Ugh_J
Active Member
One thing you can do that will test the battery: put it on a trickle charger overnight. Get a good one that will keep throwing 1.5A intermittently even if it shows full, like a BatteryMINDer: https://www.amazon.com/gp/product/B00Q3CM2QY/ If you put it on there overnight or better yet over a weekend, one of two things is going to happen: 1) It eventually goes into maintenance mode indicating it actually got to full charge and is trickle charging/desulfating ending up around 12.9V after disconnecting and waiting an hour, or 2) it will never show maintenance mode, which (from my experience) indicates the battery will not take or hold a full charge. There are more scientific ways to test for certain battery faults but this works, is cheap, and doesn't involve someone else trying to sell you something.
There is another item that might help you keep an eye on the battery: BM2 Bluetooth car battery tester https://www.amazon.com/gp/product/B01MT4583U is the one I have. It's not per se a battery tester but it will show you two things: the voltage, in a graph, over the last 1-15 days, and it will also tell you what the voltage dipped to on crank. On my bad battery, not only was it doing the <12.5V thing overnight AND the odd load-shed things AND not holding voltage even after trickle charging, it was also dipping down to like 9.3V on crank in 70F weather. My new battery sits at ~12.85-12.93V after driving it with the headlights on for a couple hours, and it also stays above 10V on cranking. Over memorial day weekend, I drove down at night (3.5hrs) and battery SoC was at 100% when I arrived. We put it in the barn at ~12.95V Thursday night about 10:45PM and when I went out to crank it Monday afternoon about 2pm, it was down to 12.82V.
That said, if you're like me and only drive it 10-20 minutes around your local town (even daily) it will have a tough time keeping it topped up as-built. Two things I did to help with that: Added an auto-start/stop eliminator (the one that goes in-line with the OBD2 port wiring), and changed the Battery Target State Of Charge from 80% to 95% via Forscan. Mine now usually sits at about 90% SoC (instead of ~60-70%) and ~12.75V resting. Driving during the day, it will kick the amps up to 10-15 after replenishing from the crank drain if it's under 90% and when it gets up to ~93% or so will start draining the battery (negative amps on the battery current PID) intermittently. At night (or if I just manually turn on the headlights) it sits at ~14.3V and 5A+ until it hits 93%, then it slowly tails off until 95%, then it drops down to ~13.5V and ~0-1.5A which is interestingly the same thing the good trickle chargers do.
I learned quite a bit monitoring voltages and behaviors the ~10 days before I replaced the original battery and comparing those results with what I'm seeing with the new battery and settings. The Ford documentation that's floating around has some good info but they don't (for perhaps obvious reasons) provide things like charge curves and charge/discharge logic vis-a-vis Target SoC. Get something like an OBDLink MX+ and set up a good dashboard with Battery voltage/current, state of charge, charge mode, and days in service, and keep an eye on it. Try a few things. Don't be terrified to do some reasonable experimentation and learn how your vehicle works with your use cases; these things aren't nukyular power plants for cryin' out loud.
There is another item that might help you keep an eye on the battery: BM2 Bluetooth car battery tester https://www.amazon.com/gp/product/B01MT4583U is the one I have. It's not per se a battery tester but it will show you two things: the voltage, in a graph, over the last 1-15 days, and it will also tell you what the voltage dipped to on crank. On my bad battery, not only was it doing the <12.5V thing overnight AND the odd load-shed things AND not holding voltage even after trickle charging, it was also dipping down to like 9.3V on crank in 70F weather. My new battery sits at ~12.85-12.93V after driving it with the headlights on for a couple hours, and it also stays above 10V on cranking. Over memorial day weekend, I drove down at night (3.5hrs) and battery SoC was at 100% when I arrived. We put it in the barn at ~12.95V Thursday night about 10:45PM and when I went out to crank it Monday afternoon about 2pm, it was down to 12.82V.
That said, if you're like me and only drive it 10-20 minutes around your local town (even daily) it will have a tough time keeping it topped up as-built. Two things I did to help with that: Added an auto-start/stop eliminator (the one that goes in-line with the OBD2 port wiring), and changed the Battery Target State Of Charge from 80% to 95% via Forscan. Mine now usually sits at about 90% SoC (instead of ~60-70%) and ~12.75V resting. Driving during the day, it will kick the amps up to 10-15 after replenishing from the crank drain if it's under 90% and when it gets up to ~93% or so will start draining the battery (negative amps on the battery current PID) intermittently. At night (or if I just manually turn on the headlights) it sits at ~14.3V and 5A+ until it hits 93%, then it slowly tails off until 95%, then it drops down to ~13.5V and ~0-1.5A which is interestingly the same thing the good trickle chargers do.
I learned quite a bit monitoring voltages and behaviors the ~10 days before I replaced the original battery and comparing those results with what I'm seeing with the new battery and settings. The Ford documentation that's floating around has some good info but they don't (for perhaps obvious reasons) provide things like charge curves and charge/discharge logic vis-a-vis Target SoC. Get something like an OBDLink MX+ and set up a good dashboard with Battery voltage/current, state of charge, charge mode, and days in service, and keep an eye on it. Try a few things. Don't be terrified to do some reasonable experimentation and learn how your vehicle works with your use cases; these things aren't nukyular power plants for cryin' out loud.
