Tony-Test: How to Calculate Rated Range/Battery Degradation

[TonyWilliams]

I actually know what the pack voltage is .. It's 386.4 volts - Per Toyota (check the dismantling guide)
I also know, per Toyota a fully charged pack will go 152 miles at 60 MPH, so that is 3.6-3.7 miles per KW which would equal about 42 KW

Well, let's get the terms right! 42kW is POWER, 42kWh is STORED ENERGY.

Yes, if you look at my range chart, you will see that 60mph with a new condition battery with zero degradation will indeed consume about 3.6/3.7 miles per kWh on a level hard surface road, with warm weather, no climate control, no headwinds, etc. It's all on the range chart.

So, it seems, contrary to your opening salvo, that you now agree with my chart!!!

One more point; if 41.8kWh is available, or usable, then the battery MUST be slightly larger to keep the battery from being completely discharged. Lithium batteries don't handle that well. More on that below.

Now according to your own numbers of 92 cells in series (92 x 4.2 volts), that number matches ....386.4 volts
But the 48 in parallel, would equate the pack to to 48KW ( 2.6ah x 48 x 386.4) = 48.2KW

Well, again, 48kW is about 55-60 horsepower. But, since I think you mean 48kWh, then you're a bit too high. You can't base your stored energy calculation on the MAXIMUM voltage, since that voltage will drop all the way to 2.5 volts per cell during its discharge.

You also can't just calculate the average cell voltage range, for example ((4.2 volts * 2.5 volts) / 2) = 3.35 volts, since the stored energy is not linear to voltage.

So, the manufacture will generally publish a voltage to use for the calculation derived from testing. Try 3.65 volts per cell and see if you get something close to 45kWh for the RAV4 EV battery. When the battery is new and warm, it will provide 41.8kWh usable out of that 45kWh battery. The Tesla battery management system (BMS) will not allow the battery to be completely discharged.

Also to address the other post, yes I have connected to the car via techstream, and when I posted on this site that it showed 34.1 KW with regular charge which meant no degradation, it was you, yourself that dismissed it and said, it's not realistic.

You don't seem very open to coaching, so I won't go into the details of why that data doesn't help you determine degradation, but I have posted why on this site more than once. In detail.

You are also giving the BMS too much credit ... The capacity it calculates is based on how much it puts into the battery before it hits 4.2 volts ... I can send you many batteries that have a very high resistance, and will take more change than good 18650's with 2 AH capacity, yet not be able to provide more than .25 AH capacity.

I'm going to go with Tesla data over your very flawed understandings of our RAV4 EV.. Sorry.

You are also saying these are 2.6 AH Panasonic batteries, and they are charged to 4.2 volts, and if that is the case, then that means on the numbers that you provided, the pack is 48KW. and not 41.8, which means it's software limited ?,

No, they aren't "my numbers". I described above why your numbers are wrong.

and if so, then how can you truly measure degradation correctly ? Seems to me, you would not see any for 100K miles, unless you abused them to 5% SOC on every use.

Well, at least you're asking questions. That kind of information is all over the internet. If you want to believe that these cells don't degrade to 100,000 miles, I'll just suggest that you are quite the optimist. Realistically, these batteries will likely be around 20% degraded, plus or minus 5-10%.

Anyways, this has gone down enough rat roles .... For me it's a not a valid test of capacity, but for everyone that wants to do it, by ole means, it's definitely educational ...
I'll leave it be ...

Thanks ....

You popped on here, posted that everything was wrong, and that you had the "real" answers, and now you're done? You didn't really think I was going to let you slide, did you?

Good luck with your RAV4 EV.

 

[cooljw]

Tony,

Is it possible to only partially reset the GOM if you don't disconnect the battery for long enough?

I only had time to disconnect for 15 minutes, which resulted in 127 / 146 = 87% on mine which has 35k miles.

 

[TonyWilliams]

Tony,

Is it possible to only partially reset the GOM if you don't disconnect the battery for long enough?

I only had time to disconnect for 15 minutes, which resulted in 127 / 146 = 87% on mine which has 35k miles.

It's hard to say! That could be correct, and seems plausible, since that's about where I was at about 40,000 miles or so.

I'd try again after a full charge, then let the car sit for many hours (allowing cells to balance), then top off the car again.

Then, once topped off a second time, leave the 12 volt disconnected overnight.

 

[miimura]

I finally got around to doing the "Tony Test" GOM reset. I got 138 miles. I have had the car for 42 months and 37,000 miles. The car was manufactured in 11/2012 according to the information plate at the bottom right of the driver's door opening.

138/146=94.5%

 

[TonyWilliams]

I finally got around to doing the "Tony Test" GOM reset. I got 138 miles. I have had the car for 42 months and 37,000 miles. The car was manufactured in 11/2012 according to the information plate at the bottom right of the driver's door opening.

138/146=94.5%

I'm a little jealous, but I have more than double the miles.

 

[Airton]

At 100k miles I see 135 rated miles (92.4%) thanks Tony.

 

[Kohler Controller]

At 91k miles on my 2012, The Tony Test yielded 129/146 = 88%.

However, 125 miles was what was achievable when new, now I get around 95 miles and only when it is >80F. So that's more like 75% of original.

The only maintenance has been new tires, new 12V battery, new windshield due to rock (took months), replaced heater under warranty (took months), and air filters.

Motor whine has me approved (but still waiting after months) for a new drive train. Will get firmware upgrade (is the latest still 103?) and both recalls fixed (seat belt and wiper assembly) when it goes in the shop for the motor swap.

Still pretty impressive after 4 years.

 

[evbuddy]

36.5K miles, 2012 model @ 98%.

 

[locman]

2012 model, 89k miles, temp 50-60F overnight - 139/146 = 95%

I'm happy w this number, but i'm not sure i believe it
Meanwhile, with 80 miles commute each day with this car, it doesn't miss a beat. Awesome EV experience!

 

[co2112]

Finally did Tony test on replacement pack done at 71k miles. Have almost 9k miles since and am running at 141/146 or 3.5% degradation. Happy I didn't get a refurbished pack with more than 10% lost.

 

[SuedeGopher]

Adding a data point. 2014 w/22k miles and a 142/146

 

[miimura]

I finally got around to doing the "Tony Test" GOM reset. I got 138 miles. I have had the car for 42 months and 37,000 miles. The car was manufactured in 11/2012 according to the information plate at the bottom right of the driver's door opening.

138/146=94.5%

I just did an Extended charge about 7 hours after a Standard charge. It added 6 kWh in 47 minutes. That was more than I expected. Of course, that is energy from the wall, but it's still a lot of battery energy in the Extended portion.

I have nearly 45,000 miles on the car now.

 

[TonyWilliams]

That's a pretty solid battery.

 

[BrinkHouse]

Finally found the time to get this test done, did extended charge from 70% or so SOC to full on the 120v trickle charger, unplugged the battery for about an hour (all the time I had) and upon reconnecting saw 139mi on the GOM. 139/146 = just over 95%. Car has 34.5k miles on it and outside temp was approx. 75°.

Seems to fall in line with miimura's results above. One question, when I turned A/C to Eco Hi, the GOM dropped to 107. Is that just because we've reset the computer, or does the A/C really kill that much range?

 

[smkettner]

The deduction for the A/C is also reset. No, Eco-Hi should not actually take that much.
Deduction should adjust back to what it was before the test in a week or two.

I have stopped using eco A/C in the Summer as it has been said the standard mode provides better battery cooling.

 

[Christopher Castagne]

Finally did Tony test on replacement pack done at 71k miles. Have almost 9k miles since and am running at 141/146 or 3.5% degradation. Happy I didn't get a refurbished pack with more than 10% lost.

How did you get a replacement battery pack?

 

[co2112]

Finally did Tony test on replacement pack done at 71k miles. Have almost 9k miles since and am running at 141/146 or 3.5% degradation. Happy I didn't get a refurbished pack with more than 10% lost.

How did you get a replacement battery pack?

Warranty replacement. Low voltage on string, would shut down car. Had to tow it to dealer 3 times. Took to dealer 5 times over two weeks they cleared errors and would send me on my way but next day when trying to start it wouldn't start with EV system error.

 

[shikataganai]

Another datum:

2012. 35.4k Miles. Lived in Denver since 2015 and about 22k miles. Perhaps used Extended charge a half dozen times since I bought it (at 22k miles).

132 miles after balancing overnight. 90.4%. I was hoping for a bit more based off of others’ results but that’s what it showed.

 

[jimbo69ny]

Another datum:

2012. 35.4k Miles. Lived in Denver since 2015 and about 22k miles. Perhaps used Extended charge a half dozen times since I bought it (at 22k miles).

132 miles after balancing overnight. 90.4%. I was hoping for a bit more based off of others’ results but that’s what it showed.

10% over 22k miles isnt wonderful but it could be worse if it were left fully charged unused. The Rav only has battery temperature management if it is on or charging. I would've preferred that it was higher but I honestly expected it to be a little worse.

 

[a_mcclure]

Adding a data point, but also have a couple of questions. Purchased a 2014 Rav4 EV from original owner; approximately 32,000 miles. Did the Tony test and was a little disappointed that it came in at 130 or about 89%.

Can someone clarify about the battery and ambient temperatures comment? Is the overnight step the one that allows the cooling, or are the steps indicating that one should charge using extended charge, THEN allow it to sit and cool (then I assume try to charge some more) -- all before the overnight step? I did something in between, I suppose. Charged to standard level, then let sit for a few hours, then charged to extended level in the evening before disconnecting the battery and allowing it to sit overnight. Any insight would be appreciated.

Separately, I wonder if the following would be an advisable charging regimen:
- each night determine how much driving might be done the next day, including a cushion
- set the departure time for the next day late enough to accomplish the target level of charge in time for the REAL intended departure time
- plug in at night, then just unplug the next morning when it's time to leave even though charging is in progress

So if the car says it needs 3.5 hrs to charge to full, but I only want to charge it 2 hrs overnight, I would just set the departure time for 1.5 hrs after my intended departure time. Is it worth the effort, or is it not going to help the battery life any more than just charging to standard "full" level every time I feel it needs to charge? Is it a BAD idea to be regularly unplugging when the car is in an active charging mode?

Thanks in advance for any tips!

Andy McClure
2014 Toyota Rav4 EV #3304, Blizzard Pearl
2017 Chevy Bolt Premier
Clipper Creek 24 Amp L2 EVSE