Disabled the stop/start

[colinl]

If you disconnect the BMS ammeter on the battery negative terminal it disables, although it results in a Charging System Malfunction pop-up every cycle.

Yes, it does, but to me that is no big deal. Hit the ok button and that goes away.

here's the problem:

the battery monitoring system is definitely used to determine whether the installed battery is flooded or agm, and how much charging voltage to use, and the state of charge to use. if you have an AGM battery it can hit 15.2V (Ford believes) safely, but if you have flooded it maxes out at 14.4v when charging.

I don't know what it does with charging voltage when the BMS is unplugged or otherwise non-functional, but personally I don't want to find out by way of a dead battery. Overcharging a 12V car battery kills it way faster than undercharging.

I recommend you reconnect it and do one of the following (all of which were already suggested in this thread):
- push the button to disable autostop every time you start the engine.
- disable it with Forscan (easily found searching)
- disable with with an autostop eliminator ($100 and 5 min install)
- disable it with a tuning device such as SCT, accessport, or livernois

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[shrek]

here's the problem:

the battery monitoring system is definitely used to determine whether the installed battery is flooded or agm, and how much charging voltage to use, and the state of charge to use. if you have an AGM battery it can hit 15.2V (Ford believes) safely, but if you have flooded it maxes out at 14.4v when charging.

I don't know what it does with charging voltage when the BMS is unplugged or otherwise non-functional, but personally I don't want to find out by way of a dead battery. Overcharging a 12V car battery kills it way faster than undercharging.

I recommend you reconnect it and do one of the following (all of which were already suggested in this thread):
- push the button to disable autostop every time you start the engine.
- disable it with Forscan (easily found searching)
- disable with with an autostop eliminator ($100 and 5 min install)
- disable it with a tuning device such as SCT, accessport, or livernois

Meh, Its his truck. Let him screw it up if he wants to. No skin off my nose. FORSCAN is the easiest and cheapest in my opinion. Yup; I know its like an @$$hole, everyone gots one.

 

[Darnon]

if you have an AGM battery it can hit 15.2V (Ford believes) safely, but if you have flooded it maxes out at 14.4v when charging.

FWIW I didn't find setting it to SLA limited voltage <15V.

 

[Bill Quattlebaum]

here's the problem:

the battery monitoring system is definitely used to determine whether the installed battery is flooded or agm, and how much charging voltage to use, and the state of charge to use. if you have an AGM battery it can hit 15.2V (Ford believes) safely, but if you have flooded it maxes out at 14.4v when charging.

I don't know what it does with charging voltage when the BMS is unplugged or otherwise non-functional, but personally I don't want to find out by way of a dead battery. Overcharging a 12V car battery kills it way faster than undercharging.

I recommend you reconnect it and do one of the following (all of which were already suggested in this thread):
- push the button to disable autostop every time you start the engine.
- disable it with Forscan (easily found searching)
- disable with with an autostop eliminator ($100 and 5 min install)
- disable it with a tuning device such as SCT, accessport, or livernois

It just makes me mad, that you have no option to leave this turned off. Also, why pay to disable something you didn't want to begin with? You make valid points and I may end up reconnecting it. It is a real pain remembering to shut it off every time you start the truck. The truck is still averaging over 29 mpg not using the stop/start.

 

[colinl]

The truck is still averaging over 29 mpg not using the stop/start.

mine is turned off, also.

I used Forscan, it is very easy. the adapter is like $50 bucks, which makes it about half the cost of using an autostop eliminator, plus you can do other things while you're in forscan such as disabling the double honk when exiting a running vehicle. (if I forget something inside my house and go back for it, I really don't enjoy getting honked at, LOL.)

 

[HeyBales]

It would be interesting to see what the likely fail-safe battery charging routine is though.
Like how many Amps is allowed to go to battery now?
Since it has no concept of battery SOC%, does it start with float charge, or a few minutes of full charge just to be sure?

Perhaps you'll get to experience just a touch of what the hybrid folks experience!

Interesting method to be sure.
Wonder how some of these others could be made to work to disable it. Of course winter time now perhaps easier on some.

The system does not stop the engine if:

• The driver door is open.
• Your vehicle is at high altitude.
• The heated windshield is on.
• The engine is warming up.
• The outside temperature is too low or too high.
• The battery charge is low.
• The battery temperature is outside the optimal operating range.
• The engine is required to run to maintain interior climate and reduce fogging.

 

[Rwills]

I decided to disconnect this feature. I know some will say it was a mistake, but it is so nice to drive the truck now.
I know that it also disconnects the battery management system. I can just reconnect the sensor if needed.

Did you notice your battery overcharging after unplugging? I thinking if unplugging. My wife travels on 3 miles to work and sometimes it goes into battery saver mode because she doesn't drive far enough

 

[Cancunbadlands]

Did you notice your battery overcharging after unplugging? I thinking if unplugging. My wife travels on 3 miles to work and sometimes it goes into battery saver mode because she doesn't drive far enough

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Start stop eliminating device

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