Charging Sys-Question for Phil / Ford Techs / Anybody

[dtech]

Sounding like a "what oil do you recommend" thread now. Is @AzScorpion getting commission on ctek chargers?
At the risk of going in another direction, after reading about the function of the bms, I'm curious what disconnecting the bms does. My thought is you are running an unregulated charge to the battery which will end up shortening the battery life. Or is there a failsafe that limits the max charging voltage?
@airline tech, wondering if that scenario has been tested.

this is a fallacy - the unregulated out of control alternator scenario, like an out of control nuclear chain reaction. Disconnect the bms and things revert to a charging system used for decades, the alternator still contains a built in rectifier and voltage regulator(maybe done by the ecu). I've had the bms disconnected for over a year and battery works fine. There are certain situations like very hot climates I'd advise against this as a precaution, but otherwise it works, the bms is not voodoo or black magic, just a modification of voltage regulation/charging tied primarily to support the ass function. As you can see by my avatar I live life on the edge but when I initially disconnected the bms I dressed for any possible outcome, but in the end the only one I've experienced is a healthy battery. If you or others wish to contract me to perform a bms disconnect it can be done for $2k plus expenses. Or rate can be reduced if it's done as a group of 5 or more with close geographic proximity, schedule is filling up quickly though as I also perform damper removal services.

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[Trustable]

Sounding like a "what oil do you recommend" thread now. Is @AzScorpion getting commission on ctek chargers?
At the risk of going in another direction, after reading about the function of the bms, I'm curious what disconnecting the bms does. My thought is you are running an unregulated charge to the battery which will end up shortening the battery life. Or is there a failsafe that limits the max charging voltage?
@airline tech, wondering if that scenario has been tested.

Thanks I’ll take a look!

 

[dtech]

FWIW, I have a 21 Lariat that I have put just shy of 22k miles on since I got it in August 21. My first mod was a Auto Start/Stop Eliminator and have not used ASS since. The truck seldom sits for more than a day and the most it has sat is 5 days. I have not had any issues with the battery.

With that said, I have a gauge pod on the dash with a volt meter. This and the other battery threads have me paying more attention to what is happening.

Every time I start the truck the charge voltage always goes to 14.5 to 15 volts. The length of time it stays in that range varies but it typically stays there longer when it is cold outside (freezing) but it always stays there for at least 4 or 5 miles. Eventually the voltage will drop down into the 13 to 13.5 range, it has dropped below 13 volts but that is very infrequent. The interesting characteristic is when I take my foot off the gas, coasting or idling, the voltage always jumps back up into the 14.5 to 15 range and will immediately drop back down to 13 to 13.5 when back on the gas. After a drive when the truck is shut off the battery voltage is typically 12.7 to 12.8 volts and has dropped to 12.1 after sitting over night.

normal as far the relationship of voltage to startup and rpms, and that 12.8v normal, the overnight voltage drop may be a sign the battery's days are numbered, but batteries don't always behave as expected, another gent posted his battery tested bad yet had acceptable internal resistance and held a charge at ~ 12.5 volts .

this is why an instant load test as done at an auto parts store isn't always accurate, posts indicate when going to a Ford dealer it takes 4 to 5 hrs to test the battery as they 1st charge it to 100%, then let it rest for several hrs and then conduct testing, in some cases leaves owners owners that were getting messages regards battery state confused if it tests good, but that goes back to what the bms is doing with respect to charge levels. Doesn't make a whole lot of sense.

 

[IdahoRanger]

I think the jury is still out on #1 but it does seem like the BMS only charging to 75% is the culprit.

I have a Lariat and had my battery die at 18 months. Dealer said it had 2 dead cells and replaced it under warranty. Since then I always hook it up to a maintainer at least 2-3 days a week. I use a LED nightlight that disables A/S/S. So far so good and everything's been working/charging the way it should. ?

Dave, doesn't your Livernois tune disable ass? Mine does.

 

[got3fords]

I used the Noco charger and plug installed in the air dam to make it easy to plug in. It is permanently connected so no clamps. Charger link. https://www.amazon.com/dp/B07W3QSMF9?ref=ppx_pop_mob_ap_share

I wonder what options there are for people with no garage and have to park far away from an AC outlet.

 

[KJRR]

I wonder what options there are for people with no garage and have to park far away from an AC outlet.

There are solar chargers that can be used. Trouble is you can't plug into cigar lighter plug because that turns off, can't leave it outside when it snows or rains. That leaves wiring it in the harness or fuse panel somewhere.
I'll probably wait until I go through another battery before I decide to try a solar charger.

 

[got3fords]

this is a fallacy - the unregulated out of control alternator scenario, like an out of control nuclear chain reaction. Disconnect the bms and things revert to a charging system used for decades, the alternator still contains a built in rectifier and voltage regulator. I've had the bms disconnected for over a year and battery works fine. There are certain situations like very hot climates I'd advise against this as a precaution, but otherwise it works, the bms is not voodoo or black magic, just a modification of voltage regulation/charging tied primarily to support the ass function. As you can see by my avatar I live life on the edge but when I initially disconnected the bms I dressed for any possible outcome, but in the end the only one I've experienced is a healthy battery. If you or others wish to contract me to perform a bms disconnect it can be done for $2k plus expenses. Or rate can be reduced if it's done as a group of 5 or more with close geographic proximity, schedule is filling up quickly though as I also perform damper removal services.

There are solar chargers that can be used. Trouble is you can't plug into cigar lighter plug because that turns off, can't leave it outside when it snows or rains. That leaves wiring it in the harness or fuse panel somewhere.
I'll probably wait until I go through another battery before I decide to try a solar charger.

If I did solar, I would probably do something like connect semi-permanently under the hood with an easy to access connector and just pull the charger out of the back seat and set it on the hood or ground. Assuming they would be weather proof.

 

[AzScorpion]

Dave, doesn't your Livernois tune disable ass? Mine does.

When Anthony sent my tune he sent one that didn't have it disabled. He did say he could resend another one disabling it but I had to use my friends PC (I have a Mac) and it's more of a pain seeing as he's 15 miles away. But I'm getting a cheap PC soon so I'll probably send it back to have them disable it and get the revised soft shift tune.

 

[Tcarter]

Does sound like your battery is on the way out, if you do not use ass I'd recommend you consider disconnecting the bms sensor at the neg cable (reconnect before trip to dealer) , continue to use trickle charger and see if this helps. A sign of a dying battery is inability to hold a charge, but with the bms disabled the alternator should get the battery to a bit higher state of charge than the trickle charger, some chargers have a restore setting which might help out, might be worth calling ford customer service to see if they can get appointment moved up, I'd embellish the situation and make it more urgent, maybe use roadside assistance if you must. Good luck.

Thanks! Will consider this.

 

[dtech]

Thanks! Will consider this.

Fair amount of misconceptions and/or generalizations regards AGM batteries and the role of the BMS. AGM are wet cell lead acid but not flooded . They can be charged to a degree like a flooded batt - 15v + , but as the soc increases so does the internal resistance , to a greater degree than flooded so an agm smart charger will reduce the voltage as the soc ramps towards 100% - this lessens the heat produced by internal resistance. So Ford sets the soc to 70% or 75% for ass usage, this allows for putting up to 15v + to rapidly recharge the battery to 70% or 75% , AGM batteries do well handling this cycling but like any lead acid battery consistent state of undercharge degrades the battery. This limited SOC also promotes fuel efficiency owing to the extension of charge times as battery SOC ramps towards 100% but the BMS negates that.
Disconnecting the BMS and the charging system reverts to one used in a flooded lead acid and it will charge the batt to 100% - and at times 15V+ , the risk is not of the battery exploding but it can raise the battery temp, if the internal battery temp exceeds a safe limit - sealed AGM have a pressure relief valve - this outgasses vapors, mostly water but unlike unsealed flooded lead acid batts you cannot replace that H2O .
In my case I live where temps rarely exceed 90F , my vehicle is in a warm garage so I don't use power hungry stuff like electric defrosters, heated seats, thus the battery is generally kept at a higher SOC and I occasional trickle charge. So I believe the overheating risk to be slight.
Wanted to pass this along as an FYI .

 

[airline tech]

FWIW, I have a 21 Lariat that I have put just shy of 22k miles on since I got it in August 21. My first mod was a Auto Start/Stop Eliminator and have not used ASS since. The truck seldom sits for more than a day and the most it has sat is 5 days. I have not had any issues with the battery.

With that said, I have a gauge pod on the dash with a volt meter. This and the other battery threads have me paying more attention to what is happening.

Every time I start the truck the charge voltage always goes to 14.5 to 15 volts. The length of time it stays in that range varies but it typically stays there longer when it is cold outside (freezing) but it always stays there for at least 4 or 5 miles. Eventually the voltage will drop down into the 13 to 13.5 range, it has dropped below 13 volts but that is very infrequent. The interesting characteristic is when I take my foot off the gas, coasting or idling, the voltage always jumps back up into the 14.5 to 15 range and will immediately drop back down to 13 to 13.5 when back on the gas. After a drive when the truck is shut off the battery voltage is typically 12.7 to 12.8 volts and has dropped to 12.1 after sitting over night.

Finally, I have another owner, watching what it does, thanks.

Plus: Just an FYI, Temp does play a role in charging the battery, I have noted a higher charging voltage if temp is around 32 deg, so higher charge when cold (In the 14's) and lower charge when warm (13's) (When Driving at Night) battery under load

Well, I have an answer to my question as of this AM, I had to make a trip to Home Depot and with it set to factory SOC 75%, this closely models your description

From post #1 - here is the reason for 75% SOC - It's answer #3

3. The charging system charges to 75% and maintains 75% and then using Smart Reg Charging, during de-acceleration, the generator produces an extra boost charge into the battery thus raising the SOC to 100% which I don't think the Ranger has this feature, like other Ford models and this is the reason for only charging to 75%, leaving 25% buffer for the boost.

So, I have confirmed with my truck and the above.

Here are my truck observations:

Driving in Day: (OAT 34 Deg)

At wake up 11.9 Volts
Drive: 12.7 / 12.8 (During Accel)

Deacceleration: Voltage Jumps up and varies: 13.4 -15.0 Volts, it is a quick jump, and it is very noticeable is foot off gas pedal and coasting down a long hill, it will stay in boost until you come to a stop, from what I have noticed

So, the above is Smart Regentive Charging: The Generator is Decoupling, and using that energy to boost battery SOC to 100%

Stoplight (Idle) - As Low as 12.2 Volts (varies) Between 12.2 and 12.5

Engine Shutdown: Have 12.8 V @ shutdown and then after interior / exterior lights time out - 12.6 v

Ref: The initial voltage jump @ start-up, this is due to:
The Generator is turned off, during cranking, after engine is running, the system is taking the reading it received from the (Sleep Mode) recalibration and setting the target charge voltage based on that reading.
But, before it sets the target voltage, it produces a small boost charge back into the battery after the heavy load it just received (starter cranking)

So, for mine, when I bumped my Target SOC to 80%, I pretty much had the same end result. 12.8 Volts at shutdown, and would hold after lights timed out, but however at the Wake-Up voltage would still be 11.9/12.0 volts. (By Wake Up: Meaning I am putting into ASSY, before I start the truck to view the volt gauge)

So, this is the sole reason for setting the Battery Target SOC to 75%, to allow for a buffer zone to be able to handle the boost charge

So, to settle the disconnect the BMS sensor, I plan on disconnecting mine and monitor what the charging system actually does, I have not seen anyone post this info, only speculation that it reverts to old school charging, this system is controlled by a BCM and PCM, at this point the only thing I know for sure, If there is a fault with the charging system (Generator) it will revert to a fail-safe charge of 13.8 volts, now what I don't know is if disconnecting the BMS sensor will trigger the same result. All that has to be done is Test it out and monitor for the results.

 

[dtech]

Finally, I have another owner, watching what it does, thanks.

Plus: Just an FYI, Temp does play a role in charging the battery, I have noted a higher charging voltage if temp is around 32 deg, so higher charge when cold (In the 14's) and lower charge when warm (13's) (When Driving at Night) battery under load

Well, I have an answer to my question as of this AM, I had to make a trip to Home Depot and with it set to factory SOC 75%, this closely models your description

From post #1 - here is the reason for 75% SOC - It's answer #3

3. The charging system charges to 75% and maintains 75% and then using Smart Reg Charging, during de-acceleration, the generator produces an extra boost charge into the battery thus raising the SOC to 100% which I don't think the Ranger has this feature, like other Ford models and this is the reason for only charging to 75%, leaving 25% buffer for the boost.

So, I have confirmed with my truck and the above.

Here are my truck observations:

Driving in Day: (OAT 34 Deg)

At wake up 11.9 Volts
Drive: 12.7 / 12.8 (During Accel)

Deacceleration: Voltage Jumps up and varies: 13.4 -15.0 Volts, it is a quick jump, and it is very noticeable is foot off gas pedal and coasting down a long hill, it will stay in boost until you come to a stop, from what I have noticed

So, the above is Smart Regentive Charging: The Generator is Decoupling, and using that energy to boost battery SOC to 100%

Stoplight (Idle) - As Low as 12.2 Volts (varies) Between 12.2 and 12.5

Engine Shutdown: Have 12.8 V @ shutdown and then after interior / exterior lights time out - 12.6 v

Ref: The initial voltage jump @ start-up, this is due to:
The Generator is turned off, during cranking, after engine is running, the system is taking the reading it received from the (Sleep Mode) recalibration and setting the target charge voltage based on that reading.
But, before it sets the target voltage, it produces a small boost charge back into the battery after the heavy load it just received (starter cranking)

So, for mine, when I bumped my Target SOC to 80%, I pretty much had the same end result. 12.8 Volts at shutdown, and would hold after lights timed out, but however at the Wake-Up voltage would still be 11.9/12.0 volts. (By Wake Up: Meaning I am putting into ASSY, before I start the truck to view the volt gauge)

So, this is the sole reason for setting the Battery Target SOC to 75%, to allow for a buffer zone to be able to handle the boost charge

So, to settle the disconnect the BMS sensor, I plan on disconnecting mine and monitor what the charging system actually does, I have not seen anyone post this info, only speculation that it reverts to old school charging, this system is controlled by a BCM and PCM, at this point the only thing I know for sure, If there is a fault with the charging system (Generator) it will revert to a fail-safe charge of 13.8 volts, now what I don't know is if disconnecting the BMS sensor will trigger the same result. All that has to be done is Test it out and monitor for the results.

Fyi - one of the better (accurate) articles on smart charge alternator systems - however it doesn't give much address to the particulars that ass presents.

https://garagewire.co.uk/news/compa...arge-alternators-everything-you-need-to-know/

 

[Dgc333]

So, to settle the disconnect the BMS sensor, I plan on disconnecting mine and monitor what the charging system actually does, I have not seen anyone post this info, only speculation that it reverts to old school charging, this system is controlled by a BCM and PCM, at this point the only thing I know for sure, If there is a fault with the charging system (Generator) it will revert to a fail-safe charge of 13.8 volts, now what I don't know is if disconnecting the BMS sensor will trigger the same result. All that has to be done is Test it out and monitor for the results.

I disconnected my BMS sensor yesterday to see what happened. It stayed at a constant 14.4 volts, never varied.

 

[dtech]

Dearest Airline Tech - generators in cars became a thing of the past , distant past as in the 60s, you are showing your aviation background.

.

 

[Tim H.]

And I have a Lariat with no changes to the BMS and I've not used a maintainer at all and I'm coming up on 4 years with the original battery - and no signs it is getting close to giving up. So I'm guessing there is more than one issue in play here.

I have a 2020 Lariat W/23k miles (built 3/2020) and no battery issues.

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