New Owner 2015 Battery Issues

[chocotaco]

Recently acquired 2015 2lt with 23,000 miles. 2 previous owners and DC charging. Battery only charges to 55-57 range tops. I try to drive with the least amount of climate as possible and as slowly/efficiently. I set up torque pro and the numbers weren't great - 12.4 kwh and 38.9 raw capacity. I took it to the dealer and let them know the battery needs to be looked at since the range is so low and it seems like the miles decrease faster than real miles traveled (I only do city driving, rarely go faster than 35 mph). They didn't charge me but said they reset the software and it should re-learn in a few months. on the way home I checked torque pro and now it shows 10.2 kwh & 32.0 Raw. Is this normal to change so quickly after a reset? Will it get better or is this just showing me how bad it actually is? Battery Warranty is good through aug next year, but I know it's a headache to go through the replacement process. Does anyone have any advice on what to expect after a reset/info on kwh and raw capacity and how it can change so much?

 

[MrDRMorgan]

I have a 2014 Spark EV and a 2016 Spark EV. Both cars have about 35k miles on the ODO and currently give about 80-85 mi on a fully charged battery using 120 VAC. This drops significantly if I use the AC or heater. You did not mention what you are seeing in terms of mi/kWh but I am assuming you are aware of what impact to mi/kWh the heater or AC has on your mi/kWh. If most of your driving is around town, try driving in L instead of D. This will allow you to use motor braking to save your brakes and increase your mi / kWh too allowing the braking force of the car's motor to add charge back into your battery. It works great once you figure it out.

 

[RSC]

I don't know why the reported capacity would go down after a visit to the dealer. I'm waiting to see whether anyone would have an explanation.

It looks to me like you will have to go through the warranty process. The only suggestion I can make is to compare the kWh numbers you get from Torque Pro to the values calculated from percentage battery used and kWh used after a full charge. 10.2 kWh is very low.

 

[Infinion]

It would seem like the 56-mile range and 10-12 kWh capacity would be quite anomalous for an odometer reading of only 23k miles, that is if the lithium battery was properly maintained by the previous owner.

Can you share some extra info since you have TorquePro?

Add a display and see if you can locate the "# Charges". How many charges has the car accumulated? Assuming each charge is a full charge, if the number is low, we can infer that either the car was left at a low state of charge for a long time, or worse, left plugged in at 100% for a long time. Both of these situations contribute to rapid lithium-ion chemistry degradation. To understand what you'd be considering as "low", you can make an approximation by taking your odometer reading and dividing it by something like the EPA's range of 82 miles, or calculate the mean/average between the brand-new EPA range and your current degraded range. If the "# Charges" is below the expected number of charges, you can draw some conclusion on how well the battery was maintained. If the number of charges is above the calculated value, it could just mean that most of those charges were partial charges. We don't get a more detailed breakdown of the nature of charge cycle wear besides that, which is greatly missed in all EVs to my knowledge. The odometer really is only one part of the story when it comes to battery health...

Another way you can verify the capacity measurement in torque pro is by fully charging the car to reset the "energy used" meter in the energy screen of your infotainment system. Then, run the car down as close to its lowest range as safely as possible. If you want a super accurate reading you can sit at your destination charger location and drain the remaining battery with heaters / AC on high with the windows rolled down, which counts. Once you're satisfied, you can compare TorquePro's capacity reading in kWh with the kWh used from the energy screen.

As a third method of verification, you can add the "Chrg HV Last(Wh)" to your display in Torque pro and see how many Wh you're able to deliver to the batteries from empty to full. This has some margin of error because some of that energy is used to run the thermal management, 12V systems, and battery balancing, but it should give you a ballpark reading, perhaps 0-10% above what the battery capacity is. For example, my capacity estimate according to TorquePro was 14.464 kWh in September (14.3 now that it's colder), but I delivered 14.93 kWh to the high-voltage bus. So that charge session delivered 3% more energy than the capacity estimate predicted, but it gives me a rough ballpark of the maximum energy that could be accepted and constrains what capacity it couldn't possibly be higher than, like 16 kWh, or even 14.93 kWh because charging li-ion batteries is not 100% efficient.

One last tip that could help you:
You can partially recondition lithium cells with a procedure based on a recent journal article whose title currently escapes me. Very simply, if you subject the lithium pack to a rapid discharge at a full state of charge, you can recover some of the lost capacity. From what I've read, one of the causes of capacity degradation is that a percentage of the total lithium ions can no longer participate in the reversible chemical reaction that takes place when you charge and discharge a Li-ion battery. Lithium ions can become trapped in their intercalation zones at the battery's electrodes. Normally, when you draw power from the battery, the usual internal electromagnetic forces from usual discharge rates are enough to readily reduce the lithium oxide and pull them out of the intercalation zones at the anode and into the electrolyte. However, when the ions become trapped, the usual/lower discharge rates and their associated forces aren't sufficient to bring the stuck ions out. So these researchers tried subjecting a lithium battery with a high rate of discharge and discovered after several cycles that the higher discharges were, in fact, enough to 'unstick' some of the ions from the anode's lattice.

I don't know if 120kW is high enough power to do this with 192 pouch cells, but you could try doing a 0-60 mph acceleration right after a few full charges and check to see if this action does anything. I didn't save the resource I'm referencing, but I'll keep an eye out to see if I can cite a C discharge rate to confirm if the Spark EV's system is truly capable of this. The Spark EV has a 96S2P pack configuration. Correct me if I'm wrong, but I believe the brand-new pack capacity is 54 Amp-hours. Therefore, the individual cell capacity should be about 27 Ah (because the pack has two cells in parallel). At full power, a 120kW discharge at 400V (assuming no voltage sag) would equate to a C rate discharge of about 5.5C. With your degraded 38.9 Ah pack, it'd be about 7.7C.

 

[chocotaco]

Thank you for this detailed and thorough response. Not gonna lie, a lot of it is over my head. I grabbed the # of charges (720), but I'm not sure what a normal amount of charges would be. Seems reasonable to me. 100 charges a year ish 2x week, especially with covid being a few of those years and having two owners. I've used 50%+ of my battery twice and charged 100% twice since the service dept reset my battery and the 10.2/32 is still the reading. Happy to provide any more torque pro metrics if you can thing of any that would be useful.

 

[JeremyWinter]

Just to clarify, for the Spark EV, charging to 100% will not degrade the battery. The battery has a 20% buffer at the top so when you are charging to 100% you are only really charging to 80%.

The Bolt EV is different as it doesn't have a buffer and allows you to charge to 100%. Normally you only charge to 80%.

 

[Infinion]

Just to clarify, for the Spark EV, charging to 100% will not degrade the battery. The battery has a 20% buffer at the top so when you are charging to 100% you are only really charging to 80%.

The Bolt EV is different as it doesn't have a buffer and allows you to charge to 100%. Normally you only charge to 80%.

Hello, I have responded to these points at your original post over at viewtopic.php?p=29147#p29147

 

[Porsche]

So more than 40% degradation? or possibly more than 50%? What are you waiting for? If you still have warranty availability, run, don't walk, to the dealer and start a warranty claim. It seems to be all over the place, but I've seen the battery, refurbished or new go anywhere from $12K, to upwards of $30k from Chevy. And yes, batteries are still available if hard to get. It certainly sounds unusual for this to happen at such a low mileage, but that's even MORE of a reason to start the warranty process NOW!! It may be a headache, but one definitely worth enduring. Think about it. You'll add five to ten years to the useful life of the car. If you ever really need to replace the battery after the warranty is over, you may as well just throw the car away. A brand new Spark battery costs five thousand dollars more than a brand new Bolt. Plus labor.

 

[Infinion]

Thank you for this detailed and thorough response. Not gonna lie, a lot of it is over my head. I grabbed the # of charges (720), but I'm not sure what a normal amount of charges would be. Seems reasonable to me. 100 charges a year ish 2x week, especially with covid being a few of those years and having two owners. I've used 50%+ of my battery twice and charged 100% twice since the service dept reset my battery and the 10.2/32 is still the reading. Happy to provide any more torque pro metrics if you can thing of any that would be useful.

I agree with Porsche above, start the warranty process.

as a final confirmation, If torque pro is giving huge variance (bolt owners see ±5 kWh allegedly), do a complete charge to 100% to reset the energy screen and discharge until 0-5% or your range indicates LOW. Then read the energy screen on the Spark's Infotainment system, and not TorquePro, to validate your results.