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I put a new battery into ours a couple of years ago. I didn't reset any BMS. It's running fine. I'll defer to more knowledgeable folks on this, but I thought the idea of a BMS was to shut down peripheral systems if there was a detected degradation of the battery...or also the charging system? If that is the case I would hope they designed the logic to measure degradation based on the battery's condition not it's age. For example....when engine is running what volts are delivered to the battery? when ignition key is turned on and before engine is cranked, what is the standing voltage of the battery? when engine is cranking what is voltage drop and current draw across the battery. Set all these values against specs in the vehicles electronics and activate BMS or ECL if and when necessary. I don't think I would be looking at whether the battery is 1 day old or 10 years old.
I wonder how many Auto Zone, OReilly stores etc know how to reset a BMS as and when they replace a battery? By now there must have been many customers who've had battery's replaced by the auto stores over the years.
 

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This might be the BMS reset procedure for cars without rear fogs. Found in an Amazon review of all places. If the link below dies someday, the “manual reset” instructions were loaded in an aftermarket reset scanner that gave instructions for cars with and without a rear fog light button.

Amazon



The procedure for cars WITH rear fogs is the same as Bud Bundy posted earlier, except Bud had an added a step after #1 saying the dipped beams need to be on. So maybe that needs to be in there?
Sorry for digging up this thread, but the method provided for US Spec Foci works flawlessly, at least it did for me. Turn key to ignition (don't start the engine)->flash your high beams 5 times->fully depress the brake pedal 3 times (I held it after that)-> wait around 15 seconds, and the battery light should flash 3 times. This is for future reference. THANK YOU @E365/5
 

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Sorry for digging up this thread, but the method provided for US Spec Foci works flawlessly, at least it did for me. Turn key to ignition (don't start the engine)->flash your high beams 5 times->fully depress the brake pedal 3 times (I held it after that)-> wait around 15 seconds, and the battery light should flash 3 times. This is for future reference. THANK YOU @E365/5
What year Focus do you have? I will be attempting this on my 2016 in the coming week and will also include my experience for future reference.
 

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What year Focus do you have? I will be attempting this on my 2016 in the coming week and will also include my experience for future reference.
I have a 2014 pre-facelift SE. Crossing fingers it works for post-facelift Foci as well. Good luck!
 

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Alright, great news US Focus owners. The method shared by @E365/5 seems to have worked flawlessly for me on my US 2016 Focus. I followed his directions which had to be done within 10 seconds: Ignition on, flash high beams 5 times, and then fully depress the brake 3 times and leaving my foot on the pedal fully depressed on the last press. About 10 seconds after I finished that sequence, the battery icon on the dash flashed 3 times which, from reading this entire thread and watching some videos on youtube, I believe means the BMS is reset . Also from reading this entire thread, there doesn't seem to be a way to check if the BMS is actually reset so I hope the battery icon flashing 3 times actually means that it was reset. I am very happy that I do not need to spend more money on the tool and I assume many others will be happy to figure this out as well.
 
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