Maximizing Battery Life

[airline tech]

Here is a great video that explains the charging duty cycle, however, is does not specifically mention Regenerative Charging, but is does show the higher duty cycle will produce a higher charging voltage of 15.1

Understanding and Diagnosing Ford Smart Charging System - YouTube

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[TJC]

Had errands to run, lots of stop n go, 5 or 6 stores over 3 hours, temps in the low to mid 80'sF. The entire time charge voltage never exceeded 13.8v. A low of 13.5, and generally 13.7v-13.8v. Perfect float voltages.

I did notice a mild transmission jolt once or twice when stopping. Didn't do it all winter so I think it may be heat related. Oil change due in 500 miles at about 18K miles. I think I will add the trannie dipstick and the PPE deep transmission pan before changing the engine oil. Gonna be a long day. Time to start looking at dipstick mounting locations under the hood.

 

[got3fords]

This morning's drive was about 63F. The charge voltage was a constant 13.9ish, no regen charging. The drive home was mid 80's, cruise voltage about 13.7, regen 14.3ish. Really confusing how and why and how much it charges.

 

[TJC]

You're running with the sensor connected right? And at stock SOC?

 

[airline tech]

This morning's drive was about 63F. The charge voltage was a constant 13.9ish, no regen charging. The drive home was mid 80's, cruise voltage about 13.7, regen 14.3ish. Really confusing how and why and how much it charges.

Just curious if both drives - Headlights were on - If so, then that would be normal.
If either was a daylight drive and no headlights, then the base battery voltage was below the SOC you have set.
I only see charging voltage like those, if it is cold or lights are on, but I just remembered that all of my testing thus far was cooler temps, I did a quick meter check the other day and I see the 12.4-12.7 cruise voltage with the regen in the 14's

I can't remember if you changed the SOC from factory.

I like you do not plan as of yet, to disable or disconnect the BMS, I don't have ASS so that is not a factor.

From what I gather the Desulfer only works at/above 13.5 volts, from TJC's testing, so if I were to install it, it would only work (spring/summer) temps - if I turn on the headlights - Correct?

Of course, it would work the brief time after start-up and the charging system is recovering from (Night Sleep-Draw) and (Starting-Draw), mine recovers within 5 minutes or so and drops down from 13's to 12's on first start after sitting overnight. (With Daytime drive and no headlights and warm temps)

To answer your question awhile back, old school battery testers were carbon pile (load testers) place a load on the battery and see where the voltage drops goes,

The testers like Top Don are a Conductance Tester, the tester puts a small current through the battery and it measures internal resistance.
So far I have not played with mine much BT200, I just used it for a battery test, and watched charging voltage, as it matched my voltmeter plugged into the Power Point, I have not done any other testing with it

 

[airline tech]

You're running with the sensor connected right? And at stock SOC?

He's connected, not sure of his SOC setting.

 

[TJC]

He's connected, not sure of his SOC setting.

For the record, my last few runs where I reported being in the float zone (13.5v-13.8v) were in daylight with lights off.

The old school battery load testers are accurate, but IMO, draw down too much current too quickly and can permanently weaken the battery. On my load tester, the user has manual control over how long to let the battery discharge (you simply press and hold the button), and going too low is definitely risky. IIRC, my manual states not to exceed 10 seconds.

And it is a very good idea to put the battery on the charger immediately after the load test.

 

[TJC]

From what I gather the Desulfer only works at/above 13.5 volts, from TJC's testing, so if I were to install it, it would only work (spring/summer) temps - if I turn on the headlights - Correct?

The threshold is set at 13.5V from the factory, but I have read reports of people calling support, and being instructed on how to adjust the threshold. Support had the customer open the unit to do it. I suspect that there is a pot inside.

I never had the need to pursue the issue, so I did not investigate further.

You really do not want to be draining the battery when desulfating it. The process needs to be done in float maintenance voltage range. But you could set it to the SOC threshold or a little above.

To get it right, you'd probably want to use an adjustable DC power source allowing you to monitor and set the threshold on the bench... far more accurate. I am a staunch proponent of "Definable Repeatable Processes".

 

[got3fords]

He's connected, not sure of his SOC setting.

Not if sure he was talking about me, he didn't quote me. Stock SOC, and BMS, ASS enabled.

 

[got3fords]

The threshold is set at 13.5V from the factory, but I have read reports of people calling support, and being instructed on how to adjust the threshold. Support had the customer open the unit to do it. I suspect that there is a pot inside.

I monitored the voltage when I had the desulfator on the bench on my lawn mower battery. The turn-on threshold was more like 13.6- 13.7. Not too worried about it. I don't think it has to be active all the time to accomplish it's purpose.

 

[TJC]

Mine definitively cutoff at 13.5v

Maybe we are saying the same thing, just from opposite ends of the stick.

 

[got3fords]

Mine definitively cutoff at 13.5v

Maybe we are saying the same thing, just from opposite ends of the stick.

Very possible, there has to be some hysteresis.

 

[airline tech]

Well I’m stumped - thought I had the charging system down - and now it’s warmer out -I plugged in my meter and had a constant charge of 14.5 volts for a 20 mile drive - temp 70 degrees- daytime- no lights / no hvac
Shut down truck - battery voltage at 12.9
Restarted and voltage stayed 14.5
So this leads me to think - the pcm is addressing sulfation by forcing a higher charge - even though its not needed
So as 3fords reported - higher charge voltage than my cooler weather tests had -so more testing and research I guess - this system is hard to pinpoint exact operating parameters-Grr

 

[got3fords]

Well I’m stumped - thought I had the charging system down - and now it’s warmer out -I plugged in my meter and had a constant charge of 14.5 volts for a 20 mile drive - temp 70 degrees- daytime- no lights / no hvac
Shut down truck - battery voltage at 12.9
Restarted and voltage stayed 14.5
So this leads me to think - the pcm is addressing sulfation by forcing a higher charge - even though its not needed
So as 3fords reported - higher charge voltage than my cooler weather tests had -so more testing and research I guess - this system is hard to pinpoint exact operating parameters-Grr

Agree, the system is quite confusing. The charge voltage, regen voltage, when the ASS enables, etc all varies so much.

 

[dtech]

Well I’m stumped - thought I had the charging system down - and now it’s warmer out -I plugged in my meter and had a constant charge of 14.5 volts for a 20 mile drive - temp 70 degrees- daytime- no lights / no hvac
Shut down truck - battery voltage at 12.9
Restarted and voltage stayed 14.5
So this leads me to think - the pcm is addressing sulfation by forcing a higher charge - even though its not needed
So as 3fords reported - higher charge voltage than my cooler weather tests had -so more testing and research I guess - this system is hard to pinpoint exact operating parameters-Grr

I'm skeptical that it's desulfation, my understanding is that works on pulses of current to break the crytals, I suspect what you are seeing is the charging system going into saturation mode , high voltage at 14.5 but very low amperage because the battery is fully charged and the accessory draw is relatively low. With colder temps a bit more power is required to maintain the charge, so although volts maybe slightly lower amperage is higher, to understand if this correct you would need to monitor the current in the circuit or get your hands on documentation or next time you test by driving put on a bunch of power consuming accessories and see if the charging voltage drops. All of this possible with modern power regulation systems as they have the ability to modulate both voltage and amperage, charging at a higher voltage but very low amperage is not going to create excessive heat in a battery with high SOC.

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