Budget Battery Capacity Readout

I wanted to provide an update for those who are waiting for authorization to use the Beta code.
I initially sent a batch of 18 serial numbers to Autel on 3/2. I received a reply on 3/3 that those users were authorized.

Meanwhile, I had heard from 4 more:
ajzwilli
JustAnotherPoorDriver
Nutven
Ohliuw

I sent these serial numbers to Autel on 3/3. By 3/7, I had not heard back, and I had received 5 more requests.
So, on 3/7 I re-sent the above 4 again, plus these 5 new ones:
bpratt
Ray B
Hazem Abu Asab
Dan Albrich
ptcr00

As of now (3/11) I have not heard anything from Autel about these 9 users.
It is surprising to get a 1-day response initially, and now it has been a little over a week with no response on the additional users.

I have no alternative but to just wait some more. If another week goes by with no response, I'll send the list of 9 again.
I just wanted everyone to know that action as taken, but nothing seems to be happening. I will immediately let you know if I hear anything from Autel.
 
2018 Honda Clarity (Canadian Touring version) ~134,000 km
- nearly all in EV mode
- very infrequent charging (usually level 2, short stints of 30 min or so)

Bought the V gate OBD2
Car scanner app (pro)

Installed all of Mr.Fixit's PIDs

Drum roll please....

Battery Capacity reading - 54.98

Wow! Really? So if I ever stop using my Clarity like a straight up ICE regular hybrid (when I get charging and don't need to drive 200km daily, in one go), I will still have most /all of my battery still?

That's amazing, and totally helps me decide to buy out my lease in. 11 months time!
 
Eva Farkas said:
Battery Capacity reading - 54.98
Click to expand...

You said "Nearly all in EV"... Do you really mean nearly all in HV?

Well, there have been a couple of others who's numbers just seem to be 'too good to be true'. @alter, @JimK, and now yours fall into that category. In the case of @alter, there was some reason to believe that his number may have gotten reset somehow (12V battery failure, or similar)...

Have you had any experience with a 12V battery failure / replacement?

We will have to keep an eye on you three going forward. The thought is that the vehicle will gradually re-calibrate this number. Please keep an eye on this... It will probably not change quickly, but maybe checking on the measurement once a month would make sense.

It's very interesting that in your case, you have really hardly used your battery. It has basically remained at a "low" charge level (10-15%) while operating almost exclusively in HV. Perhaps what you have experienced is almost like having the battery sitting on the shelf. Maybe the degradation that most of us have experience has been almost totally mitigated by your use-case...
 
Last edited:
MrFixit said:
...Well, there have been a couple of others who's numbers just seem to be 'too good to be true'. @alter, @JimK, and now yours fall into that category.
...
We will have to keep an eye on you three going forward. The thought is that the vehicle will gradually re-calibrate this number. Please keep an eye on this... It will probably not change quickly, but maybe checking on the measurement once a month would make sense.
Click to expand...

I second MrFixit's request that the three of you check this measurement on a monthly basis, and update us with your data. Given our small sample size, having three apparent outliers regarding battery capacity is very interesting, and worth exploring further.
 
Landshark said:
There were some conflicting statements in the post. However, it was never stated at what SOC the battery has been kept.
Click to expand...

It was stated that virtually all the [pretty high] miles were HV, with almost no charging.
Under those conditions the vehicle will sit at 2 bars virtually all the time.

You can't get that many miles in this short a time without almost exclusive use of HV.
 
Eva Farkas said:
- nearly all in EV mode
Click to expand...

This is what was stated.

MrFixit said:
It was stated that virtually all the [pretty high] miles were HV
Click to expand...

I’ve driven 700 miles in one day on 3 occasions, and only lost 2-3 bars of battery capacity. Very infrequent charging” is vague. The SOC could have been kept at any percentage. And keeping it at 10-15% SOC isn’t ideal. I’ll go out in a limb and say the reading isn’t accurate.
 
@Landshark,

You will note that I challenged the statement "nearly all in EV mode" because I felt it was simply a typo (based on a much longer post from this individual earlier in the thread that was contradictory). And, the fact that "nearly all in EV mode" in entirely inconsistent with 134K km, at 4K km per month over the course of 3 years (when this person rarely charges). I am using my best judgement to interpret multiple posts that are not fully consistent.

In any event, rather than argue about facts that are clearly inconsistent, let's do the prudent thing and watch what happens with this vehicle over a longer term because this one (and the other two that seem to have zero degradation) are clearly out of character.
 
MrFixit said:
In any event, rather than argue about facts that are clearly inconsistent,
Click to expand...

No argument. Just going by what was said. I agree that the described driving habits and patterns indicate primarily HV mode driving.

I would say that based in my 700 mile trips, it would seem possible to drive 2000-3000 miles, in HV without charging, and still have a battery at ~50% SOC. An occasional bit of L2 charging could bring the battery to 75-80%. It is also entirely possible that the owner drove around most of the time with depleted batteries. I just wouldn’t make such an assumption.
 
MarkClarity said:
How about this for a theory: The battery capacity only updates after a full charge to 100% where the cell leveling occurs, and that info is used to re-calculate battery capacity.
Click to expand...

Yes, I have been thinking about this myself. It is clearly impossible to measure the full battery capacity if you never traverse the full range of charge. There may be certain operational scenarios that result in never being able to update this value, and maybe that causes a false reading to linger.
 
I think bringing the Clarity HV battery to 100% (actually about 90% of the absolutely full SOC given how the Clarity BMS works) may not be enough to reset the Battery Capacity value. For many Li-ion systems (especially laptops), the BMS requires a full charge from near 0% (about 10% of an absolutely depleted SOC for the Clarity BMS) to reset the battery capacity value.

Of course, this can be tested for the Clarity by taking a Battery Capacity measurement, along with the starting and ending SOC, for a series of charges. For these purposes, it would be nice if the HondaLink app would give the Battery Capacity along with the SOC. This would make such a study much easier to do.

LeoP
 
MarkClarity said:
How about this for a theory: The battery capacity only updates after a full charge to 100% where the cell leveling occurs, and that info is used to re-calculate battery capacity.
Click to expand...

That’s definitely a theory. If true, it would imply that the battery capacity reading for any battery not recently fully charged would not be accurate. If we apply that to owners who diligently keep their battery between, say, 30-80% SOC, they would never get an accurate reading.

I’ll propose a theory from an alternative universe. Sensors measure current over time (Ah) and compare that to a percentage increase in SOC over the same time period, to calculate an Ah rating for the battery. Of course, charging from 0-100 isn’t completely linear, but the software should be able to compare a charge from 40-60% on a new battery, with a charge from 40-60% on a seasoned battery. Just a theory.
 
The graph of SOC vs. li-ion cell voltage is fairly flat (near zero slope) between 80% and 20% SOC. This makes for a great deal of uncertainty in determining SOC from cell. The BMS usually gives out SOC from knowing the battery capacity and then coulomb counting to know the SOC (from a starting point of a full charge event). To get the battery capacity, the BMS must be fairly certain of the SOC so a charge event from and to points on the SOC vs. cell voltage plot where the SOC has less error is needed. Thus, a charge event from above 90% SOC to below 10% SOC is usually needed for the BMS to reset the battery capacity value.

LeoP
 
2018 with 35k miles. 70 mile daily commute (with the exception of weekends.) Nightly charge on a 16a level 2 charger. I don't charge on w/e's because I don't need to. I should add that I don't baby this thing. I average 76 mph on the freeway and I live in Hilly San Diego. I MIGHT get 36 miles on a charge.
47.34.
 
leop said:
The graph of SOC vs. li-ion cell voltage is fairly flat (near zero slope) between 80% and 20% SOC. This makes for a great deal of uncertainty in determining SOC from cell. The BMS usually gives out SOC from knowing the battery capacity and then coulomb counting to know the SOC (from a starting point of a full charge event). To get the battery capacity, the BMS must be fairly certain of the SOC so a charge event from and to points on the SOC vs. cell voltage plot where the SOC has less error is needed. Thus, a charge event from above 90% SOC to below 10% SOC is usually needed for the BMS to reset the battery capacity value.

LeoP
Click to expand...

We’re measuring mV’s. While 3.9V to 3.6V doesn’t sound like much, there are 3000 incremental measurements available that can be used to correspond to a SOC percentage between 80% and 20%.

Am I missing something here?

4F1D8D52-DB5E-4053-BE2A-CEE29DD36F9D.gif
 
First, there is just 300 mV difference from 3.9V to 3.6V. Second, the chart shows cell voltage while being discharged at various discharge rates. At zero discharge, there is nominally about 100mV between 80% and 20% SOC for a typical li-ion cell. Finally, there is an error in measuring an individual cell voltage (and on measuring the pack voltage). The precision of the measurement (say 1mV) is usually less than the accuracy (less accurate than 1mV). It is not that accurate to determine the SOC from voltage measurements over only parts of the 80% to 20% SOC range.

And, of course again, we can look at the change in battery capacity over time as the Clarity battery is charged many times if we collect data (starting SOC, ending SOC, kW of charging energy, and the battery capacity before and after the charging event) for each charging event. I actually record all the data except the battery capacity for each charging event for our Clarity. I doubt I will hook up the AP200 or Elm327 for each charging event. That is why I lamented the fact that HondaLink does not provide the battery capacity.

LeoP
 
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