Parasitic Draw "Solution" - Install a 12v battery disconnect switch?

[MakinDoForNow]

Interesting... will look into this... Thanx

It is logical, at least in my thoughts, that the ,up to 8 hour thing is that the bms will trickle charge the 12v and possibly perform a de sulphate, but most likely is just trying to determine what the max voltage the 12v will accept. Ford appears to not want to overcharge the 12v and if each time it's charged to 99.98% sooner or later it stopping at 80.0% probably thanks to some young whipper snapper programmer.

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[GPSMan]

Ya maybe.

 

[MakinDoForNow]

for my 3.x hour test with truck parked and "ready" the ScanGauge showed this:

14.6 volts and 0 amps flowing.
Sure. Ok. Fine. For nearly four hours.
Actual voltage measured at the see lbattery was even higher.

Seconds after turning the key off nets this confusing result:

And slightly higher here:

Then, turning on the headlamps nets:
(Might have been headlamps and more; I forget. But was just for a minute.)

and

Not sure what to make of this.
But does not make me feel like this is "healthy". Your take?

The following morning (you can tell ambient was 61 degrees also )

Interesting: in first pic scan have shows 70% soc. Where is scan gage getting 70% bms or probably a memory location that has not been updated and possibly was or is the trigger point soc at which some function will happen (I am ex programmer and can see multiple table items related to 12v soc) and is not the current soc. The voltage at 0 implies dcdc converter is furnishing current and 12v may be charged or too hot to be charged or? The voltage at 14.6 appears to be the 100% charge settled voltage and there probably has been no charging for 45-60 minutes maybe more. Since you show 14.99v at the battery I assume that the dcd converter is still active. The bms is attached to the neg battery post and will control charging from there. (I know not how). If you wait for the dcdc timeout you would read the battery at 12.6 LESS WHATEVER IS DRAWING CURRENT AS YOU WILL BE TAKING AN OPEN CIRCUIT READING. The 12.2 and 12.3 reading are just different devices and maybe at different lengths of wire to ground.
The 11.7reading is because of the 33 amp draw. The 12.07 reading is probably closer to the battery and again open circuit readings at different points.
The following morning. The 12v soc at 65 implies that 5 have been used of the 70 (whatever that means) the truck had a snack of 5 which is reasonable. Ok a thought "it is logical that if the 12v will be disconnected (aaarrrggghhh= DEEP SLEEP) at an soc of 30% the 70 and 65 field readings is the soc countdown switch off at zero and is in computereasy "if soc countdown equal 0 perform DEEP SLEEP routine". Any how that's a thought. Put a volt meter in cig style plug and read battery open circuit reading with key in accessory position before turning to run. I do believe in a post you said was in 11.xx range. I do think there is something wrong happening which will be found.

 

[Dad]

Hello,

I recently experimented with disconnecting my 12v battery's negative terminal while out on a camping trip. I brought my Hulkman 2000A jump starter, 2 Amp battery maintainer + my portable battery pack (Ecoflow River) as a precaution. However, when getting in and out of the car repeatedly, I got worried about my battery drain and just disconnected my negative terminal under the rear seat. I did this each night of the trip and it worked well.

Side-Effects? None (thus far lol)

I was worried about my computer reset, but at least for now, I didn't notice anything different. Not that I care - but my radio presets, Bluetooth to my phone, current mpg / odometer, etc. - they all returned to normal each time.

However, I think an easier work around would be to just install a battery disconnect switch. This would free me up from having to pull out a wrench and remove the terminal post each time I need to disconnect / reconnect my battery every time.

Has anyone else done this yet? I don't plan on disconnecting the 12V (-) unless I'm out in nature, away from an outlet to keep my battery maintainer, this is only for when I have no better option and can't risk getting stranded in the middle of nowhere. What do you guys think of this? Something like a knife-blade disconnect switch like this(?)

I had a battery disconnect switch installed on my 2018 Chevy Colorado for flat towing. Truck caught fire before I was able use it, but that should work with the Maverick. Got it either from eTrailer or Roadmaster people.

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