Disconnecting the 12 volt battery does nothing to the main traction battery. It merely resets the crazy GOM. Trying to calculate EPA rated range minus something is NOT going to work!!!
Yes, you likely have 5-10% traction battery degradation, and the way to determine what that degradation is, is with the “Tony-Test”.
1) Fully charge the traction battery in EXTENDED mode
2) Make sure the car is unplugged
3) Disconnect all 3 black negative leads from the 12 volt battery (12mm wrench)
4) Let the vehcile sit overnight
5) Next morning, reconnect the 12 volt. You should get a spark.
6) Open the driver’s door and look at the GOM. Write the number down.
7) It will take two pushes of the start button to power up the car. Push once, and wait for the Navigation to spin up. Then push a second time, and you’ll hear the familiar “clunk” and see READY above the speedometer
8) The GOM is reset. The number you wrote down is then divided into 146 to get the approximate degradation:
Example: 132 / 146 = 90% capacity of the traction battery
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Replace the 12 volt battery now. Order the Bosch 12 volt that I recommend below. You can pick it up at Pep Boys, or they will ship it:
Rav4 EV 12 volt Battery recommendations:
Woke up to a dead RAV4 yesterday, the 12V was toast. Wouldn't even trickle charge. I bought the Bosch and replaced it. That's when all the problems started. At first, it wouldn't even slip into gear and I was getting all sorts of errors - EV System errors, airbag errors, power steering errors. After countless reboots, an hour on the J1772 charger, and more reboots, it finally returned to semi-normalcy and could at least drive it. But the EV System errors persisted, and this morning I took it in to the dealer.
Please, PLEASE, folks. Replace that original Toyota battery now... while this story is fresh in your mind.
You’re going to replace it anyway, and that replacement Bosch battery isn’t going to get any cheaper!
Please, stop the madness. Replace your Toyota battery, even if you’re too cheap or too lazy to do so.
Here are the recommended 12 volt battery specifications:
1) AGM (not flooded acid cells like the original)
2) Group 24F size
3) 60 amp/hour rating
YES, I RECOGNIZE THAT THIS IS NOT THE BATTERY or BATTERY SIZE THAT PEP BOYS OR TOYOTA RECOMMENDS ! INSIST ON GROUP 24F SIZE.
I DO NOT RECOMMEND ANY LEAD-ACID BATTERY FROM COSTCO, ETC. YES, I RECOGNIZE THAT THEY MAY BE CHEAPER.
https://m.pepboys.com/search/?term=bosch+24f+60ah+agm
Pep Boys # 0838890
Bosch S6508B S6 or Exide Edge FP-AGM24F battery with the correct specs is $150-$180. Units are built by Enersys.
Autozone also has a competing battery, built by Johnson Controls called Duralast Platinum for about $200:
https://www.autozone.com/batteries-starting-and-charging/battery/duralast-platinum-battery/547127_188710_25697
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What is lost and needs to be reset with a 12 volt disconnect:
http://www.myrav4ev.com/forum/viewtopic.php?p=20859#p20859
1) Stored radio / SiriusXM stations will remain, however your last station listened to will likely be gone
2) Cell phone pairings are not 100%, so I would check. i have had to delete my phone (and the car from my phone) and re-pair it
3) Map display mode
4) Volume of navigation voice notifications
5) Random play modes
6) Charge schedule will be retained, but it won't work without hitting the "SAVE" button on the previous screen
7) state selection from destination address page
