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In addition to the OBD SOC value at low charge, the cell voltage of the suspect cells is also of interest. At low voltage, it is easier to see the behavior of the bad cells. I expect they will depart from the linear part if the discharge curve earlier than the good cells.
 

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HI, just wondering, to get below 0% , for the last little bit, rather than driving around near a charger, why dont you just jack it up and let it run in the garage? Would that not be easier and avoid having the push the car to the charger? Just a thought.
 

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The easiest and most portable way to empty the battery is through the 12V DC/DC converter. Attach a inverter (1500 watt) and a portable 120V heater directly to the 12V battery at the charging station, turn on the car, and fire up the heater. It should pretty quickly drain the battery without having to drive the car presuming you start it when the display shows 0%. You can monitor the actual SOC and the actual 12V battery voltage using the OBD port.

A plus with this method is that you also get a backup power source if you lose power.

ga2500ev
 

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Discussion Starter #45
The latest download seems to show several banks of batteries at lower voltage than the others. My guess-o-meter has been showing up to 77 miles now on a 100% charge when it gets to that point, but real range (travelled plus remaining) seems to be in the 60’s with mixed town and highway driving. It seems to be adjusting somewhat but no real impact on range.

I will post the text file today.

I actually use the car, so letting it get really low isn’t easy. The dealer and Fiat still say this is all normal.

Is it expected that a full charge would typically show 84 miles or more with accessories on? Mine never failed to hit that number for the first year.
 

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The latest download seems to show several banks of batteries at lower voltage than the others. My guess-o-meter has been showing up to 77 miles now on a 100% charge when it gets to that point, but real range (travelled plus remaining) seems to be in the 60’s with mixed town and highway driving. It seems to be adjusting somewhat but no real impact on range.

I will post the text file today.

I actually use the car, so letting it get really low isn’t easy. The dealer and Fiat still say this is all normal.

Is it expected that a full charge would typically show 84 miles or more with accessories on? Mine never failed to hit that number for the first year.
In moderate temperatures (above 65 F), I would expect 84 miles or more to show on the GOM. Without accessories, I would expect over 90 miles to show up.
I don't recall if you have been tracking mi/kW. If you do, you can do some estimates on pack capacity. If you average 4.5 mi/kW and your pack has 20 kWh of capacity, 90 miles of range is reasonable to expect. If your charger has a meter that tells you the amount of energy put in during charging, you can also get an idea of where the pack is at.
 

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We really can't tell anything very accurately without knowing how far off the % gauge is: We can't go by the GUESS-o-meter, since it's extremely inaccurate. I can very easily make mine show under 80, or over 110. So range estimates have to be based on the % used to drive, or the % gained while charging. That's no good when the % gauge is wrong.

So without a sub-0% recalibration, we need to at least compare the car's % gauge to OBD %, at a fairly low level.

For example, at around 50% my car & OBD are very close, but the last time I checked when my car read 11%, OBD showed 18%. That means there's at least 7% more capacity than my car's gauge & GOM indicate. So any estimates based on that gauge are inaccurate.

I'm not sure how hard it can be to check at low %, if the car is "actually used": If it's used 20% per day, just go 4 days before charging, to reach 20%. If it's used 40%/day, go 2 days, etc... For 50% daily use, just drive a few extra miles to get it low, & it will still recharge 50% overnight, for the next day's drive.

Also:
  • There are 2 different sized battery banks within the pack, with 2 different voltages, so I just go by the minimum & max cell voltages, which usually differ by less than 20mV.
  • No pushing is needed. Just time it to park shortly befor it hits 0% (preferably on OBD).
 

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Discussion Starter #48
Managed to get to about 22% yesterday with 12 miles remaining. My consistent full charge range is 77 miles now regardless of the type of driving I'm doing, but the actual range appears to be in the mid to low 60's now. I am attaching the latest data from the OBD. The blocks of low voltage cells seem pretty consistent:

Block Voltage Cell Sums:
1: 22.16 V
2: 22.16 V
3: 18.48 V
4: 18.48 V
5: 18.47 V
6: 18.42 V
7: 18.45 V
8: 18.47 V
9: 18.47 V
10: 18.41 V
11: 18.45 V
12: 18.49 V
13: 18.41 V
14: 22.18 V
15: 22.15 V
16: 22.16 V
17: 22.15 V
18: 22.14 V
 

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Agreed 100%.

It looks to me like there may be about 6% more capacity available, than what's shown on the car's own gauges. Recalibration would make that capacity available.

The cells look about 150% as unbalanced as mine have ever been, which should reduce range, but of course that's to be expected if you always use an aftermarket charger that doesn't take it to 100%.
 

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Discussion Starter #51
I get the calibration issue, but the dealer recalibrated it every time it was in (in addition to my taking below 0% before even approaching the dealer) and it reverts to the same 70-75 max range with 100% charge the next day. That was after picking it up from the dealer with 100 mile range after calibration.

the level 2 charger is the same I had been using for over a year without any issues and I still
Top it off with the fiat 110v charger once a week.
 

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Ok, thanks for confirming you balance it to 100% with the OEM cord. Since it shows 30mV imbalance at 25%, if it shows that at 100% it would seem like 1 or more cells is bad, because my 2013 balances all the way down to about 6mV, & takes a couple of months to get to 20mV imbalance.

I seriously doubt that the dealer drove it until it hit 0%, then parked it by the charger with everything turned on for several hours, then kept checking OBD until it showed 0.00%, especially since your own OBD readout says:

"State Of Charge Adjustment In progress:
\
Target SOC (Goal): 0.00 %
\
Current SOC (BPCM SOC): 22.75 %
\
Current Change Left: 0.00 %
\
Life Number EV Adjustments: 0"
 

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"taking below 0% before even approaching the dealer" does absolutely NOTHING, unless you continue all the way until OBD hits 0.00% (or if you don't have OBD, going even longer until 13 volts at the batt terminals, or if you don't have a voltmeter, going even longer to the 12V warning on the car's display).
 

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NONE of this will give you full available range if your humidity sensor is turning on your A/C compressor, which mine & many others' did without even lighting the A/C button. It's very easy to just pull the cap straight off, stick a round toothpick in the black socket to unlock the purple plug, & yank it out. I did that 5 years ago & it's been fine ever since.
 
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