Concerned that volts never get above 12.2 when it should be, I think 12.6 or better resting with engine off. I did these tests. No non start issues just wondering about the low voltage on a NEW 2019 6 month old Ranger that I really like. These are my test results this morning after charging it up yesterday @ 2 volt charger from 12.2 2 hours later to 12.9 reading on digital meter. Leaving it undisturbed over night for the BMS (battery management System) to take notice of the charge. Then upon testing this AM without engine running it was back to 12.2 Volts. Engine running 14.7 Volts. Engine running with all accessories on Brights/ AC/heated seats/fan high/ = 14.7 Volts.

KEY ON - Engine off with Bright headlights on for 5+ minutes. 12 Volts exactly.

Why it dropped from 12.9 to 12.2 over night? I dunno.... I think it should have been the same.

Your thoughts

 

Well just to clarify things a second. Charging a battery takes about 2 volts over and above the resting voltage. In a standard lead-acid battery the resting OCV is 12.65 volts at 77 deg. F., blah blah blah. Sometimes, folks will charge a weak or dead battery to 12 volts or so, and then think their work is done. So a battery needs to chug along for a while with the charger at 14.6 volts or so, several hours won't hurt anything, moderate outgassing is OK.

I don't think 12.9 volts charging is what you meant. But it pays to be clear.

I agree it shouldn't be drawing a battery down that quick.

 

This is a good number, and by checking after 10+ minutes or so, battery should "bounce back" to 100%.

There sure are a lot of parasitic drains on newer cars and trucks.

 

Those are the normal battery ranges that I see in my vehicles

just checked two that have tracking devices in them - neither have been driven for the past few days - one is at 12.2v and one is at 12.0v

no issues

 

12.0 volts is almost dead, roughly a 25% charge they don't last long that way.

 

There's a lot going on with newer vehicles, and it can get pretty complex, so I always suggest doing the simple checks first. To me, the easiest thing to check is the health of your battery.

This is the simplest first test: Disconnect the battery from the vehicle, charge it fully with an external smart charger, measure the voltage at the end of charging. Disconnect the charger, and measure the voltage after 1 hour and again after 8-12 hours. If resting voltage on a full charged and completely disconnected battery is anything less than about 12.75, that's bad.

Getting a parts store to test the battery is a good idea too. They can do a load test that most of us home mechanics don't have the equipment for.

It's pretty unlikely that your brand new vehicle has a bad alternator, malfunctioning battery management system, or an unusual parasitic draw, but if the battery checks out, those are the next things to check.

 

This is very important too. If you have a battery tender/maintainer handy, you really should connect it any time the vehicle sits for more than a few days, and overnight every few weeks anyway. Lots of people don't realize how low their battery is getting, and just assume as long as the vehicle starts when they turn the key, everything is fine.

 

Welcome to the Ford intelligent BMS system. The parameters are based on engine load, catalyst temp and vehicle speed to name a few. What you are seeing looks normal. Also remember the AGM battery needs to be charged properly and a full AGM is 12.85 volts not 12.65 like a flooded battery. You can also disable auto start stop and BMS with forscan and it will keep a stable voltage like traditional charging systems.

 

I did charge it with a 2 volt charger and I keep the SS permanantly off with a led night light in the pass 12V plug. Tested both in and out and it made no difference is such a low milliwatt draw. But I would like to turn off all the lights and dash startup every time I open the door?

 

What I found, is a tender's float charge (Usually 13.10 or thereabouts, depending on manufacturer) isn't enough to compensate for a high (though not too high) parasitic load. Green LEDs can be deceptive.

It is definitely better than nothing, though not by a whole lot. The battery will still get drawn down. Eventually it would kick on if the voltage reached a certain level I suppose but this parasitic load is less than ideal. The battery folks must love it though. The micro-amp chargers don't charge a deeply discharged battery effectively either, and that's what a parasitic or "phantom" load does, it really nukes 'em over time. They are basically only suitable for maintaining a full charged battery, exactly the situation we don't have here.

 

Disabling SS that way has no impact on the BMS. It has to be disabled in forscan. I assume you mean 2 amp charger? Does that charger have a AGM setting? If you want to disable the lights that can also be done with forscan, just enable dark mode.

 

Yeah I wouldn't use a "tender" type to charge a deeply discharged battery, I have higher amperage units for that. I'm a bit of a battery charger nerd though, I have five of em.

 

Well what I meant by that, a 50 milliamp draw, maybe a little more, is considered acceptable or within spec.

But it sure seems like a lot of late model cars and trucks exceed this, and it's anyone's guess as to why. Hearing this quite a bit with different makes and models. Maybe the GEM is reporting our shopping habits to the Goggle mothership or something, I dunno. But it really nukes the battery and reduces their service life considerably. The small tenders will go through their routine and green light but wait a few days, check the OCV. It will be down.

My Ranger shows a healthy draw just after shutdown and within maybe 15 minutes settles down to 30 mA, I checked it for several hours and overnight. But it will still suck a battery down pretty good after a day, to maybe 12.5, a tenth of a volt or so doesn't sound like much but this is excessive imo. With the battery disconnected it "holds" voltage for a long time, passes load test, conductance test, etc.

 

I can disable the BMS and SS with disconnecting a plug at the negative terminal on the battery. I get a higher resting voltage 12.6 versus 12.1, much better charge and with alternator running with lights on 13.9 disconnected and 14.6 connected? Very confusing.

 

Finally went in to the dealer to pick up my (bought with Ford points) NOCO battery starter JIC I need to use it - and had the dealer check my battery. They maintain as long as it is 12 volts it is normal. LOTS of complaints coming in from vehicles that had sat for a week with problem startingdue to electrical parasitic drain - BUT I finally had him put it on the machine for a load test and it came back "Good" with 12.5 so I am done for now and will just deal with it and disconnect the plug that keeps the SS system off and the alternator working old school style charging the battery as normal, NOT keeping it in a depressed voltage state.