 240 V / 24 A...... 5.8 kW
NEMA 14-30......Newer Dryers..... 240 V / 24 A...... 5.8 kW
NEMA 14-50......RV Parks ........... 240 V / 40 A...... 9.6 kW

Is there a list of RV parks that have 14-50 plugs available? I can make it down to the Santa Cruz area, but it'd be great to use the Jesla to charge up faster than the stations I've tried in the downtown.

Tadol said:

Is there a list of RV parks that have 14-50 plugs available? I can make it down to the Santa Cruz area, but it'd be great to use the Jesla to charge up faster than the stations I've tried in the downtown.

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I've seen people mention AllStays (web, iPhone & Android) but I've never used it.

I searched for All Stays on my android and the app cost $9.99. I'm not opposed to buying it if it's really worth it. I rarely buy apps though.