Ford BMS issues, research, testing, and solution results

[Porpoise Hork]

I have thought about this but it’s over my head in how to make it all work together.

Shouldn't be too hard to run a set of cables to the rear seat for a 20-30 AH aux battery. There's a relatively inexpensive kit available to do just this very thing and looks pretty straight forward to install it but not sure if it would work on the 14th gen non-hybrids. Might be worth asking them about it.

https://www.dfna.info/product/f150-dual-battery-kit/

Sponsored

 

[Mosey]

I haven't seen those graphs in SOC vs voltage before. Interesting.

I purchased the upgraded BM300 Pro monitor.

I really wish it was CarPlay compatible.

 

[Ricksc]

Shouldn't be too hard to run a set of cables to the rear seat for a 20-30 AH aux battery. There's a relatively inexpensive kit available to do just this very thing but not sure if it would work on the 14th gen non-hybrids. Might be worth asking them about it.

https://www.dfna.info/product/f150-dual-battery-kit/

Picking up my new free battery after work. If the draw has been fixed by new battery I may order that kit looks pretty simple.

 

[Porpoise Hork]

The only thing that might be a potential snag is finding out where to connect the aux 12v + accessory lead to so it can feed power to the system when the key is off. One would hope they provide instructions for this.

 

[Snakebitten]

If the auxiliary battery is connected through a simple parallel configuration, it's no different than the Powerboost except during engine start events. That's the only time the battery isolator is an open circuit on the Powerboost. When the Powerboost is parked, the auxiliary battery and underhood battery are connected no differently than the proposed addition of an auxiliary battery to a non Powerboost or ProPower F150.

Note there are non Powerboost F150s with auxiliary batteries under the passenger rear seat.

 

[Ricksc]

Back on charger. When auto store test and it has good cranking amps and good voltage they will not replace battery do to SOC. I have 3 more months for free replacement so they told me look online how to kill a battery. Downloading new forscan so can reset BMS on computer see if it works

 

[Porpoise Hork]

High heat with frequent deep discharges below 50% SOC then charging with the wrong strategy usually does the trick on AGM type batteries.


Or so I hear.

 

[Ricksc]

I just want this f…… issue fixed. Worst case kill battery and start over. Auto store guy told me battery reps are getting stricter on replacements.

 

[Porpoise Hork]

Crap like this is why I miss old school flooded cell batteries and basic charging systems. Why Ford feels compelled to have 15 different computers just to handle something (and fail at miserably at it) when a simple $5.00 alternator voltage regulator handled it perfectly for 50+ years is beyond me.

Is the 12v battery low?
Yes.
Alternator charges it up in about 10 minutes...
Done...

How friggen hard is that?

 

[Ricksc]

Ok charged battery tried BMS reset with lights and brake taps no go. Waited a hour on charger used forscan and BMS reset. Now just to watch battery monitor see what happens.

 

[Ricksc]

If the auxiliary battery is connected through a simple parallel configuration, it's no different than the Powerboost except during engine start events. That's the only time the battery isolator is an open circuit on the Powerboost. When the Powerboost is parked, the auxiliary battery and underhood battery are connected no differently than the proposed addition of an auxiliary battery to a non Powerboost or ProPower F150.

Note there are non Powerboost F150s with auxiliary batteries under the passenger rear seat.

Do you know what type and size the powerboost aux battery is? Seems like this would be the fix or at least worth the try for us that don’t drive far.

 

[Porpoise Hork]

The OEM aux battery "24-2295" or BHAGM-AUX1-A is relatively tiny at just 7.5 AH capaccity. I have not found a direct non Motocrap battery that matches the same size but the Mighty Max Battery YB12A-A is a 12 AH AGM fits very well with minor modification to the Aux battery tray. For the 20-30AH lithium batteries most of us are wiring them in parallel to the stock aux battery and putting it in the large storage tray next to the aux battery.

You can also shoehorn in the 14AH Super Start Power Sport AGM Top Post Battery Group Size BTX14AH 220 CCA - ETX15 but the aux battery cover won't sit flush with this one.

 

[Ricksc]

I may look under the hood to see if I can get it in. Being a eco boost might be easier under hood. Will wait and see how this goes after the charge and BMS reset. First time I see blue on battery monitor as it sits

 

[Snakebitten]

Some of us replaced the little auxiliary AGM with a cheap LFP with its own built in BMS.
Keep in mind that it could be in issue for folks who have trucks in the frigid tundra. These cheap Chinese LFP batteries do not have onboard heaters.

I have this one:

 

[Ricksc]

Been sick for the last couple days battery voltage stays around 12.4 SOC dropped to 51%. Did the draw test with truck sleeping, 16.4mA. Well with in the range. Think I will look for a graphing meter and hook up all night see if it changes. Unless the battery is just bad no other ideas.

Sponsored