When to replace the aux batt and how to know?

[Ricksc]

I bet SOC will get you before that. 6 days SOC with no maintainer went form 80% to 60% causing the truck to go into sleep mode. Still had 12.4 volts.

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[Lefty665]

Mine commonly goes 6 days between uses, and occasionally longer. It has never had a battery issue. Charging voltage starts pretty high after that lack of use, often at 15v. Standing voltage drops to around 12.2v even after lengthy runs.

Funny variability on who runs into battery issues. Be great to figure out what the specific variables are.

 

[Davexxxx]

I bet SOC will get you before that. 6 days SOC with no maintainer went form 80% to 60% causing the truck to go into sleep mode. Still had 12.4 volts.

I'm interested to know what your monitor is measuring besides volts, to determine SOC, because none of the charts for AGMs, would put 12.42V @56%. More like 80%

 

[Ricksc]

Not sure how it reads that but I can say when truck is in sleep mode it works out to be low power in the monitor.

 

[Snakebitten]

I'm interested to know what your monitor is measuring besides volts, to determine SOC, because none of the charts for AGMs, would put 12.42V @56%. More like 80%

I do NOT pay attention to the SOC value on the Bluetooth voltometer. That thing is dead accurate for reading the voltage, but is all over the place for SOC.

I've seen it give a different (varying) SOC value for the same voltage, and the variance being 10% or more.

 

[Ricksc]

Biggest issue is Fords charge logic. If you produce something that takes more juice then it can produce in short distance, that’s the biggest failure.

 

[Davexxxx]

Just a note for any future update.

No notices or warnings since the one charge with the Genius 2D. Haven't been actively monitoring it but the welcome lighting has been working as normal.

I just adjusted my fog lights, which required the lights to be on for ~30 mins and decided to plug it in, just in case.

The light is slowly flashing red, which indicates a battery <75% SOC.

I'll sorta keep track of it until it goes to solid green and note about when that happens and the then resting voltage.

 

[Davexxxx]

Couldn't keep with the above post, because I had to use the truck before I could take the next set of readings. In any case the truck has been fine since. No warnings and everything works as normal. Truck last driven Wed. eve. 20 minutes out and back, of mixed city, back road, hwy.

Moving on, noticed that remote start and lock didn't work via Ford Pass but did with the remote.

On a hunch, decided to see if it could be battery related. Popped the hood last night, truck undisturbed since. Just took a V reading, finding 11.39. Obviously, an unfavorable state.

I didn't test it just now, before putting it on the charger but the truck has never failed to start. We'll see how long it runs to full charge and what happens after.

 

[Davexxxx]

It is now 55hrs. since I plugged it into the charger and is still flashing red.

I have to use the truck this eve and tomorrow, so won't be able to test things as I wanted to.

I'll unplug something over an hr. before I have to leave tonight, so I can get a resting voltage reading before I leave and depending on that, may try to start it with Ford Pass.

 

[Davexxxx]

12.5V. Still no lock or start on FP.

 

[flixden]

I connected a OBD2 adapter today and drove to work and back, monitoring the HV battery, and the 12 V also.
On the way there in the morning, my 12V system showed 14.8V all the way. HVAC fan on auto and not really blowing much at all.
On the way back it varied between 14.3-14.5V.

Is that all as expected and what others are seeing?

 

[Davexxxx]

An hr. after returning from a 16mi RT, 12.51V.

Plugged it back in and we'll see what it looks like tomorrow.

As for Ford Pass, I'll look for my sign in stuff, log out, re-sign in. See if that works.

 

[Davexxxx]

I connected a OBD2 adapter today and drove to work and back, monitoring the HV battery, and the 12 V also.
On the way there in the morning, my 12V system showed 14.8V all the way. HVAC fan on auto and not really blowing much at all.
On the way back it varied between 14.3-14.5V.

Is that all as expected and what others are seeing?

I don't know if that is normal or not but it is ample voltage.

 

[Davexxxx]

It was still flashing red when I unhooked it this morn. An hr. later, V= 12.59.

An hour after I came home from ~ 55 mi round trip, it is 12.63.

Plugged it back in and still flashing red, so it must measure something other than V to determine SOC.

 

[Ricksc]

Yes it does it measures how much the battery is charged. That’s why voltage doesn’t work for SOC. AGM batteries are a beast in them selfs. Low discharge ruins these batteries. They will never charge to 100%. I charge mine for 2 days says 100%. Light is green. Take if charger let truck go to sleep then check its at 80% next morning 75%. Battery is 3 months old. Fords charging system sucks.

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