Interesting post... but why would I want/need to reset this?

 

You need to do it after you replace the battery or you'll kill the new one.

 

So, this is like the oil change reminder?
How would the car kill a new battery?

 

In brief, the BMS is tracking your battery state of charge and age. If you don't reset the BMS, it will hold the old battery parameters and treat the new battery like an aged battery. This may lead to situations of insufficient charging, which can then lead to decreased life of battery.

 

There are some things that do not need technology. SLA batteries should not be one of them.

 

We have AGM batteries in our cars, at least from the factory. AGM batteries are sensitive to over and undercharging, which is why I put the charger on the car once a week or if I know that it will sit for a few days.

Beats prematurely buying a $300 battery!

 

Where is this written ref the BMS?...Thanks

 

Here's the BMS reset reference in the RS Workshop manual:

 

Start stop cars use AGM batteries. AGM is also in the part number for our batteries

 

Here's a good write-up on AGM. My Focus ST has BMS as well (and no AGM from what I can tell), so it's not exclusive to AGM. What is an AGM battery? | Greenlight by Interstate Batteries

 

Thanks.....@#$%^&*7.....smh

 

None of the secret cheat code combos worked for me either. Luckily Forscan will allow resetting the BMS with a standard license. My trial extended license expired, and they weren't selling the extended license when I was doing this (on the 4th).

 

Excellent post thanks turbojr74. When using Forscan did the battery lamp flash to confirm BMS reset?

Also adding that Forscan Lite on iOS has both BMS reset and TPMS training request functions (plus more). I have not used them yet to confirm they work, but I'd be very confident.

 

yes battery lamp will flash when it’s successful.

 

There's probably a way to check battery age on FORScan. That's a way to know for sure.

@morbid you don't have to pay for an extended license, just have to renew it all the time.

 

You guys will get a laugh out of this. I called in to my local Ford Dealer Korum ford in Puyallup, WA to get a price quote on them putting in the battery. That way I wouldn't have to mess with the BMS reset. The service advisor told me that she's never heard of the BMS and she needed to check with the shop foreman. The shop foreman told me to just by a battery at Costco and unplug for 10min or more the old one that would reset the BMS system. I got a laugh out of it as I'm sure the RS isn't the only Ford with this set up.

 

I’m in Puyallup @flyingcesar and could help if you need. I would recommend staying away from Korum (long stories).
While it’s more of a drive, I’ve had great service as Scarff Lincoln Ford in Kent. Talk with Gary there. Great guy.

 

@turbojr74 I ordered a OBII cord and will download FORSCAN. Figured with the money saved from going to the Stealer might as well give a go my self. I'll definitely reach out to you if I hit a roadblock. Thank you for the recommendation ill start dealing with Gary.

 

BMS reset? Sorry? I have disconnected my battery countless times and haven’t had to reset anything, ever?


Sent from my iPhone using Tapatalk

 

BMS reset? Sorry? I have disconnected my battery countless times and haven’t had to reset anything, ever?


Sent from my iPhone using Tapatalk

I think you missed the bit, where it says you need to do this if REPLACING the battery for a new one?

 

I wondered that too. This cleared it up, for me. (same battery)
Reset BSM (Battery Monitoring system)

 

The BMS reset not being done isn't a big deal in reality. The prime reason for the BMS system is for fuel economy. The system can track the condition of the battery more accurately and minimise the charge rate out of the alternator for the purpose of saving fuel. It is also there to manage load shedding if the battery condition drops to a pre determined level, so for example the audio system will be dumped if the battery level/voltage gets too low.
You dont think when the vast majority of people that get the local battery shop to fit a new battery the guy does a BMS reset do you. More a nice to do thing I think. I wouldn't be losing sleep over not doing it.

Ciao

 

dupe

 

I got lucky the headlight flashing 5x and brake pedal 3x worked for me...well the battery indicator did flash..

 

Can anyone else confirm this?

I will add it to the first post.

 

I changed the battery today. Just confirming that Forscan Lite v1.5.9 on an iPhone iOS v14.2 appeared to reset the BMS successfully. The battery light flashed two or three times after selecting the BMS reset service item and hitting the 'play' button in Forscan, and then agreeing to the scary warning. It took a few seconds before the battery light flashed, so its worth pausing at that point to wait for it.

 

@Alpha Dog great news Mate - thanks for the confirmation. I’ll add it to the top.
What ODB II unit did you use or was this just a general BT connection to the RS in ForscanLite?

 

Thanks @big jim @GmpaJimj for the confirmation! I'll add it to the top

 

Oh so now you are a believer...lmmfao...its all good turbojr74

 

I bought a "Soliport ELM 327 Bluetooth OBDII OBD2 Diagnostic Scanner" in 2013 for $12 that I can't even find the link to buy one for anymore. Somehow that still works fantastic for everything I need. The bluetooth seems to connect perfectly from my PC in my office to my garage as well. I can't find it when it's parked in my driveway, but somehow the signal reaches reliably in the garage.

I plug my car into the battery charger and try my best to brick it, but so far I've yet to permanently damage anything. You'd think eventually I'd have all the options set how I like, but I can't help myself.

 

Hmmmnn...I thought I was being funny...I'll keep my day job

 

This is something I've been wanting to try since this thread appeared. But my RS has been down for 5 months waiting for a new RDU.

My Ford dealer, who have done excellent work on my early 2016 RS over the years, replaced my original battery with an OEM replacement during some other service work on 1/23/2019 at 55k miles. From what I've seen they did not reset the BMS, probably not knowing it even had BMS, which I wasn't aware of either. I had them replace it as the Battery State of Charge (SOC) on the original had started to consistently drop and charging it back up with a battery charger wasn't helping. Battery SOC had always run about 80% or higher. Prior to the replacement it was running below 60%. After replacement it was back above 80% and I stopped paying attention to Battery SOC until after the recent RDU replacement.

The car now has 64k miles on it. During the down time I did put a trickle charger on the car frequently (the dealer had me pick up the car while we waited for the RDU so it just sat in my garage). After the RDU replacement I noticed the Battery SOC, which I was worried about again with the down time, would not go above about 55%. The charger would appear to be charging the battery, starting at about 10amps and dropping to near zero. But the Battery SOC would read only 58% at best.

So I just did the reset. I used the 5x flash HLs, 3x Brake pedal method. It worked but for me I had to wait about 10-12 seconds before the battery light flashed twice, not 2-3 seconds, so be patient. When I checked the Battery SOC it was at 65%. Better but not what it should be. So I power cycled and checked again - 89% Battery SOC. I now think I'm getting a correct reading.

 

I have to agree with you, waited 10 secs approx and only flashed twice.

But it does work.

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I changed the battery with one from autozone in Oct 2019. believe it was a duralst. i wss not aware of this reset but have had no issues