Range anxiety???

[Dsinned]

It seems to me, that there are certainly other forms of "range anxiety" far more serious. For instance, piloting an aircraft, would probably be at the top of the list.

Range anxiety in a purely BEV like the RAV4 EV, a car that can go over 100 miles on a standard charge (or at least 20% further if extended) is not so much of a worry. Just like an pilot, you just have to make sure of your "preflight" preparations before every trip, know your route distance in advance, and always remember to bring your OEM charger in case of some unanticipated route change that takes you miles "out of the way". You also have to "know" your instrumentation's accuracy, and always err on the side of overly conservative.

Again, driving a RAV4 EV is a lot like being an private plane pilot. There really are a lot of similarities, as far as range anxiety. Except when range is overestimated in an aircraft, it matters not which kind, that can have terrible consequences for all aboard. The worst that can happen in a RAV4 EV is for driver and passengers being held up somewhere for several hours while recharging at 115 volts. But, if you ever run out of "energy" in a plane, you're probably about to DIE!

 

[HD172]

I agree with preplanning. I don't fully trust the fuel gauges in my airplane and I don't fully trust the GOM in the Rav4. I know how much they hold in energy and I know how much energy I use. I err on the side of safety and I haven't run out of gas or electricity yet.

 

[Joyride]

Practicing to learn your own capabilities and those of your vehicle are also key. I'm planning a "practice" run from my home in Costa Mesa to Santa Barbara later this month to get a better feel for how well both my car and myself do with longer range drives. The trip is about 132 miles according to Google Maps, and I could probably do that on a standard charge. However, I am planning to do an extended charge, at least for the trip there to make sure everything goes well.

This is also a low risk test because there are a TON of charging stations along the way. Still, I'm looking forward to learning more about my car and myself along the way. This, to me, is the first step in looking for and planning longer range adventures beyond the comfort of a simple day trip.

-Chris

 

[SeattleRav4]

Maybe you guys can help me out. I am trying to buy a RAV4 EV in CA. It would be fun to drive it back but given the lack of a fast charge capability it does not look practical. If I drove I-5 and charged at each station, how long would a charge take?

thanks

 

[TonyWilliams]

A FULL charge on a Tesla EVSE (you would need a very hard to find adapter, although some now have J1772) or from a NEMA 14-50 plug at an RV park (which will call it "50 amp" service) will provide 50kW in 5 hours if you have a 40 amp EVSE. That will provide the 41.8kWh usable power that the battery holds.

The Rav4 will travel 140 miles at 65mph (3.4miles/kWh) on level roads with no cabin or battery heating and take two and one half hours (140 / 60mph average speed = 2.5 hours).

The 40 amp max charge rate will provide 28 miles per hour of charging at 65mph driving speed (5 hours * 28 miles per hour of charging will provide, once again, 140 miles of range).

So, on our perfect flat, dry highway world at 70F or higher ambient, you will drive 2.5 hours and cover 140 miles, then charge 5 hours at the perfectly placed 40 amp charger. Every 7.5 hours, you can cover 140 miles in absolutely perfectly ideal conditions. But, the real world isn't so kind!

In 21.5 hours, your range is 420 miles at 65mph, so lets just say about 400 miles per day MAX. It's about 800 miles from San Fran or Sacramento to Seattle, therefore 2 perfect days (which really means four real world days !!!)

 

[SeattleRav4]

Ouch
First thanks for the well calculated reply. That is much better detail but about what I was guessing.

Pretty much says it will have to be shipped.

 

[TonyWilliams]

Ouch
First thanks for the well calculated reply. That is much better detail but about what I was guessing.

Pretty much says it will have to be shipped.

You could probably find somebody to drive it (maybe a family member or friend with an adventure streak) while touring the west coast.

There are TONS of good shippers. Ask the dealer you are using to arrange it. There are several high volume LEAF dealers that ship all over; call them (Fontana Nissan and Mossy Nissan Kearney Mesa).

The Toyota dealer in Carson has lots of Rav4s in stock, and a great sales lady who specializes in these and the Prius. I'm confident she can hook you up.

Dianne Whitmore
Carson Toyota (near LA)

 

[SparkyAZ]

Does anybody have any data on the mileage / temperature derating curves for the rav4EV? I'm curious because my daily commute is 60 miles (up to 80 miles if I do other errands) round trip. I can't guarantee being able to charge at work (not yet although I'm working on this). It can get up to 115F here on a regular basis during summer months.

I'd like to find out if Toyota uses active (liquid) cooling on their battery (I would suspect they do). I would also be interested to see mileage derating factors for running accessories such as headlights, A/C, and heater. I very rarely use the heater in my ICE car but use the A/C all the time during summer months due to my locale. My worst case scenario is running A/C and headlights at freeway speeds in high temps.

Also, has anybody seen or heard what anticipated capacity loss over time is expected with the Rav4EV pack? The initial range estimates seem doable, but if there is say a 20% capacity loss over 5 years it will get to the point of being on a thin margin of meeting my daily commute requirements without recharging at work.

 

[TonyWilliams]

Did you see the Range Chart thread?

The Tesla battery does use a thermal management system (TMS), with a dedicated heater located behind the underhood assembly, on the passenger side. The 6kW cabin heater is located on top of the 10kW liquid cooled Tesla charger

It uses the same air conditioner pump for both cabin and battery cooling.

20% battery capacity loss is likely in 5-10 years, depending largely on how well the pack was treated. High levels of charge over time and heat are the two killers of lithium chemistry cells.

The Nissan LEAF has no TMS, and its range of degradation is largely dependent on how hot the environment is. Phoenix LEAFs are wilting in the heat. Tesla Roadster, not so much.

But, if I parked ANY TMS equipped car unplugged in the heat, at some point of SOC%, the TMS quits and the battery is exposed to the elements, just like the LEAF.

 

[Dsinned]

Tony, what's worse for Li-ion batteries, high heat or extreme cold? Both are equally bad for most batteries, but which is worse for Li-ion? In the old days of Pb acid car batteries, extreme cold would kill their ability to hold a charge. I suppose electrolytes in those type of batteries can actually freeze in extreme cold temperatures. During the hottest days of Summer with no way to charge, we can help to mitigate battery heat by parking in the shade or in a garage. But in the extreme WInter cold, I guess our only recourse is to stay plugged in as much as possible, especially overnight.

 

[TonyWilliams]

You would have to qualify extreme cold, but generally, the colder the better.

Li batteries freeze at about -30C, so I don't recommend that cold. You don't need to leave it plugged in for short jaunts (daytime in blazing hot Phoenix parking lot) if the car is sufficiently charged to operate the TMS (I don't know the threshold SOC yet).

 

[SparkyAZ]

Did you see the Range Chart thread?

I did, thank you for posting that. The chart assumed ideal conditions with no capacity degradation. I would like to see the range derating curves vs temperature, if such data exists. I'm sure Toyota knows it, but may not be willing to publish it.

The Tesla battery does use a thermal management system (TMS), with a dedicated heater located behind the underhood assembly, on the passenger side. The 6kW cabin heater is located on top of the 10kW liquid cooled Tesla charger

It uses the same air conditioner pump for both cabin and battery cooling.

Thank you for clarifying, Tony. I did not see this in the range thread or anywhere else (maybe I just overlooked it). I would really like to get my hands on a service manual for this vehicle to learn more about the "innards". Maybe will have to do a short subscription to The Toyota tech site to download.

20% battery capacity loss is likely in 5-10 years, depending largely on how well the pack was treated. High levels of charge over time and heat are the two killers of lithium chemistry cells.

The Nissan LEAF has no TMS, and its range of degradation is largely dependent on how hot the environment is. Phoenix LEAFs are wilting in the heat. Tesla Roadster, not so much.

But, if I parked ANY TMS equipped car unplugged in the heat, at some point of SOC%, the TMS quits and the battery is exposed to the elements, just like the LEAF.

Agreed. LiIon batteries like to be stored at 50% SOC and at cool temps. Even though I am fortunate to have covered parking at work, the air and ground temps get pretty toasty during the summer and active cooling would be a must for driving in this climate.

 

[TonyWilliams]

Did you see the Range Chart thread?

I did, thank you for posting that. The chart assumed ideal conditions with no capacity degradation. I would like to see the range derating curves vs temperature, if such data exists. I'm sure Toyota knows it, but may not be willing to publish it.

Yes, it is set up for a "standard", just like performance charts are in aircraft. Then, we adjust from the standard.

The LEAF Range Chart does have several pages of charts with various capacities to calculate for degradation and impact of ambient temperature. We use a simple temperature rule of thumb on the LEAF:

1% loss of battery capacity for each 4F degree temperature below 70F.

Naturally, this won't directly apply to a TMS equipped battery.

Determining degradation can only be done with a test so far. I presume there will be a signal found in the EV-CAN bus that will give us capapcity, but we have not found that yet.


http://www.mynissanleaf.com/viewtopic.php?p=101293#p101293

 

[Damchi]

Thank you for clarifying, Tony. I did not see this in the range thread or anywhere else (maybe I just overlooked it). I would really like to get my hands on a service manual for this vehicle to learn more about the "innards". Maybe will have to do a short subscription to The Toyota tech site to download.



I posted a link to some PDFs from Toyota on a thread called "some PDFs I found"

http://www.myrav4ev.com/forum/viewtopic.php?f=2&t=70