bad battery repair

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Joined
May 12, 2024
Messages
17
Location
williams az
I bought a 2014 rav 4 near phoenix az. before i bought I test drove it and it ran fine. i took it to a blink charger plugged it in with the 2 lights lit up in the back window and it took a charge just fine. But after I got my new rav 4 home in Williams near, Flagstaff, we had a snowstorm. The rav 4 would not take a charge any longer. I had AAA tow it to 2 different Toyota mechanics asking them to replace the big fuses I had read about here on this forum blowing "being 90% of the charging problems" with the evs. The Toyota in Surprise Az said it was not the fuses but error code BMS F003 BATTERY INTERNAL FAULT and BMS F097 BATTERY CELL UNDER VOLTAGE. Does anyone on this forum know were i can bring my rav 4 to get the battery cell repaired? I'm in Northern Az and I can tow it to a repair facility or if there is a mobile mechanic that could come to az?
 
Your traction battery probably has internal water damage. The change in weather probably caused internal condensation to move the moisture around and surface a new failure mode.
Repairing the traction battery is unlikely to be possible or durable. Your best bet is to find a battery pack in working condition from a car that otherwise undriveable or salvage. Someone may be able to make use of some of the modules from your failed pack, so it does have some salvage value.
There have been many attempts to repair Tesla battery packs by replacing modules. The problem is that people don't do well instrumented tests to determine the capacity of the modules in the pack and locating a closely matched module to replace failed ones. The battery goes out of balance relatively quickly because of the mis-match and then needs another repair or complete pack replacement anyway.
 
Also, while the non-charging issue that is the OBC's AC input fuses is a relatively cheap fix, you're not going to find any Toyota mechanics that will do the job; it's an EV repair, not a Toyota repair (the part is a Tesla part). If you've read any of the OBC fuse replacement threads, you'll see it's not just "change fuses"; I took 12 man-hours to do mine.
 
Your traction battery probably has internal water damage. The change in weather probably caused internal condensation to move the moisture around and surface a new failure mode.
Repairing the traction battery is unlikely to be possible or durable. Your best bet is to find a battery pack in working condition from a car that otherwise undriveable or salvage. Someone may be able to make use of some of the modules from your failed pack, so it does have some salvage value.
There have been many attempts to repair Tesla battery packs by replacing modules. The problem is that people don't do well instrumented tests to determine the capacity of the modules in the pack and locating a closely matched module to replace failed ones. The battery goes out of balance relatively quickly because of the mis-match and then needs another repair or complete pack replacement anyway.
I ve watched gruber motors down in Phoenix test, locate then remove and replace the bad cells on the tesla model s . It looks like a fairly easy process with proper tools. I have a 2007 Toyota prius also . It has bad cells also but it still drives fine. I see people advertise that repair the bad cells on the prius and Lexus hybrids opposed to replacing the complete battery. My friend replaced his complete prius battery for 3000k . He get 5 more mpg . I'll keep my dead cells at that price . Is there a way to still charge my rav 4 with a few bad cells? I see those old Nissan leafs with depleted battery's run around only charging up to 20 miles. Can I override my rav4 default that won't let me charge and charge it with the dead cells still in parallel like the leafs?
 
We were talking or someone referred you to me because I've herd about this. I'm in Surprise, and we're the ones who pioneered cell level repairs - before Gruber. We regularly repair MS batteries with good results and can do the RAV4 also. Charger repairs too.
 
I ve watched gruber motors down in Phoenix test, locate then remove and replace the bad cells on the tesla model s . It looks like a fairly easy process with proper tools. I have a 2007 Toyota prius also . It has bad cells also but it still drives fine. I see people advertise that repair the bad cells on the prius and Lexus hybrids opposed to replacing the complete battery. My friend replaced his complete prius battery for 3000k . He get 5 more mpg . I'll keep my dead cells at that price . Is there a way to still charge my rav 4 with a few bad cells? I see those old Nissan leafs with depleted battery's run around only charging up to 20 miles. Can I override my rav4 default that won't let me charge and charge it with the dead cells still in parallel like the leafs?
Prius NiMH packs are completely different than the lithium batteries in Teslas. The fact that it's hybrid also mitigates the situation because the engine runs frequently, masking many problems in the battery.

The Leaf generally has uniform capacity degradation, not imbalance problems, although that can happen too. Finding a leaf module (2S2P) that has exactly the same degradation profile as your existing pack is pretty difficult. The mechanical replacement of the module is super easy, but finding a module that will stay balanced with the rest of the pack is pretty hard. You would have to have a library of instrumented cells to pick the one that closely matches the pack.
 
I wish the Avondale service manager had told me about you when i had my rav4 down there in the valley. I'd like to have you repair if possible. The Gruber motors said they only work on model S and the Avondale service manager said to call around California Toyotas for service.
 
Also, while the non-charging issue that is the OBC's AC input fuses is a relatively cheap fix, you're not going to find any Toyota mechanics that will do the job; it's an EV repair, not a Toyota repair (the part is a Tesla part). If you've read any of the OBC fuse replacement threads, you'll see it's not just "change fuses"; I took 12 man-hours to do mine.
Toyota service told me they could do the fuse swap . That is why I had the car towed there.
 
Then they lied. Toyota techs will not open the OBC, to replace fuses, nor will they un-glue the DC-DC to replace the cabin heater fuse.

They will replace the fuse on the Service Disconnect under the passenger seat, as that has a Toyota part number, but the other fuses are in non-serviceable parts, from their perspective.

They'll also agree to replace the OBC as a single part, but wait times for replacement units from Tesla vary.
 
Prius NiMH packs are completely different than the lithium batteries in Teslas. The fact that it's hybrid also mitigates the situation because the engine runs frequently, masking many problems in the battery.

The Leaf generally has uniform capacity degradation, not imbalance problems, although that can happen too. Finding a leaf module (2S2P) that has exactly the same degradation profile as your existing pack is pretty difficult. The mechanical replacement of the module is super easy, but finding a module that will stay balanced with the rest of the pack is pretty hard. You would have to have a library of instrumented cells to pick the one that closely matches the pack.
Unfortunately in RAV4EV, Tesla provided only replacing the HV Battery* for a malfunction with code BMS_f097 https://alflash.com.ua/2019/to_rav4ev/bms_f097.pdf and there is no test plan
https://alflash.com.ua/2019/to_rav4ev/003_097_1.jpg
003_097_1.jpg


I suppose it would be useful to first check the cells voltage spread in a relatively simple way using a smartphone
https://alflash.com.ua/2019/to_rav4ev/bat_data2.jpg

* https://alflash.com.ua/2019/to_rav4ev/bmbdm3.jpg
 
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Then they lied. Toyota techs will not open the OBC, to replace fuses, nor will they un-glue the DC-DC to replace the cabin heater fuse.

They will replace the fuse on the Service Disconnect under the passenger seat, as that has a Toyota part number, but the other fuses are in non-serviceable parts, from their perspective.

They'll also agree to replace the OBC as a single part, but wait times for replacement units from Tesla vary.
Dealership service centers can vary widely. I had one dealership source reman parts for my Prius when generally you might expect them to be unwilling. Tony Williams was able to get a few of the local Toyota dealers to agree to partially remove their JDemo system when doing other repair work, by supplying detailed instructions, so that owners wouldn't have to have Tony remove it, then put it back in those situations.

It's entirely possible that an individual service dept might be willing to change the fuses, especially given clear instructions. I'm sure they'd likely refuse to warranty the repair, but it's not impossible.
 
Do you have numerical values of the cells voltage measurement results in the form of a table or txt file?

See attached text file of decoded brick voltages, as well as raw CAN data if you'd like to confirm my math :) Unfortunately this forum does not allow spreadsheet file attachments...
 

Attachments

  • RAV4 EV battery brick voltages.txt
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See attached text file of decoded brick voltages, as well as raw CAN data if you'd like to confirm my math :) Unfortunately this forum does not allow spreadsheet file attachments...
I have numerical data on the battery cells voltage of several RAV4EVs and now with your help I have added the collection :)
Thank you for your attention to my request!
The data was received via the CAN bus directly from the BMS through the blue diagnostic connector, right?
 
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