Maximizing Battery Life

[pboggini]

Missed Option 4 and any variants!

In a few years we may have answers based on battery longevity.

I'm hoping we will know as I'm hoping that my battery lasts at least another year and/or doesn't look like it failed due to overcharging. As mentioned before, I'll come clean and tell you all if my battery dies an ugly over charged death.

So far I'm pretty happy with the results of 90% for about a month or so now.

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[dtech]

I think we are saying the same thing.

I see absolutely none of the regenerative behavior with the BMS unplugged. No low voltage at cruise or throttle, and no spikes to 15v+ when coasting or braking.

Whether the BMS is still active and imitating the conventional charge system, or it is electrically inactive, is immaterial, as the results with the BMS sensor disconnected are identical to those I see on my "BMS"less Ford. I see substantially higher battery SOC rates "at rest" without the BMS sensor than with it.

More importantly, the float voltages are achieved 100% of the time with the BMS sensor unplugged, and my desulfator is active when the engine is running - 100% of the time.

Ford has stated that the Ranger's battery will lose 20% in one month if not driven. I am assuming that Ford is referencing SOC when they made the statement. If the truck is at 100% or 12.85v at rest, in one months time the battery will be at 12.64v - just a tad under 75% SOC. But if you start at 75% or 12.65v SOC and pull the same .21v, in a months time your battery will be at 12.44v or roughly 59% SOC. This becomes even more troublesome for those who drive under 15 miles to work or let their truck sit for extended periods, as the BMS will never recover to the 75% SOC.


In my simple mind it comes down to this..

1. BMS Sensor connected = Discharge your battery while you drive to 75% (or less depending on driving distance). And the absolute most you can ever hope for is something less than a 75% SOC "at rest". Dark current over night will see to that.
   
   Or
   
   
2. BMS Sensor Connected / Disabled in Forscan = Charging system equivalent to "Alternator regulated" cars where the system charges the battery to 100% and then drops voltages to float charge rates of 13.6v-13.9v.
   
   Or
   
   
3. Or you could do as many do on the forum, purchase a nice high quality desulfating charger and plug your truck in regularly. But if you think about this logically, doing so simply transfers the CO2 savings Ford gained to the power plant supplying you with the energy which you are paying for, to keep the battery healthy.

Where does the Merry-Go-Round end? It's all a shell game, and I doubt that there is any C02 savings at all.

For me it's Option #2 - with an onboard desulfator

pretty much we are - with bms unplugged my belief is the functionality of the smart charge is there - including regen capability - key word being capability because if the battery is maintained at a high SOC there is little demand for the regen power to be utilized/generated, in theory we should see extended battery life owing to 2 factors :
- LA batts are happier when maintained at full SOC
- any battery has finite no of discharge/charge episodes, so not using the ass and the bms is going to significantly decrease those cycles
- a 3rd factor applies to your use of continual desulfation

Based upon in depth understanding of Ford's charging system I see 0 chance of batt overcharge by disco the bms.

When my OEM AGM gives it up it will be replaced by Wally Mart flooded lead acid - their batts cost less then most and I like that I can replenish H2O when needed.

I can see the BMS being effective for some - but the % of owners that do realize any mpg gains may be small.

And to your batteries - live long and prosper.

 

[airline tech]

Here is another article but again this leads to a question.

So if the Alternator Pulley is decoupled, how are you increasing the mechanical load on the engine for engine braking, unless the pulley somehow still ties into the mix.
I think that this may be another form of the system and it does not have the (OAD) pulley
Plus, they give you a picture of a brake, Regenerative Braking is different from Regenerative Charging, (Braking actually uses the Brakes - and spin-down to produce a charge voltage)


What is regenerative braking?

Regenerative braking is an energy recovery technology that takes the kinetic energy of the vehicle that is normally converted into wasted heat in the brake pads and discs during braking and instead converts it into electrical energy to re-charge the starter battery. This is made possible because of the use of smart alternators that can be controlled by the ECU when deceleration is detected. During deceleration (for example when taking your foot off the accelerator) the ECU boosts the alternator voltage output as high as 15V+ to create a burst of charge into the battery. This high voltage puts an increased mechanical load on the engine, resulting in increased engine braking, meaning less of the kinetic energy is converted to wasted heat in the pads and discs. So the deceleration of the vehicle is putting charge back into the battery, saving fuel that would otherwise be required to re-charge it.

This charge is then used to power the vehicle's electrical systems when the vehicle is accelerating or travelling at constant speed. During this time the alternator output voltage is reduced (to as low as around 12.5V), which reduces the load on the engine with a consequent reduction in emissions. Regenerative braking is only effective if the starter battery has some spare storage capacity to absorb the charge created by the alternator during deceleration. If the starter battery was fully charged the electrical energy created would be wasted and so the ECU aims to maintain the battery at around 80% state of charge (low enough to have spare storage capacity but high enough to guarantee engine starting if required).

 

[TJC]

I just got back from a 20 mile round trip wit a 30 minute interlude between the trips. 85F outside. Charging system quickly dropped to 14.1v and on the way back dropped to 14.0v. No regenerative anything going on, and now sub charging either.

 

[dtech]

Here is another article but again this leads to a question.

So if the Alternator Pulley is decoupled, how are you increasing the mechanical load on the engine for engine braking, unless the pulley somehow still ties into the mix.
I think that this may be another form of the system and it does not have the (OAD) pulley
Plus, they give you a picture of a brake, Regenerative Braking is different from Regenerative Charging, (Braking actually uses the Brakes - and spin-down to produce a charge voltage)


What is regenerative braking?

Regenerative braking is an energy recovery technology that takes the kinetic energy of the vehicle that is normally converted into wasted heat in the brake pads and discs during braking and instead converts it into electrical energy to re-charge the starter battery. This is made possible because of the use of smart alternators that can be controlled by the ECU when deceleration is detected. During deceleration (for example when taking your foot off the accelerator) the ECU boosts the alternator voltage output as high as 15V+ to create a burst of charge into the battery. This high voltage puts an increased mechanical load on the engine, resulting in increased engine braking, meaning less of the kinetic energy is converted to wasted heat in the pads and discs. So the deceleration of the vehicle is putting charge back into the battery, saving fuel that would otherwise be required to re-charge it.

This charge is then used to power the vehicle's electrical systems when the vehicle is accelerating or travelling at constant speed. During this time the alternator output voltage is reduced (to as low as around 12.5V), which reduces the load on the engine with a consequent reduction in emissions. Regenerative braking is only effective if the starter battery has some spare storage capacity to absorb the charge created by the alternator during deceleration. If the starter battery was fully charged the electrical energy created would be wasted and so the ECU aims to maintain the battery at around 80% state of charge (low enough to have spare storage capacity but high enough to guarantee engine starting if required).

works really really and I mean really really well in EVs - where in most cases motors have a direct connection to the drive axles and the motor when braking becomes a generator and creates a big drag as the EV batteries have a huge amount of storage capacity. And this is why some EVs have one pedal drive modes - the braking regen force is that significant.

In ICE not so much , BMW was 1st to do this regen and at the time it was estimated mpg savings could be as high as 4% - and that likely is only realized under optimal conditions. But nevertheless it's a great concept and works well for some, for others it's a death sentence for battery longevity.

 

[Bsthroop]

Decoupled is a bit misleading, to me would be like a clutch. This is like a bike pedal, always able to drive the alternator but not able to slow it down.

 

[TJC]

Just got back from a 2nd trip to the same location, 10 miles each way. Air temp 86F. Started truck and charge voltage started at 13.9V and 7 miles in dropped to 13.8V (this is float charge territory).

After the 45 minute visit (doctors office) and on the way back charge voltage quickly dropped to 13.5V and oscillated between 13.5V - 13.8V. This is right where a fully charged battery should be when on float mode.

I am satisfied that my 2020 Ford with (BMS Sensor removed) charging system will not over charge the battery.

Mind you, my truck had not been driven for 3 days.

I am a happy camper!

 

[airline tech]

I think that the only reason for decoupling is for Engine Vibration and the transition from accel to decell. So, it only decouples when the engine speed is reduced. the pulley can Freespin in the opposite direction of the rotating crankshaft, taking the load/drag off of the engine.

Now bring in coasting and the pulley recouples as the engine rotation speed is now being slowed by the load of the drive axles (engine braking effect) providing the drive for the alternator and since it is spinning slower the PCM increases the charge voltage this increased charge voltage also adds to the engine braking effect, as it is increasing the load on the engine.

This effect would explain why, if I decell and coast on a straight road, you see little boost voltage and if coasting down a hill, it continues, and the voltage ramps up higher the faster you are coasting - rotational coasting speed plays into how long and how much charge is applied as the alternator now coupled is being driven by the engine rotational speed at a much slower rate

Also again note that you have to be in the right driving condition to see this, daytime driving and warm temps above 45-50, as that is when the charging system is producing it's most fuel efficient charge (minimal) 12.2 to 12.7 volts while driving and the Regenerative Charge is needed.

The pulley couple and decouple is only mechanical.

The PCM increases the voltage set point in a Deceleration, now where the PCM picks up that it is in Deceleration mode IDK, It would most likely be the Crank and Vehicle Speed sensors reading both RPM and Vehicle Speed.

In acieration the PCM controls the voltage output the same way, it's just reducing the voltage to as low as 12.2 Volts and depending on driving condition, day or night and battery temp it adjusts the voltage to maintain the battery SOC.

So, in a way the OAD pulley does play a role in the charging system, a mechanical role only, this makes the most logical sense and the decouple of the pulley is only momentary, then recouples pretty quickly, by other descriptions it stays decoupled until you hit the gas pedal (accelerate) what is does not describe is the engine braking effect on it.

I feel confident that this is an accurate description on the system and how they relate.

Below is something I found on the F-150 forum, in a previous post the poster stated he worked for Ford and wrote the manuals on the system


Quote:
Originally Posted by Re-tired
Hard for me to believe that-
So can you give me a ROUGH-- just rough idea how much better fuel economy ( increased MPG ) that is giving us OVER
making it like it was ( no re- setting anything ) years ago when I could just swap out the battery and go-----
Really should do some reading on this site regarding BMS though admittelty have asked the right person. The main purpose for the BMS system goes back before vehicles had start/stop that used a Hall Sensor (also called BMS sensor), not the same module that attaches to the battery negative post. The BMS monitors battery conditions that provides feedback to the BCM charging control strategy. Honda had this special charging control strategy for fuel economy for about 15 years now, way before Ford. One of the BCM charging control strategies is a fuel economy mode. In that mode, the BCM commands the PCM to raise/lower voltage setpoints based on engine efficiency. At low efficiency (idling/high acceleration) the voltage setpoint is lowered to reduce drag on the engine. At high efficiency (coasting or steady state conditions), higher voltage setpoint to allow re-charging the battery. The fuel economy from this system is real, more so than the start/stop system available imo. Fuel economy figures are not publicized and not able to provide this information. This is also why I mentioned previously the BMS operation may actually hurt battery health.

When Ford introduced start/stop systems we needed a more accurate means of determining battery health and developed the sensor which mounts on the battery terminal. It is more accurate and provides temperature information. Ford doesn't want vehicle's engine turning off at stop lights if the battery is unhealthy or unable to restart.
Last edited by stormsearch; 02-26-2020 at 04:43 PM.

 

[Bsthroop]

"At low efficiency (idling/high acceleration) the voltage setpoint is lowered to reduce drag on the engine."

So the BMS adds horsepower during acceleration! For free, except battery life.

 

[got3fords]

So let my get this straight. You can disable ASS in Forscan. You can disable BMS in Forscan. Wouldn't one also disable the other? I would think disabling BMS would be better than pulling the plug, at least the ECM knows not to look for that info.

The BMS seems very temperature dependant. Today the crusing charge voltages were less as the temps were high 80's. Also, people who live in flat terrain may not see regen charging as much as those of us who have more hills. Which equals more downhill regen charging.

 

[Bsthroop]

So let my get this straight. You can disable ASS in Forscan. You can disable BMS in Forscan. Wouldn't one also disable the other? I would think disabling BMS would be better than pulling the plug, at least the ECM knows not to look for that info.

The BMS seems very temperature dependant. Today the crusing charge voltages were less as the temps were high 80's. Also, people who live in flat terrain may not see regen charging as much as those of us who have more hills. Which equals more downhill regen charging.

Yes it is one selection for both when disabling.

 

[Big Blue]

I think that the only reason for decoupling is for Engine Vibration and the transition from accel to decell. So, it only decouples when the engine speed is reduced. the pulley can Freespin in the opposite direction of the rotating crankshaft, taking the load/drag off of the engine.

Now bring in coasting and the pulley recouples as the engine rotation speed is now being slowed by the load of the drive axles (engine braking effect) providing the drive for the alternator and since it is spinning slower the PCM increases the charge voltage this increased charge voltage also adds to the engine braking effect, as it is increasing the load on the engine.

This effect would explain why, if I decell and coast on a straight road, you see little boost voltage and if coasting down a hill, it continues, and the voltage ramps up higher the faster you are coasting - rotational coasting speed plays into how long and how much charge is applied as the alternator now coupled is being driven by the engine rotational speed at a much slower rate

Also again note that you have to be in the right driving condition to see this, daytime driving and warm temps above 45-50, as that is when the charging system is producing it's most fuel efficient charge (minimal) 12.2 to 12.7 volts while driving and the Regenerative Charge is needed.

The pulley couple and decouple is only mechanical.

The PCM increases the voltage set point in a Deceleration, now where the PCM picks up that it is in Deceleration mode IDK, It would most likely be the Crank and Vehicle Speed sensors reading both RPM and Vehicle Speed.

In acieration the PCM controls the voltage output the same way, it's just reducing the voltage to as low as 12.2 Volts and depending on driving condition, day or night and battery temp it adjusts the voltage to maintain the battery SOC.

So, in a way the OAD pulley does play a role in the charging system, a mechanical role only, this makes the most logical sense and the decouple of the pulley is only momentary, then recouples pretty quickly, by other descriptions it stays decoupled until you hit the gas pedal (accelerate) what is does not describe is the engine braking effect on it.

I feel confident that this is an accurate description on the system and how they relate.

 

[TJC]

"At low efficiency (idling/high acceleration) the voltage setpoint is lowered to reduce drag on the engine."

So the BMS adds horsepower during acceleration! For free, except battery life.

It all depends where you measure the HP. Ford measures it at the engine. Dyno's measure it at the drive wheels. Gross HP is a constant. Net HP (Drive wheel HP) is minus all the drag from components and drive drive train losses.

Ford's measure never changes unless you modify the engine.

(Dyno)Drive wheel HP can and does change, based on whether the AC is running, alternator is charging, cooling fan clutch engaging / disengaging, and drive train losses.... and even tire/wheel size and weight. Even altitude, barometric pressure, and air temperature make a difference.

In physics, nothing is free!

 

[Bsthroop]

It all depends where you measure the HP. Ford measures it at the engine. Dyno's measure it at the drive wheels. Gross HP is a constant. Net HP (Drive wheel HP) is minus all the drag from components and drive drive train losses.

Ford's measure never changes unless you modify the engine.

(Dyno)Drive wheel HP can and does change, based on whether the AC is running, alternator is charging, cooling fan clutch engaging / disengaging, and drive train losses.... and even tire/wheel size and weight. Even altitude, barometric pressure, and air temperature make a difference.

In physics, nothing is free!

Wheel HP is real HP! And it adds more than a damper.

 

[TJC]

Physics is a wonderful thing... In fast cars, it is all about HP to weight ratio (and handling if your running the twisties). Take a Peek at the write up on the Ariel Atom V8.... or the Top Gear Video Here Slightly more HP than a 2020 Corvette, but much lighter at just over 1200 lbs. And it's a full 1/2 faster in 0-60 times (at 2.3 seconds) than the 2020 Corvette.

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