Lower Amp charging healthier for battery?

[greenne]

Yep, my excel was put together in 2 minute at work on lunch. Sloppy. Thanks for recognizing and correcting, I sincerely appreciate that.

However my point was more that the size of battery is not relative. The amount of miles driven and efficiency of the vehicle is.

And the main point is $70 is real money, and could change someones decision if the rate of charge made a difference on efficiency.




My argument has nothing to do with 240v vs 120v. Yes 120v is inadequate for 95% use cases of charging the lightning. My point was you have stated several times that 120v charging does not warm the battery and does not serve a benefit. You are 100% wrong unless you have data to show me otherwise.

My very brief write up on 120v stated the following.

- 15 amp connecting using AMPRoad EVSE set to 16 AMP
- Charging at 11.2 amps (per Lightning 120v limitations)
- Plugged in at 9:38 PM (65% SOC, 71.65 kWh)
- Start Temp: HVB Min 41 F/ HVB Max 42.8
- Unplugged at 7:07 AM (12.55kWh used) (70.5% SOC, 82.63kWH)
- Temp: HVB Min 53.6 F/ HVB Max 55.4
- Preconditioning was set occur at 6:55
- Ambient Garage temp was 43 F the whole time.
- Summary added ~12.5 F in 10h 30m. 11 kwh added

My conclusion: Even 120v charging is a temperature benefit. Since Only 1.5kWh was "lost" between what the charger used and what the battery gained I would conclude that 120v was enough to warm the battery a decent amount ~12.5F.

Could there be more loss at colder temps that then makes 120v less practical? Maybe I dont know that. I'd love for less conjecture on the matter and more data.

All this said... Since you seem to have all the answers please do us all a solid and answer these questions for me and others that have been wondering similar things about their trucks.

1) At what low temp does the truck warm the battery for protection when unplugged.

2) At what high temp does the truck cool the battery for protection when unplugged.

3) At what low temp does the truck warm the battery for protection when plugged in. Does a charging schedule affect this trigger point or not?

4) At what high temp does the truck warm the battery for protection when plugged in. Does a charging schedule affect this trigger point or not?

I have decided that I don't like hooking the truck up every night to 48A to top off. (I got my reasons). Up until now, I have been going from full-20% and then doing one deep charge about 1x every 5-7 days. I understand if I leave it out in the cold I lose range each day and am OK with that as my commute is ~18mi each way(36mi per workday).

So here's my question--

If I plug up to 110v overnight and assume I get minimal charging(for this scenario lets assume 0% added and all the energy goes towards preconditioning--warming--the battery)...

Will the increased efficiency on my drive due to a warm battery (say I go from 1.8 mi/keH to 2.0) be more energy it took to warm the battery(overnight energy cost)?

Another way to put this..is it worth it to plug into 120v outlet if the only thing I am getting is battery warming for increased efficiency on the morning drive?

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[TaxmanHog]

I have decided that I don't like hooking the truck up every night to 48A to top off. (I got my reasons). Up until now, I have been going from full-20% and then doing one deep charge about 1x every 5-7 days. I understand if I leave it out in the cold I lose range each day and am OK with that as my commute is ~18mi each way(36mi per workday).

So here's my question--

If I plug up to 110v overnight and assume I get minimal charging(for this scenario lets assume 0% added and all the energy goes towards preconditioning--warming--the battery)...

Will the increased efficiency on my drive due to a warm battery (say I go from 1.8 mi/keH to 2.0) be more energy it took to warm the battery(overnight energy cost)?

Another way to put this..is it worth it to plug into 120v outlet if the only thing I am getting is battery warming for increased efficiency on the morning drive?

Might try an a & b study over a couple of weeks to see the impact, though highly variable weather conditions might distort your results.

One day results:
Savings on improved performance $0.494 (2KW in my market of 24.7 cent a KW)

Charging or minimal heating for 12 hours on the 120v FMC ~ 17 KWH * 0.247 = $4.27

 

[greenne]

Might try an a & b study over a couple of weeks to see the impact, though highly variable weather conditions might distort your results.

One day results:
Savings on improved performance $0.494 (2KW in my market of 24.7 cent a KW)

Charging or minimal heating for 12 hours on the 120v FMC ~ 17 KWH * 0.247 = $4.27

I'm unclear on this.

So what your'e saying is I use 17 KwH to warm the battery, but save only 2Kw in increased performance? Would it really take 17KW to warm the battery and not get any actual charging?

 

[TaxmanHog]

I'm unclear on this.

So what your'e saying is I use 17 KwH to warm the battery, but save only 2Kw in increased performance? Would it really take 17KW to warm the battery and not get any actual charging?

I'm not sure exactly how much energy will be consumed, especially if the truck BMS says it's too cold to charge and try's using the 1.4KWH per hour just to get the temps warm enough to kick off charging, maybe the residual heat in your pack upon arriving home, will be enough to allow the energy to go to storage, of which assuming the 36 mile round trip drive you will need around 18+KWH to replenish the spent energy.

If you restrict charging, but plug in just for potential warming, it's not clear how much energy your truck might consume if any for a period of ~12 hours, assuming 6pm to 6am at home time YMMV

A good way to determine how much energy you captured for storage, would be compare it to your current regimen of once a week charging, how much energy is needed at the end of the week to get to your desired SOC to start a new week

 

[greenne]

I'm not sure exactly how much energy will be consumed, especially if the truck BMS says it's too cold to charge and try's using the 1.4KWH per hour just to get the temps warm enough to kick off charging, maybe the residual heat in your pack upon arriving home, will be enough to allow the energy to go to storage, of which assuming the 36 mile round trip drive you will need around 18+KWH to replenish the spent energy.

If you restrict charging, but plug in just for potential warming, it's not clear how much energy your truck might consume if any for a period of ~12 hours, assuming 6pm to 6am at home time YMMV

A good way to determine how much energy you captured for storage, would be compare it to your current regimen of once a week charging, how much energy is needed at the end of the week to get to your desired SOC to start a new week

It may be worth exploring.

If we take the previous "test" by @luebri we get this--

"My very brief write up on 120v stated the following.

- 15 amp connecting using AMPRoad EVSE set to 16 AMP
- Charging at 11.2 amps (per Lightning 120v limitations)
- Plugged in at 9:38 PM (65% SOC, 71.65 kWh)
- Start Temp: HVB Min 41 F/ HVB Max 42.8
- Unplugged at 7:07 AM (12.55kWh used) (70.5% SOC, 82.63kWH)
- Temp: HVB Min 53.6 F/ HVB Max 55.4
- Preconditioning was set occur at 6:55
- Ambient Garage temp was 43 F the whole time.
- Summary added ~12.5 F in 10h 30m. 11 kwh added "
----------------
It appears like 11 KwH was added to the truck in the form of charge....12.55 was the total amount pulled by the EVSE.

1.55 KwH that can either be loss and/or the amount of energy consumed to warm the battery from 41f -->53F.

 

[TaxmanHog]

It may be worth exploring.

If we take the previous "test" by @luebri we get this--

"My very brief write up on 120v stated the following.

- 15 amp connecting using AMPRoad EVSE set to 16 AMP
- Charging at 11.2 amps (per Lightning 120v limitations)
- Plugged in at 9:38 PM (65% SOC, 71.65 kWh)
- Start Temp: HVB Min 41 F/ HVB Max 42.8
- Unplugged at 7:07 AM (12.55kWh used) (70.5% SOC, 82.63kWH)
- Temp: HVB Min 53.6 F/ HVB Max 55.4
- Preconditioning was set occur at 6:55
- Ambient Garage temp was 43 F the whole time.
- Summary added ~12.5 F in 10h 30m. 11 kwh added "
----------------
It appears like 11 KwH was added to the truck in the form of charge....12.55 was the total amount pulled by the EVSE.

1.55 KwH that can either be loss and/or the amount of energy consumed to warm the battery from 41f -->53F.

Net losses for sure, and the temp increase was from the chemical reaction of adding more charge to the cells

Side question, looking at your SOC % and inferred KWH on pack, does not compute to 131KW max.

How are you getting 65% = 71.65KWH and 70.5% = 82.63 KWH ?

I would compute 65% = 85.15KWH to 70.5% = 92.36 KWH, pack energy added 7.205 KWH, the balance of actual AC drawn through the EVSE are for conversion losses at the charging inverter on the truck, do you have an AC energy monitor to determine exact energy consumed by the EVSE?

 

[luebri]

Net losses for sure, and the temp increase was from the chemical reaction of adding more charge to the cells

Side question, looking at your SOC % and inferred KWH on pack, does not compute to 131KW max.

How are you getting 65% = 71.65KWH and 70.5% = 82.63 KWH ?

I would compute 65% = 85.15KWH to 70.5% = 92.36 KWH, pack energy added 7.205 KWH, the balance of actual AC drawn through the EVSE are for conversion losses at the charging inverter on the truck, do you have an AC energy monitor to determine exact energy consumed by the EVSE?

Yes one of the things I realized in the midst of these tests over the weekend is that using the car scanner app (as noted by @Firestop on a previous thread linked below ) is there is a disconnect between SOC % and the "energy" field (kWh available?) when viewing using the Car Scanner app.

https://www.f150lightningforum.com/...attery-and-range-telemetry.11602/#post-299666

At this point without an explanation as to why, what I do know is that the SOC Display field does align with the truck and I can see it down to the decimal so that is what I would rely on without being able to trust the "energy" field as show.

In that case (70.5 - 65.0) = 5.5% (additional SOC Display %) * 131 = 7.205 kWh gained. Even though the Car Scanner app stated 11 KwH gained.

The AmpRoad charger said I used 12.55 kWh in that time period.

This however was with Precondition set at 6:55 and not unplugging until 7:07. So a good deal of the "loss" was going to heating the Cabin as well as the battery and the charge. That said if heat the cabin from the 120v wall plug or from the battery you are using kWh no matter what.

I will also say if you do a "is warming worth it" comparison it should only be on the "lost" kWh not on the used.


12.55 kWh from the wall total used.
-7.205 kWh added to battery.
- 1.255 - Inherent loss of kWh from any charging ??? ~10% (just a guess, but I include this because you are going to have some loss any time you add kWh no matter what)
=
4.09 "lost" kWh. (went to warming the cabin with the wall instead of battery during drive)

If using a .2 MPK benefit # (just a guess) you would need a ~20 (20 x .2 = 4) mile morning drive to make it make sense just from a drive efficiency standpoint.

For my personal stance is it worth 110v warming vs nothing at all. A definitive hell yes!!!

- 4.09 kWh * $0.07806 = (off peak TOU rate) = $.32 (your rate may may effect your decision)
- Warm Cabin > Cold Cabin
- Less overall cycles on the battery over time with better drive efficiency
- When is your next drive? If battery temp only drops ~1 C (per Darren Palmer) over an hour then your next drive could and likely would be less efficient as well if you had not warmed.
- IMO - Ideal battery operating temp... is just that. Ideal. The more time closer to the ideal temp the better for battery health.
- Ford has explicitly recommended you do it

This is another example of where the benefit of doing a study on loss % at different charging rates would be beneficial which I may be able to do with the FCSP charging insights.

My hypothesis so far is, if you believe in depleting the battery instead of topping off every day, that splitting the difference would be better than nothing at all regardless of charging rate. My guess is 80A loses the least % specifically in cold temperatures, but that is a guess.

What do I mean by splitting the difference? If you typically deplete 20% a day. Charge 5 or 10% a day and SCHEDULE IT RIGHT BEFORE YOUR DEPARTURE and if you are using preconditioning blend that time frame into your precondition time.

This way you can get both benefits, an incremental warm from charging and still have some accumulating battery depletion for an occasional longer charge session.

 

[greenne]

Yes one of the things I realized in the midst of these tests over the weekend is that using the car scanner app (as noted by @Firestop on a previous thread linked below ) is there is a disconnect between SOC % and the "energy" field (kWh available?) when viewing using the Car Scanner app.

https://www.f150lightningforum.com/...attery-and-range-telemetry.11602/#post-299666

At this point without an explanation as to why, what I do know is that the SOC Display field does align with the truck and I can see it down to the decimal so that is what I would rely on without being able to trust the "energy" field as show.

In that case (70.5 - 65.0) = 5.5% (additional SOC Display %) * 131 = 7.205 kWh gained. Even though the Car Scanner app stated 11 KwH gained.

The AmpRoad charger said I used 12.55 kWh in that time period.

This however was with Precondition set at 6:55 and not unplugging until 7:07. So a good deal of the "loss" was going to heating the Cabin as well as the battery and the charge. That said if heat the cabin from the 120v wall plug or from the battery you are using kWh no matter what.

I will also say if you do a is "warming worth it" comparison it should only be on the "lost" kWh not on the used.


12.55 kWh from the wall total used.
-7.205 kWh added to battery.
- 1.255 - Inherent loss of kWh from any charging ??? ~10% (just a guess, but I include this because you are going to have some loss any time you add kWh no matter what)
=
4.09 "lost" kWh. (went to warming the cabin with the wall instead of battery during drive)

If using a .2 MPK benefit # (just a guess) you would need a ~20 (20 x .2 = 4) mile morning drive to make it make sense just from a drive efficiency standpoint.

For my personal stance is it worth 110v warming vs nothing at all. A definitive hell yes!!!

- 4.09 kWh * $0.07806 = (off peak TOU rate) = $.32 (your rate may may effect your decision)
- Warm Cabin > Cold Cabin
- Less overall cycles on the battery over time with better drive efficiency
- When is your next drive? If battery temp only drops ~1 C (per Darren Palmer) over an hour then your next drive could and likely would be less efficient as well if you had not warmed.
- IMO - Ideal battery operating temp... is just that. Ideal, the more time closer to the ideal temp for the the better for battery health.
- Ford has explicitly recommended you do it

This is another example of where the benefit of doing a study on loss % at different charging rates would be beneficial which I may be able to do with the FCSP charging insights.

My hypothesis so far is, if you believe in depleting the battery instead of topping off every day, that splitting the difference would be better than nothing at all regardless of charging rate. My guess is 80A loses the least % specifically in cold temperatures, but that is a guess.

What do I mean by splitting the difference? If you typically deplete 20% a day. Charge 5 or 10% a day and SCHEDULE IT RIGHT BEFORE YOUR DEPARTURE and if you are using preconditioning blend that time frame into your precondition time.

This way you can get both benefits, an incremental warm from charging and still have some accumulating battery depletion for an occasional longer charge session.

I have a few reasons why I don't like to top up overnight at 48A. Most concerning is the fact the truck will reach the charge limit sometime in the middle of the night. I know that the software is supposed to stop charging at the user defined "limit, but also that sometimes that doesn't work and the truck charges to full. Then, there is the issue of the truck sitting at full. 100% on a 48A charger. Yes if everything works, its a non issue. But why run that risk? (I also take my cell phone off the charger when it reaches 100%). I'm also not keen with going from 0-48A-0 on the circuit each day.

If I can get the main benefit of keeping it plugged in(battery conditioning) on a 120v wall outlet along with at least a few miles of battery charge.. then that works for me. Even if I were to plug in at 6pm when I get home and unplug at 7am the next morning, I'm only going to recover part of my commute.(36mi/day). I'll never reach that upper "bumper", no worries about something going awry and the battery or EVSE getting fried. I will still need to deep charge it, but perhaps its now every 7-10 days vs every 4-5 days. Also, it keeps the battery in the 20-80% range longer than linearly running it down from full. It also limits the load on the house electrical at any one time.

Seems like a good strategy to me.

 

[luebri]

I have a few reasons why I don't like to top up overnight at 48A. Most concerning is the fact the truck will reach the charge limit sometime in the middle of the night. I know that the software is supposed to stop charging at the user defined "limit, but also that sometimes that doesn't work and the truck charges to full. Then, there is the issue of the truck sitting at full. 100% on a 48A charger. Yes if everything works, its a non issue. But why run that risk? (I also take my cell phone off the charger when it reaches 100%). I'm also not keen with going from 0-48A-0 on the circuit each day.

If I can get the main benefit of keeping it plugged in(battery conditioning) on a 120v wall outlet along with at least a few miles of battery charge.. then that works for me. Even if I were to plug in at 6pm when I get home and unplug at 7am the next morning, I'm only going to recover part of my commute.(36mi/day). I'll never reach that upper "bumper", no worries about something going awry and the battery or EVSE getting fried. I will still need to deep charge it, but perhaps its now every 7-10 days vs every 4-5 days. Also, it keeps the battery in the 20-80% range longer than linearly running it down from full. It also limits the load on the house electrical at any one time.

Seems like a good strategy to me.

Awesome! As a whole, nothing wrong with your thought process.

Ideally the scheduling gets more robust for you and for others.

For me... charging scheduling with FCSP has worked accurately 90% of the time. My normal plan is setting narrow charge window starting at 4 or 5 AM with rate of 48A or 60A for my preconditioned 7 AM departure.

Reason being, my guess so far is that is a narrow window of 48A or higher charge is more efficient then longer 120v charge and my data says it would get it all the way to the target temp and not just closer.

 

[wighty]

For the car, I don’t expect 80A charging to be any worse for it than 48A, it’s so minuscule compared to how much even gently accelerating or maintaining your speed uses.

For sure, I implore everyone in this thread worrying about it to hook up an OBD II adapter and monitor the power coming out of the pack (hint: what's your max rated HP converted to kw?), and similarly how much power is generated going into the pack with regenerative braking. Charging at 11.2kw is nothing.

 

[GoodSam]

"Charging at 240 volts is cheaper than using 120 volts --
Charging at a higher rate is actually cheaper than charging at a slower rate. Your Tesla needs to power an inverter that translates your home’s AC energy into DC energy that is stored in your batteries. Powering that inverter uses quite a bit of energy, so the longer it's running the more electricity you’re using so the faster you can charge, the less time you need to run the inverter. Charging at 240 volts is about 12% more efficient than charging at 120."
top-tesla-tips-you-may-not-know

Any data on the Ford inverter(s) "wasted energy" just to maybe keep the inverter on? I can see the efficiency of transformers being critical (like desktop computer power supplies varying efficiencies), but is inverting to DC wasting energy in the form of heat no matter the load it is handling? What is the sweet spot for Amp load and inverter excess run time? My Tesla wall connector sure puts out a lot of heat, maybe a 40F rise in temp at 40A from ambient, which I think is excessive resistance in its contactors. Not sure how what proportion of kW losses that is. Is heat the only indication of inefficiency going on?

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