Battery Warranties Compared

Looking at Mitsubishi's i-MiEV website, our i-MiEV battery warranty is rather nebulous: transferable 8-year/100,000-mile limited warranty; however, to date and to Mitsubishi's credit, in the few instances there were identified i-MiEV battery issues, Mitsubishi has unhesitatingly replaced those battery packs.

While perusing the Kia Soul EV website , here is the Kia Soul EV battery warranty -

Lithium-Ion Polymer Battery Capacity Coverage
The Lithium-Ion Polymer Battery (“EV Battery”) Capacity warranty coverage period is 10 years or 100,000 miles from the Date of First Service, whichever comes first, for capacity loss below 70% of the original battery capacity. This warranty covers repairs needed to return battery capacity to 70% of original battery capacity. If possible, the EV battery components will be repaired or replaced, and the original EV Battery will be returned to the vehicle. If necessary, the EV Battery will be replaced with either a new or remanufactured Lithium-Ion Polymer Battery. Any repair or replacement made under this Lithium-Ion Polymer Battery Capacity Coverage may not return your Lithium-Ion Battery to an “as new” condition with the original 100% battery capacity. However, it will provide the vehicle with an EV Battery capacity of New Vehicle Limited Warranty at least 70% of the original battery capacity. This Lithium-Ion Battery Capacity Coverage is subject to the exclusions listed under the section “What is Not Covered.”

Here are Kia's "What Is Not Covered" exclusions, which further corroborate a few maxims regarding care and feeding of our batteries that we've come to realize over the last few years.

"EV System and Lithium-Ion Polymer Battery" damage or failures resulting from or caused by:
- Exposing a vehicle to ambient temperatures above 122F (50C) for over 24 hours.
- Storing a vehicle in temperatures below -22F (-30C) for over seven days.
- Leaving your vehicle for over 14 days where the Lithium-Ion Polymer Battery reaches a zero or near zero state of charge.
- Physically damaging or intentionally attempting to reduce the life of the Lithium-Ion Polymer Battery.
- Exposing the Lithium-Ion Polymer Battery to contact with a direct flame.
- Immersing any portion of the Lithium-Ion Polymer Battery in water or fluids.
- Opening the Lithium-Ion Polymer Battery enclosure or having the Lithium-Ion Polymer Battery serviced by someone other than a Kia certified EV technician.
- Neglecting to follow correct charging procedures.
- Use of incompatible charging devices.
- Incidental or consequential damage caused by the failure to repair an existing problem

The specificity and perhaps lessons-learned from Nissan's Leaf experience is interesting.

I haven't had a chance to look at a Kia Soul EV manual to see what they have to say about "correct charging procedures".

Regarding the Volkswagen e-Golf warranty, from the media.vw.com website:

The 2015 e-Golf is offered with Volkswagen’s five-year/60,000-mile (whichever occurs first) powertrain limited warranty and three-year/36,000-mile (whichever occurs first) new vehicle limited warranty. The e-Golf also has a battery limited warranty that covers eight years or 100,000 miles against 70 percent capacity.

From the Nissan Leaf website, Lithium-ion Battery Gradual Capacity Loss:

In addition to the Lithium-ion Battery Coverage for defects in materials or workmanship (96 months/100,000 miles), the Nissan LEAF® Lithium-ion battery is also warranted against capacity loss below nine bars of capacity as shown on the vehicle’s battery capacity level gauge for a period of 60 months or 60,000 miles, whichever comes first. See your Owner's Manual for tips on maximizing battery life and capacity.

Nine out of twelve bars is 75%, but only for 60,000 miles. Unlike the i-MiEV, the capacity bars on the Leaf show the reduction in capacity. On the i-MiEV, our best guess is that capacity reduction takes away from the below-zero "turtle" range.

Hmmm, maybe looking at every production BEV's Owner's Manuals might provide some new hints about the care and feeding of our Lithiums...