Anyone know how to disable bms

[REFLECTIONxRAGE]

How do you disable bms to force the alternator to charge all the time like a traditional alternator does to have 14.6 volts all the time upgrading to dual batteries and need to disable bms to keep both batteries fully charged for sound system and winch overlanding gear

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[VRFlyer]

The old way was just to unplug the BMS module, this was for 12th Gen. I don't know if this is still a trick thing.

 

[Buyer2021]

unplug the BMS module

Also known as "Battery Monitoring Module "A", disconnection will likely yield a number of DTC's on the Gen 14 (and likely won't accomplish what the OP seeks).

Attached FYI, essentially the same for 5.0 V8

 

[SilverPigeon]

There is also this post from @Hyins that I'm yet to try: https://www.f150gen14.com/forum/thr...ge-how-to-power-accessories.13862/post-452723
I've still got my crappy H6 battery, so I've got nothing to lose ?

 

[Rineland]

There is also this post from @Hyins that I'm yet to try: https://www.f150gen14.com/forum/thr...ge-how-to-power-accessories.13862/post-452723
I've still got my crappy H6 battery, so I've got nothing to lose ?

@REFLECTIONxRAGE I would also suggest these changes. I made them months ago and have not experienced any negative effects. A year prior to making these changes I upgraded to the H8 Everstart Platinum AGM (I believe initially recommended by @Buyer2021 based on some very sound logic). That post links to how SRC works and I was witnessing the charging during deceleration events in real time with the ANCEL BM200 monitor. I thought it was weird that the charging system would spike in voltage every time I slowed down to brake for a turn and went looking for answers and stumbled upon that post. I was also not happy that my new AGM would typically rest in the low 12.0V range. Since making the change, my battery sits around 12.5-12.6V, even after days of not driving it. It’s been parked for two days (and it’s been cold in the low 20s at night) and it’s currently sitting at 12.5V. Shortly after starting, the voltage climbs right up into the high 14V range, which is great for the short trips I make. On longer drives I have checked voltage towards the end and it does settle into the low 13V range, right where you’d expect a float charge to be. My impression from the data I’ve reviewed after these changes is that the charging system better handles short drives to actually charge the battery while still keeping tabs on it and backs off so as not to overcharge it.

 

[SilverPigeon]

Gonna grab my lappy and mongoose right now... ?

 

[REFLECTIONxRAGE]

Gonna grab my lappy and mongoose right now... ?

Let me know how it goes if you can do a video on it I'm not the best at instructions on paper lol

 

[Buyer2021]

There is also this post from @Hyins that I'm yet to try: https://www.f150gen14.com/forum/thr...ge-how-to-power-accessories.13862/post-452723
I've still got my crappy H6 battery, so I've got nothing to lose ?

FYI / FWIW, referring to info at that link, here's what I found as OE and the one item (TargetSOC) I changed when I went from the OE H6 to the H8 Everstart on my 2022 3.5EB Lariat. I did not / do not want my SOC target any higher than 90% in order to meet a balance between maintained battery level and long-term battery life (YMMV).

I made the Target SOC change on the BCM 'Plain English' (aka 'Easy Method') screen in FORScan where I had the choice of 80% (enabled by default) or enabling 90%. Above shows the parameter values changed by that method.

Now 17 months on the H8 with the change shown above, all is great AFAIK (I've never seen any hint of low-battery issues or warnings).

 

[REFLECTIONxRAGE]

@REFLECTIONxRAGE I would also suggest these changes. I made them months ago and have not experienced any negative effects. A year prior to making these changes I upgraded to the H8 Everstart Platinum AGM (I believe initially recommended by @Buyer2021 based on some very sound logic). That post links to how SRC works and I was witnessing the charging during deceleration events in real time with the ANCEL BM200 monitor. I thought it was weird that the charging system would spike in voltage every time I slowed down to brake for a turn and went looking for answers and stumbled upon that post. I was also not happy that my new AGM would typically rest in the low 12.0V range. Since making the change, my battery sits around 12.5-12.6V, even after days of not driving it. It’s been parked for two days (and it’s been cold in the low 20s at night) and it’s currently sitting at 12.5V. Shortly after starting, the voltage climbs right up into the high 14V range, which is great for the short trips I make. On longer drives I have checked voltage towards the end and it does settle into the low 13V range, right where you’d expect a float charge to be. My impression from the data I’ve reviewed after these changes is that the charging system better handles short drives to actually charge the battery while still keeping tabs on it and backs off so as not to overcharge it.

Wouldn't this not disable bms but just increase soc target?

 

[Buyer2021]

Wouldn't this not disable bms but just increase soc target?

correct

 

[SilverPigeon]

The main reason I just made the changes was to try to get a better resting voltage; even after a long trip, the dashcam often won't go into parking mode with its voltage cutoff set at 11.8V. I have always been experiencing the same low 12v range through monitoring, even though the battery tests fine. If I can get the dashcam to go into parking mode consistently for a minute while I hook up the charger, I'll be happy. I'll be doing a 8.5 hour drive tomorrow and then back again on Sunday so I'll report findings.

Meanwhile I did some video; bear in mind it isn't quite Steven Spielberg quality or production values? I'll put them up asap.

 

[SilverPigeon]

@REFLECTIONxRAGE: I missed editing the actual asbuilt numbers but just change them as per the values listed in the post I referred to earlier. If you change %SOC in easy mode, then go into asbuilt mode and then do a "save all" to make a backup before you change the asbuilt values. Then you can change the 726-07- values and just hit the "write" next to the 726-07- values. Then do a "save all" down the bottom to make sure you have a backup Of your modifications.

 

[REFLECTIONxRAGE]

The main reason I just made the changes was to try to get a better resting voltage; even after a long trip, the dashcam often won't go into parking mode with its voltage cutoff set at 11.8V. I have always been experiencing the same low 12v range through monitoring, even though the battery tests fine. If I can get the dashcam to go into parking mode consistently for a minute while I hook up the charger, I'll be happy. I'll be doing a 8.5 hour drive tomorrow and then back again on Sunday so I'll report findings.

Meanwhile I did some video; bear in mind it isn't quite Steven Spielberg quality or production values? I'll put them up asap.

I changed bms percentage from 80 to 100 in easy mode so do I need to set as built to 100 as well? I'll be looking for your updates

 

[SilverPigeon]

I changed bms percentage from 80 to 100 in easy mode so do I need to set as built to 100 as well? I'll be looking for your updates

No, that easy mode setting changes the asbuilt values. I've set exactly as the referenced post to see what happens: SOC 120%, regen off, refresh on. Will report back after the weekend ?

 

[SilverPigeon]

Ok, after two 8.5 hour drives, setting SOC to 120 as per the referenced post makes the BMS stop charging at 80%. Probably don't want to go higher with an AGM, but the actual value can be set as high as 200% ?‍ stays in conventional charging, never saw any refresh mode.

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