50 kW RAV4 EV battery maximum charger input power?

[swogee]

What is the absolute maximum power the RAV4 EV battery can accept while charging? I know the JDEMO that is installed allows the use of 50 kW chargers but there are larger chargers on the horizon. I have been researching future charging stations and Chargepoint just announced a unit that will supply a maximum of 400 kW. I believe the specs mentioned it was 1000 V at 400 A max.

I know the RAV4 EV has a 386 volt battery. I read in a post the JDEMO charge current is 120 A, so obviously it would not able to accept anything close to 400 kW. Is 50 kW the most power the battery can acccept? Can the battery be charged at higher currents if available? For example if a 62.5 kW or 125 kW charger was used vs a 50 kW unit? What modifications would be required to the JDEMO? Finally how does Tesla handle their battery charging setup with 120 kW max power?

 

[TonyWilliams]

Signet, ABB, and Efacec all offer 125 amp DC chargers. That is "62.5kW" ... 500 volt * 125 amps. Yes, they are commonly referred to as "50kW".

Don't let the kilowatt number mislead you, because it is entirely dependent on what the battery voltage is for any given car. The output DC amps is important.

The current 125 amp Tritium Veefil sold by ChargePoint is great (there's two in Buellton). Almost universally they all require 480 VAC, 80 amp per phase. BTC produces a unit they can operate off of 208 volt 3 phase, not sure but probably 180-200 amps per phase? The output is 100 A DC, so a little slower than all the others.

This new ChargePoint unit has a configuration with 156 amps DC output, so a bit of an oddball.

The next step up in chargers is 200 A DC. Signet is the only one that I'm currently aware of offering 200 amp chargers, and it may be hard to find in the US.

The next step up after that is 350 A DC, which will likely be the new standard going forward.

Any of the units can be limited to power through software, so that 350 amp charger could easily be reduced to a 200 amp charger, or 125. The new ChargePoint unit is capable of 400 amp DC for a limited charge time with a liquid cooled plug. Don't worry... few cars could take 400a. Tesla is at 365a max now.

The RAV4 EV can probably take somewhere between 125 and 200 A DC. The current max is 125.

The current 45 kW max rate is approximately 1C. At 200 A DC / 65-70kW max, we would be somewhat below 2C.

The limitation won't be the cells as much it will be the waste heat rejection capability of the RAV4 while charging.

The simple answer as to modifications to JdeMO are that a simple software update would be required. But, beyond that, we don't know what limitations there may be in terms of the battery, the Toyota / Tesla software, the cooling capabilities, etc.

 

[miimura]

Tony,

Do you plan to find the heat rejection limit and just set the max current there, or could you have the system charge faster to start and just reduce the current to stay under some temperature limit? In cold weather, like driving to Tahoe, it would be nice to be able to charge faster when the cooling system is more efficient.

Also, what is the rating on the Yazaki inlets that were installed? Are they rated for 200 amps? What about the HV cables between the inlet and the battery pack?

 

[TonyWilliams]

Tony,

Do you plan to find the heat rejection limit and just set the max current there, or could you have the system charge faster to start and just reduce the current to stay under some temperature limit? In cold weather, like driving to Tahoe, it would be nice to be able to charge faster when the cooling system is more efficient.

Also, what is the rating on the Yazaki inlets that were installed? Are they rated for 200 amps? What about the HV cables between the inlet and the battery pack?

The relays are 800a rated, about 200a continuous.

Cables to the battery are 2 gauge, which likely can handle short term 200a (I honestly don't know right now). These can somewhat easily be made larger.

Inlet cables to the relays are the metric equivalent of 2 gauge. These cannot be made larger, therefore the single weakest link with the JdeMO hardware is this link.

After extensive testing, we will set the maximum amps at whatever is logical for the weakest link.

The battery temperature part is somewhat easy. If it gets warm, we reduce power. Nothing will change, except the maximum amps, plus we will add either one or two lines to the temp table:

10C to 45C cell temperature = 125a max
15C to 44C cell temperature = 150a max
17C to 43C cell temperature = 200a max

In addition, we will likely explore ways to manually run the cooling pump and air conditioning compressor at 38C.

 

[swogee]

Tony,

Thanks for all of the additional info on the JDEMO and the max charging power limitations on the RAV4 EV. I know that higher powered DC fast chargers aren't available yet, but they are going to be in the next few years.

It's too bad that we can't get access to the design specs of the RAV4 EV's battery cooling system to determine how much heat it can reject. I suppose it's not surprising given all of the liability concerns these days.

It's also nice to know that there still may be a bit more power that JDEMO can utilize when it does become available. Finally, if by some slim chance the battery pack is upgraded to use newer higher capacity 18650 cells the JDEMO may be able to accommodate the additional power required to charge it.

 

[n3ckf]

a very few times i've been charging my car with JDEMO and it was 95F (there's one location i charge that gets that hot regularly in the summer), i leave the A/C on in the car. (set to "normal"). That was on a 115Amp charger.

How much does running the A/C in the vehicle protect the battery when using JDEMO? (and its hot out). Should i do this at even lower temperatures? (I've been informally doing it whenever ambient is > 90F)

 

[TonyWilliams]

a very few times i've been charging my car with JDEMO and it was 95F (there's one location i charge that gets that hot regularly in the summer), i leave the A/C on in the car. (set to "normal"). That was on a 115Amp charger.

How much does running the A/C in the vehicle protect the battery when using JDEMO? (and its hot out). Should i do this at even lower temperatures? (I've been informally doing it whenever ambient is > 90F)

If the green button isn't quickly flashing when you're charging, the battery didn't get too hot and was charging at full speed.

Yes, if hot out, set A/C to "AUTO", which will keep the cells the coolest. The ECO modes typically allow the cells to get warmer to save power.

 

[ferenc]

Hmm, I was told that my home charger is not compatible with my EV.
This puzzled me, as I assumed that the level2 charger is controlled by the RAV4 - including start/stop and rate of charge.

Is that not the case?

Googling returned this link: http://www.plugincars.com/report-toyota-rav4-ev-not-compatible-some-level-2-charging-stations-125166.html

Ferenc

 

[TonyWilliams]

Hmm, I was told that my home charger is not compatible with my EV.
This puzzled me, as I assumed that the level2 charger is controlled by the RAV4 - including start/stop and rate of charge.

Is that not the case?

Googling returned this link: http://www.plugincars.com/report-toyota-rav4-ev-not-compatible-some-level-2-charging-stations-125166.html

Ferenc

Why don't you tell us what charge station you have. EDIT - is this what you have? "ClipperCreek HCS-60"? That will work perfectly.

If you're worried about having one ordained by Toyota, here is the list:

Toyota is notifying dealers of the situation and has listed these chargers that as fully compatible with the RAV4 EV:

Leviton (exclusive EVSE supplier for the RAV4 EV) offers fully approved 16 amp, 30 amp and 40 amp charging stations.
Aerovironment: Level 2 EVSE-RS
Blink/Ecotality: Level 2 Charge Station (subsequently taken off the list in July 2013)
ChargePoint/Coulomb Technologies: CT2000 Series
Clipper Creek: CS Series
Eaton: EV Charging Station (residential)
Eaton: Pow-R-Station (commercial)
Schneider Electric: EVLink Indoor Charging Station (EV2430WS)

***************

If you want one that works, don't buy or use:

1) 2011-2012 Nissan LEAF / Panasonic EVSE
2) GM Voltec EVSE

 

[ferenc]

When I complained that the car was not sticking to the programmed charging schedule (by departure) on a consistent basis, they said it was because my home charger was not compatible/approved.

As I'm on the PG&E EV rate plan, I set things up to be ready by a 6:30AM departure - which, if fully empty, should start charging the batteries around 2AM. I'd heard it start as early as 10PM. Are they saying the factory approved charger requires 2x as long to fully charge the battery pack? I recall reading somewhere that there were some s/w issues with the 'charge by departure' setting - my local dealers tend to ignore/deflect pesky problems ...

Thanks for listing the factory appporved chargers from the web page I supplied in m previous post - was it more 'current?' No pun intended,
Ferenc

 

[TonyWilliams]

When I complained that the car was not sticking to the programmed charging schedule (by departure) on a consistent basis, they said it was because my home charger was not compatible/approved.

As I'm on the PG&E EV rate plan, I set things up to be ready by a 6:30AM departure - which, if fully empty, should start charging the batteries around 2AM. I'd heard it start as early as 10PM. Are they saying the factory approved charger requires 2x as long to fully charge the battery pack? I recall reading somewhere that there were some s/w issues with the 'charge by departure' setting - my local dealers tend to ignore/deflect pesky problems ...

Thanks for listing the factory appporved chargers from the web page I supplied in m previous post - was it more 'current?' No pun intended,
Ferenc

There is a very well worn path (and an associated thread) for every circumstance that you're likely to encounter.

Toyota is never going to update the approved charge station list. Many of the people at the dealership are poorly trained monkeys who just plod along the best they can with this car (they may be great with a Camry or Tundra). The Rav4 EV is an albatross for Toyota.

The charge station did NOT cause a problem with timer. The selection on the screen is not a "start" timer... it's a poorly done end timer. With practice, you'll be able to set that to within an "hour or two" of when you really wanted the charge to end. I set mine for 7am, and it normally finishes at 3am to 5am. The start time is wholly dependent on how much power is available to charge. Please reference the thread about charge timers:

http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=172

 

[smkettner]

Toyota is notifying dealers of the situation and has listed these chargers that as fully compatible with the RAV4 EV:

Leviton (exclusive EVSE supplier for the RAV4 EV) offers fully approved 16 amp, 30 amp and 40 amp charging stations.
Clipper Creek: CS Series
Schneider Electric: EVLink Indoor Charging Station (EV2430WS)

Well it is about time!

I use Leviton 16, LCS20, and the Schneider on a regular basis.
When I had charging problems due to the gateway computer malfunction all three dealers said all three of these EVSEs should be avoided.
Only the 40 amp Leviton was approved :roll:

I guess it is similar to dealers that claim bad gas when they cannot fix a regular car. So typical to blame the customer with FUD.
Did I ever mention how I hate dealers? Good on Tesla to be rid of them.

 

[fromport]

Did I ever mention how I hate dealers? Good on Tesla to be rid of them.

I basically agree.
On the other hand, it would make sense if _we_ could go to a tesla dealer to have the tesla parts in the rav4ev serviced once we are out of warranty.