Budget Battery Capacity Readout

Hoon said:
On your 2001 Nissan Leaf, could it be that the depth of discharge you are seeing is actually another layer? Just like what we see on Clarity's battery level (also shown in HondaLink app) as 100% is actually somewhere between 90%-95% or maybe even lower?

I wasn't recommending full-charge to recondition the cells, it was just for more accurate readings since @Eva Farkas sounded like the car was never fully charged for 3 years or any time recently. I would guess that it will actually wear the battery a little more since it is a deep charge and discharge, I didn't imply doing this to revive the cells. I don't know. It would be interesting to see how it reads in current state and then reading it again after one time of full charge. I would bet that you will get a more realistic reading after a recent full charge-discharge cycle which will feed that data to the BMS.
Click to expand...

The Leaf has a Coulomb counter. The reading I was using to evaluate the lower cut off was the actual Ah the car calculated as remaining, also, the voltage at which it hits the various thresholds is not going down.

Sorry, I didn't make it clear.. I wasn't saying that you were the one claiming that deep-cycling batteries helps to restore capacity. It was someone else, and may have been in the Autel thread
 
I just got Car Scanner working.

BattCap 48.44

I did not get battery reading on PDI, this is my first reading.

2018 build 1/18 Purchased 11/18
96,800 miles
1707 (+100) gallons of gas burned x 40 mpg = 72,280 HV
Calculate about 24,520 miles on EV
Full discharge and recharge most times.
Hit zero bars on battery meter (0% SOC) about 5 times
 
ClarityBill said:
I just got Car Scanner working.

BattCap 48.44

I did not get battery reading on PDI, this is my first reading.

2018 build 1/18 Purchased 11/18
96,800 miles
1707 (+100) gallons of gas burned x 40 mpg = 72,280 HV
Calculate about 24,520 miles on EV
Full discharge and recharge most times.
Hit zero bars on battery meter (0% SOC) about 5 times
Click to expand...

Wow, I think that's pretty impressive capacity preservation for the mileage. Makes me feel more comfortable about my purchase. How do you run the battery gauge down to 0? Mine always bottoms out at 2 bars
 
There are two situations that I remember getting to 0 bars:

Going up a highway hill at 78 mph with the heater running (Last week and most common).
Going up a highway hill at 78 mph in EV with a cold engine, and engine starts automatically when EV range gets to 0, but engine has to warm up before produces much electricity.
 
All - I am a legacy Touque Pro user that only recently started using Car Scanner Pro. Other than selecting Honda/Acura Hybrid in the connection profile and setting the fuel tank capacity to 7 gal, are there any other vehicle options that I should be setting up? Finally, which screen do you use most to monitor activity - Dashboard or select Live Data mode? Appreciate any tips/shortcuts that I should be using....thanks again
 
Hoon said:
Slide showing how BMS controls the depth of discharge to provide more consistent usable range to the end-user (at the expense of more wear) until the end-of-life. There's no definition of "end-of-life", kind of like "lifetime fluid".
But at least now that we can read out the actual capacity, that part is transparent.
Click to expand...

The second chart is a bit blurry on my device. Does the blue line represent using the battery from 75%-65% SOC? If so, which usage pattern would extract the most available energy from the battery, using 10% 8000+ times, or using 75% 4000+ times?
 
Landshark said:
The second chart is a bit blurry on my device. Does the blue line represent using the battery from 75%-65% SOC? If so, which usage pattern would extract the most available energy from the battery, using 10% 8000+ times, or using 75% 4000+ times?
Click to expand...
Yes, that's 75%-65%. If you stay within those range then you get 8000+ full cycles worth of energy. For example, let's say your battery has 100 Wr energy with 100% charge. If you fully drain and fully charge say 100%-0% all the time, you may only get 300 full cycles, which is 100 Whr x 300 = 30 kWr. If you use only 10% and cycle between 75%-65% then you may get 8000 full cycles worth of energy, which is 100 Whr x 8000 = 800 kWr. So it basically means you can ignore cyclic wear, and the remaining thing is calendar wear.
There are tons of research on the battery depth of discharge vs battery life. Basically, you want to avoid higher voltage levels and shallow cycle as much as possible near the middle. Most EVs have a guardband on the upper limit and lower limit to prevent premature wear.

jpkik96 said:
All - I am a legacy Touque Pro user that only recently started using Car Scanner Pro. Other than selecting Honda/Acura Hybrid in the connection profile and setting the fuel tank capacity to 7 gal, are there any other vehicle options that I should be setting up? Finally, which screen do you use most to monitor activity - Dashboard or select Live Data mode? Appreciate any tips/shortcuts that I should be using....thanks again
Click to expand...
Page 1 has the @lincomatic & @MrFixit posted the instructions on how to enable the battery capacity check through adding a custom PID. Or you can download the whole set posted by @MrFixit on post #44, it's a backup of his setup including all the custom PID for our Clarity. Thanks again to both of those guys!

I think you are supposed to use the "Dashboard" in CarScanner to monitor things.
Here's my setup, captured while pulling into my home from work. I charged to 80% at work this morning, one way is about 10.5 miles. (I use an iPhone so it's kind of hard to get the files off.)

IMG_6349 (Small).webp

lincomatic said:
Wow, I think that's pretty impressive capacity preservation for the mileage. ...
Click to expand...
But then you also have to consider his EV miles is 24.5k (at 48.44Ah). Yeah, it is still impressive. I'm curious of @Eva Farkas's 83k miles pure HV mode.
 
Got my vgate iCar Pro today and the results (with Car Scanner) is:
Clarity Touring 2018, purchased Dec 2018
26,324 miles
Battery capacity: 48.5
 
Hoon said:
If you fully drain and fully charge say 100%-0% all the time, you may only get 300 full cycles, which is 100 Whr x 300 = 30 kWr.
Click to expand...

This may be the case for a Lead Acid battery. We can’t compare the charge cycles of a LA battery to a Lithium battery.

Battle Born, for instance, has tested their Lithium batteries to 3000 full charge cycles while still retaining 80% of their original capacity. I may have run 300 full charge cycles on the Clarity, at least as much of a full charge cycle that Honda will allow.

I suppose if you plan on making 8000, 3-5 mile trips in a Clarity, keeping the battery between 65-75% might be worth the effort. Personally, I’ll take the 4000 cycles using 75% of the energy available and live with the 74% remaining capacity compared to 92%.
 
Landshark said:
This may be the case for a Lead Acid battery. We can’t compare the charge cycles of a LA battery to a Lithium battery.

Battle Born, for instance, has tested their Lithium batteries to 3000 full charge cycles while still retaining 80% of their original capacity. I may have run 300 full charge cycles on the Clarity, at least as much of a full charge cycle that Honda will allow.

I suppose if you plan on making 8000, 3-5 mile trips in a Clarity, keeping the battery between 65-75% might be worth the effort. Personally, I’ll take the 4000 cycles using 75% of the energy available and live with the 74% remaining capacity compared to 92%.
Click to expand...

We are talking about li-ion only. No confusion there.
Cycle count of 300 was just an example from consumer electronics that goes up to 4.4V in some cases. We know cells in our cars are charged up to / near 4.1V per cell for longevity.

I’m not saying you should stick with 10% DOD. It’s a trade off. If your commute is just 5% one way, why not take advantage of shallow DOD keeping it between 50%-60% or something? Keeping at 90%-100% would be harsh for the battery so you might as well just charge twice a week or so.
 
Hoon said:
If your commute is just 5% one way, why not take advantage of shallow DOD keeping it between 50%-60% or something?
Click to expand...

Frankly, because it’s just too much dicking around for little to no gain.

Hoon said:
Cycle count of 300 was just an example from consumer electronics that goes up to 4.4V in some cases. We know cells in our cars are charged up to / near 4.1V per cell for longevity.
Click to expand...

Let’s reference the chart that you provided using our Clarity PHEV battery as an example.

Using 10% of the charge and keeping the SOC between 65-75%, we would be using 1.7kWh’s per trip. It would take nearly 22 years if we made such a trip 7 days a week, to reach the 8000 charge cycle target. While we aged, we would have used 13,600kWh’s during our travels, and the battery would potentially have retained 92% of its original capacity.

Using 75% of the charge and keeping the SOC between 25-100%, realistically with a BMS this would be 15-90%, we would be using 12.75kWh’s per trip. This would take nearly 11 years of driving 7 days a week to reach the 4000 charge cycle target. In that time period, we would have used 51,000kWh’s during our travels and the battery would potentially have retained 78% of its capacity.

Both batteries would still be well above the capacity rating for a warranty claim. The second example would have allowed the owner to drive 3.75 times the mileage in half the time as the first example. So, I must ask, what is the point in trying to preserve 92% of the capacity, for 22 years, in a 17kWh battery if you are only using 1.7kWh’s to complete your daily driving?

Now as far as why our cells are charged to -4.1V. It is because they are a cell with a nominal voltage of 3.7V. That is considered 70% charged. At 4.1V they are considered to be 90% charged. They are 100% charged at 4.2V.

We shouldn’t confuse these cells with the 3.2V cells that are used in our 12V battery, which give it a nominal voltage of 12.8V. Nor should we confuse our 3.7V cells with a battery that might be used in an electronic device. Certainly, a phone or computer doesn’t have a sophisticated BMS such as what is in an EV. And those batteries are inexpensive and simple to replace. We can’t use the 300 charge cycle example that you suggested for a battery in an electronic device to compare with the life cycle of a lithium battery used for energy storage or motive power.
 
Landshark said:
Frankly, because it’s just too much dicking around for little to no gain.



Let’s reference the chart that you provided using our Clarity PHEV battery as an example.

Using 10% of the charge and keeping the SOC between 65-75%, we would be using 1.7kWh’s per trip. It would take nearly 22 years if we made such a trip 7 days a week, to reach the 8000 charge cycle target. While we aged, we would have used 13,600kWh’s during our travels, and the battery would potentially have retained 92% of its original capacity.

Using 75% of the charge and keeping the SOC between 25-100%, realistically with a BMS this would be 15-90%, we would be using 12.75kWh’s per trip. This would take nearly 11 years of driving 7 days a week to reach the 4000 charge cycle target. In that time period, we would have used 51,000kWh’s during our travels and the battery would potentially have retained 78% of its capacity.

Both batteries would still be well above the capacity rating for a warranty claim. The second example would have allowed the owner to drive 3.75 times the mileage in half the time as the first example. So, I must ask, what is the point in trying to preserve 92% of the capacity, for 22 years, in a 17kWh battery if you are only using 1.7kWh’s to complete your daily driving?

Now as far as why our cells are charged to -4.1V. It is because they are a cell with a nominal voltage of 3.7V. That is considered 70% charged. At 4.1V they are considered to be 90% charged. They are 100% charged at 4.2V.

We shouldn’t confuse these cells with the 3.2V cells that are used in our 12V battery, which give it a nominal voltage of 12.8V. Nor should we confuse our 3.7V cells with a battery that might be used in an electronic device. Certainly, a phone or computer doesn’t have a sophisticated BMS such as what is in an EV. And those batteries are inexpensive and simple to replace. We can’t use the 300 charge cycle example that you suggested for a battery in an electronic device to compare with the life cycle of a lithium battery used for energy storage or motive power.
Click to expand...
I appreciate your hypothetical example and enjoyed reading your reply. I don't know why you brought up lead-acid battery though.

Honestly, I don't think anyone would be driving on just 10% every day and expecting 22 years of service life. Something else will fail before that, and if we are talking about just the battery then there's also the calendar aging of the li-ion battery. I totally understand Honda BMS already has management going on, no dispute there.

What I wanted to point out from that graph was just the fact that less depth of discharge equates to many more cycles, directly related to the cyclic wear of the battery. For Pure EVs with much larger battery pack, it'll be much easier to maintain lower voltage levels. Why do you think Tesla has lowered their max top voltage setting? Why do they reserve the higher voltage levels for long trips only and not say it's for daily commute? I sense that you already know the answer to this, but yeah, if you don't care about some X wear on the battery after Y years, then no problem.

I guess it becomes more of a preference or mentality thing, why do some people put screen protectors on their phones? Why do some people replace engine oil every 5000 miles instead of 10000 or 15000 miles?
I just like to keep it at its best condition as I can and it's not dragging me with anything so I started paying attention to the charge level. My EVSE (JuiceBox Pro) has an app setting that's easy enough to change instantly and set the desired amount dispensed (usually set at 20% or 3-4 kWhr).

My 2013 rMBP13 still has 90% battery level remaining according to CoconutBattery. I keep it near 50% battery level as it's mostly plugged in. You can actually mask one of the signal pin on the MagSafe charger and that'll power the laptop but prevent charging the rMBP13. I also keep my iPhone battery level below 80%, and it's been really good after 1-4 years. I've done this on iPhone SE, 11, SE2. It's only a few samples, but I think it's worth doing.
 
Hoon said:
If you fully drain and fully charge say 100%-0% all the time, you may only get 300 full cycles,
Click to expand...

I brought up lead acid batteries in response to your statement above. I’ve been casually researching Lithium batteries for 2 separate applications, for our motorhome and as solar energy storage at our home. Both would replace exiting LA batteries. Of probably a dozen manufacturers, all have tested and guarantee their batteries for 2000-10,000 full charge cycles. The only conclusion that I could come to, was that you were referencing LA batteries with your statement of only getting 300 cycles.

Hoon said:
I don't know why you brought up lead-acid battery though.
Click to expand...

Hoon said:
I appreciate your hypothetical example and enjoyed reading your reply.
Click to expand...

Thank you.

I based my hypothetical example on the data from the chart that you posted. I thought the data was relevant to the batteries in an EV, so I applied that information to demonstrate the type of driving habits that would need to be practiced in order to match the results on the chart. In my opinion, it is impractical and futile to put any effort into attempting to preserve battery capacity beyond what is controlled by the BMS. I intend to use the battery as designed and will attempt to extract as much energy from the battery over its lifetime as possible.

I honestly don’t know why Tesla advises only charging to ~80%. Perhaps they have little confidence in their batteries or BMS. Or, perhaps they have concerns about fast charging over time. It is unlikely that a Tesla will ever find a spot in our garage. If it did, it would be fully charged and discharged on a regular basis.
 
Danks said:
If we do a sticky post, please use the following link for the spreadsheet:

https://docs.google.com/spreadsheet...OQIpT_YiGp9N-vnBOiSz96C2I/edit#gid=1710145002
Click to expand...

Hi Danks
Very nice spread sheet - only comment the BPC Measure type does not allow ELM327 & AP200 or even separately; only allows a b or c - don't know what that means.. also for the sake of consistency; another Canadian has put mileage in km --- I think it would be good to convert to the majority miles so the listing becomes more realistic list (23,198 km = 14194 miles)
 
JohnT said:
Hi Danks
Very nice spread sheet - only comment the BPC Measure type does not allow ELM327 & AP200 or even separately; only allows a b or c - don't know what that means.. also for the sake of consistency; another Canadian has put mileage in km --- I think it would be good to convert to the majority miles so the listing becomes more realistic list (23,198 km = 14194 miles)
Click to expand...
I added the AP200 & ELM327 option. I don't know why/how you got a b or c.

Regarding km / miles. I was figuring it was easier for everyone to just enter their odometer reading without converting. When I create the tabs for analyzing the data I will convert miles to km and km to miles so everyone can read the data in the system they are familiar with.

If someone wants to convert it themselves then that works too.
 
I added the beginnings of a Battery Capacity Analysis tab to give everyone an idea of what this will look like. Note the miles, kilometers, EV miles, and EV kilometers columns.

What is on the tab right now is the easy stuff to bring in from the Battery Capacity Data page. It will take some formulas to bring in the Vehicle Data which I will get to soon.

There are also some quick and dirty graph tabs - BPC Miles and BPC - EV Miles just to get a quick graphic look at the data.
 
@lincomatic found a few more PID's for the Clarity:
  • ES Coolant Temperature Sensor 1
  • ES Coolant Temperature Sensor 2
  • ES Coolant Temperature Sensor 3
  • ES Coolant Temperature Sensor 4
  • Input Voltage of Normal Charger
  • Output Voltage of Normal Charger
  • Charging Voltage Target
  • Cell Voltage Limit During Plug-in Charging
Attached are files for importing into Car Scanner (Refer to Post #44 for review of instructions).
 

Attachments

You must log in or register to reply here.
Back
Top