144 Chapter 12 Figure 2 Cincinnati Sub-Zero thermal chamber. times 10 years, or 3650 cycles. So even at three cycles per day it would take over 1200 days (over 3 years) to complete this test schedule! One the other side of the coin, if you are testing a single cell, especially if it is a relatively small one, you may be able to achieve multiple cycles in a day. Keep this in mind as you are developing your DVP&R plan as the cycle life must generally be completed using the final production intent design instead of an early prototype level. That means that the cycle life testing may run right up to start of production depending on your testing and development plan.
Another example of a “standard” characterization test is the testing outlined in the United States Advanced Battery Consortium LLC program “FreedomCAR Battery Test Manual for Power-Assist Hybrid Electric Vehicles” (2003). The testing described in the FreedomCAR manual is focused on performance-type testing and includes: Static capacity testing—the purpose of this testing is to define the battery capacity in both ampere hours and in watt hours for a battery at a specified discharge rate. Capacity fade—shows the amount of irreversible capacity loss that a battery will experi- ence based on the above static capacity testing.
Hybrid power pulse characterization (HPPC) testing—this is perhaps the most well defined in the FreedomCAR manual. The HPPC testing is used to compare the cell or pack performance against a set of performance goals (such as the FreedomCAR goals). The HPPC test profile is a relatively simple one, it includes a short period of discharge, followed by a rest period then a short period of charging (regenerative braking). This is then repeated for a period of time ( Figure 3 ).