Maximizing Battery Life

[IdahoRanger]

The top numbers seem accurate, but the bottom reading "does not compute," at 12.05 volts you should be ~ 50% charge, assuming it's an AGM battery. And yes with your battery still connected , despite things being turned off there is likely some parasitic discharge, IIRC some of the memory used in some devices draws a small amount of current as may some other components.
did you run the test several times ?

I understand these vehicles have some parasitic draw, but down to zero charge doesn't seem right.


Yes, tested more than once and charge showed 0% a couple times. Something is draining the battery over just two nights.

Finished a charge with the NOCO and looks good but still don't understand how it goes to zero in a couple nights.

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[RangerBill]

The top numbers seem accurate, but the bottom reading "does not compute," at 12.05 volts you should be ~ 50% charge, assuming it's an AGM battery. And yes with your battery still connected , despite things being turned off there is likely some parasitic discharge, IIRC some of the memory (volatile)) used in some devices draws a small amount of current as may some other components.
did you run the test several times ?

According to a state of charge chart I have, 50% charge on an AGM battery at 80 degrees should be 12.40 volts. This same chart shows 12.00 volts as 25% charge, so the Topdon SOC reading seems to be very low for 12.01 volts.

 

[TJC]

The top numbers seem accurate, but the bottom reading "does not compute," at 12.05 volts you should be ~ 50% charge, assuming it's an AGM battery. And yes with your battery still connected , despite things being turned off there is likely some parasitic discharge, IIRC some of the memory used in some devices draws a small amount of current as may some other components.
did you run the test several times ?

You're on the money... closer to 45% charge for AGM, but close enough. I've seen some charts go as low as 30% for a 12.05v charge of 12v battery. These readings also vary with temperature. The colder the lower the readings.

There is quite a bit of dark current with newer autos. You can minimize dark current, but only by disabling a lot of the modern electronic gadgets, bells and whistles. Most won't accept the tradeoff.

I have my 2020 Ranger behaving just like my 2005 Ranger with regards to dark current loss and battery target charge levels. But it required turning off electronics, etc, and reverting to the 4G Ranger's BMS charging patterns.

 

[dtech]

You're on the money... closer to 45% charge for AGM, but close enough. I've seen some charts go as low as 30% for a 12.05v charge of 12v battery. These readings also vary with temperature. The colder the lower the readings.

There is quite a bit of dark current with newer autos. You can minimize dark current, but only by disabling a lot of the modern electronic gadgets, bells and whistles. Most won't accept the tradeoff.

I have my 2020 Ranger behaving just like my 2005 Ranger with regards to dark current loss and battery target charge levels. But it required turning off electronics, etc, and reverting to the 4G Ranger's BMS charging patterns.

If I'm interpreting some of the readings correctly- cca for one the battery would seem to be good, wonder if the tester is doesn't give accurate

I understand these vehicles have some parasitic draw, but down to zero charge doesn't seem right.


Yes, tested more than once and charge showed 0% a couple times. Something is draining the battery over just two nights.

Finished a charge with the NOCO and looks good but still don't understand how it goes to zero in a couple nights.

I'd- if it's very cold I don't think your tester compensates and the battery voltage will be lower than at 80 degrees after the battery sits for a day or so and I doubt that Mr Topdon compensates for this thus the readings are less than accurate. A remote possibility is a bad cell within the battery. A clamp tester can tell you the current draw and verify you have parasitic loses but even when you think everthing is turned off there is still some current draw.

 

[IdahoRanger]

Thanks for the replies, measurement taken at about 50 degrees but it boggles the mind that a battery can discharge so quickly. Guess I could have kept my old one as it acted similarly.

 

[dtech]

Thanks for the replies, measurement taken at about 50 degrees but it boggles the mind that a battery can discharge so quickly. Guess I could have kept my old one as it acted similarly.

I can tell you that even though I've turned off as much as possible - updates, location info, Ford Pass, there is still current draw. My point of comparison is the new Weize battery I installed a few months back and the OEM Ford battery sitting in my garage - the OEM battery although 5 yrs old holds a charge close to 100% over a month, whilst the Weize now under the hood drops voltage after a day or two, a sure sign of parasitic current draw. Another bonus of ordering the Weize - no core charge, no return of old battery.

 

[got3fords]

Thanks for the replies, measurement taken at about 50 degrees but it boggles the mind that a battery can discharge so quickly. Guess I could have kept my old one as it acted similarly.

But would the truck start?

 

[TJC]

I can tell you that even though I've turned off as much as possible - updates, location info, Ford Pass, there is still current draw. My point of comparison is the new Weize battery I installed a few months back and the OEM Ford battery sitting in my garage - the OEM battery although 5 yrs old holds a charge close to 100% over a month, whilst the Weize now under the hood drops voltage after a day or two, a sure sign of parasitic current draw. Another bonus of ordering the Weize - no core charge, no return of old battery.

Turn off Telematics in Forscan, pull the Telematics fuse (IIRC 9 inside the cabin), and unplug the cellular modem in the passenger kick panel. I also turned off chimes, light duration to minimum, and a few other items. and If you haven't unplug the BMS sensor at the battery or set SOC to 95% - 100%.

Then see how long it takes to discharge. Mine now matches my 2005 Ranger. I charged both up and let them sit for a week. Same discharge rate.

 

[IdahoRanger]

But would the truck start?

Didn't try.?

 

[got3fords]

Didn't try.?

Ahhhh, you're killing me!

 

[TJC]

I found this statement in a Ford GSB on Batteries:

​

"Battery SOC drops about 10% a month in Transport Mode and more than 20% in Customer Mode"​

​

I find it interesting that Ford could quantify the Transport Mode drop, but chose "more than 20%" in Customer mode.

Ford targets a SOC of 70% (12.36v) for XL and XLT models, and 75% (12.4v) for Lariat models. That means your brand new battery never sees a full charge using the Ford BMS defaults and starts sulfating immediately, and the process speeds up as the dark current drains your battery to 12v by morning. This is the voltage that I was seeing after my truck sat overnight. Fully charging your battery with a charger doesn't help. As soon as you start your truck Ford BMS drains the battery down to target SOC of 70% or 75%.

Sulfation begins at <=12.4v. It’s also important to note that the battery is best at temperatures of 75F degrees. The rate of self-discharge doubles for every 10 degrees above 75F.

And now you know why people are replacing their batteries between 18 months and 3 years.

 

[TJC]

Here is the Ford bulletin that I pulled the information from. Interesting read.

 

[pboggini]

Ford targets a SOC of 70% (12.36v) for XL and XLT models, and 75% (12.4v) for Lariat models. That means your brand new battery never sees a full charge using the Ford BMS defaults and starts sulfating immediately, and the process speeds up as the dark current drains your battery to 12v by morning. This is the voltage that I was seeing after my truck sat overnight. Fully charging your battery with a charger doesn't help. As soon as you start your truck Ford BMS drains the battery down to target SOC of 70% or 75%.

Interesting. My 2019 STX (XL) was set to 75%. With the new Lariat battery and desulfator it's now set to 100%. I had it at 95% and saw the wild voltage swings down in the 12's. Those persisted a bit after I set it to 100% but now I don't see less than 13.7 or so possibly because it's quickly gotten colder here. Auto Stop/Start is as regular as clockwork now except for the times I press the button.

peterb

 

[TJC]

Interesting. My 2019 STX (XL) was set to 75%. With the new Lariat battery and desulfator it's now set to 100%. I had it at 95% and saw the wild voltage swings down in the 12's. Those persisted a bit after I set it to 100% but now I don't see less than 13.7 or so possibly because it's quickly gotten colder here. Auto Stop/Start is as regular as clockwork now except for the times I press the button.

peterb

I never tried setting the SOC to 100% with ASS active. You should be fine as long as you don't see major voltage spikes (> 14.4v) when coasting or braking. If you are seeing charge voltages higher you will be overcharging the battery. Seeing 13.7v - 14.4v range is what you are looking for.

 

[pboggini]

I never tried setting the SOC to 100% with ASS active. You should be fine as long as you don't see major voltage spikes (> 14.4v) when coasting or braking. If you are seeing charge voltages higher you will be overcharging the battery. Seeing 13.7v - 14.4v range is what you are looking for.

I used to see those higher voltages with the old battery and my SOC set to 95% mostly in the cold mornings (40-50 degrees) or colder. When I first put in the new battery and saw the voltage swings I'd sometimes see the voltage briefly go to 14.5 but since setting it to 100% is seems to have calmed things down a bit. It's only been a couple of weeks.

BTW, I tried to reset the battery in both Forscan and using method in the manual but Forscan keeps telling me the battery is almost 1500 days old. Anyone else seen that?

peterb

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