Toyota Rav4 EV Forum

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 Post subject: Re: How to Calculate Rated Range / Battery Degradation with
PostPosted: Fri Aug 26, 2016 6:53 am 
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Joined: Wed Nov 14, 2012 9:50 pm
Posts: 3861
Location: San Diego
rayray wrote:
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.


Quote:
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.


Quote:
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.


Quote:
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.


Quote:
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.


Quote:
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%.


Quote:
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? :P

Good luck with your RAV4 EV.


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 Post subject: Re: How to Calculate Rated Range / Battery Degradation with
PostPosted: Sun Sep 25, 2016 9:37 pm 
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Joined: Sun Sep 22, 2013 6:37 am
Posts: 20
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.


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 Post subject: Re: How to Calculate Rated Range / Battery Degradation with
PostPosted: Mon Sep 26, 2016 12:08 am 
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Joined: Wed Nov 14, 2012 9:50 pm
Posts: 3861
Location: San Diego
cooljw wrote:
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.


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 Post subject: Re: How to Calculate Rated Range / Battery Degradation with
PostPosted: Mon Oct 24, 2016 8:24 pm 
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Joined: Thu Jan 17, 2013 11:13 pm
Posts: 1591
Location: Los Altos, CA
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%

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2012 Shoreline Blue #1462 w/JdeMO | 4.32kW Motech/Enphase PV Solar | Leviton EVB40 40A & Jesla Home Charging | 2015 Limestone Gray e-Golf LE


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 Post subject: Re: How to Calculate Rated Range / Battery Degradation with
PostPosted: Mon Oct 24, 2016 11:56 pm 
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Joined: Wed Nov 14, 2012 9:50 pm
Posts: 3861
Location: San Diego
miimura wrote:
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.


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 Post subject: Re: Tony-Test: How to Calculate Rated Range/Battery Degradat
PostPosted: Mon May 01, 2017 12:27 pm 
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Joined: Sat Sep 14, 2013 3:09 pm
Posts: 110
Location: New Jersey
At 100k miles I see 135 rated miles (92.4%) thanks Tony.

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2012 Toyota Rav4 EV BLIZZARD PEARL #99, JdeMO Equipped
Purchased used in Michigan with 2700 miles, shipped to New Jersey on 10/13/2013


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 Post subject: Re: Tony-Test: How to Calculate Rated Range/Battery Degradat
PostPosted: Wed May 17, 2017 4:55 am 
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Joined: Sun Mar 03, 2013 2:26 am
Posts: 305
Location: Austin, TX
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.

_________________
Kohler Controller
Shoreline Blue
EVSE, AeroVironment 30A, 7.4kW
Reciever Hitch, CURT Class III Round Tube
Cargo Liner
Modified 120VAC EVSE to also accept 240VAC
Hood struts- Sokie Tech
JdeMO Level 3 Charging port
12.6kW PV system
VIN 1396
Austin, Texas


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 Post subject: Re: Tony-Test: How to Calculate Rated Range/Battery Degradat
PostPosted: Sat Jun 17, 2017 3:46 pm 
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Joined: Wed Apr 03, 2013 10:20 pm
Posts: 42
36.5K miles, 2012 model @ 98%.


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 Post subject: Re: Tony-Test: How to Calculate Rated Range/Battery Degradat
PostPosted: Tue Jul 04, 2017 4:02 pm 
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Joined: Fri Apr 19, 2013 7:12 am
Posts: 12
Location: Bay Area, CA
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 :D
Meanwhile, with 80 miles commute each day with this car, it doesn't miss a beat. Awesome EV experience!


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 Post subject: Re: Tony-Test: How to Calculate Rated Range/Battery Degradat
PostPosted: Sun Jul 16, 2017 7:44 pm 
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Joined: Wed Nov 09, 2016 7:07 pm
Posts: 43
Location: River Pines, CA
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.

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13 RavEV: 2263 Miles: 89,000 and counting w/ JdeMO


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