Chevy volt range test5/30/2023 ![]() Sometimes we forget a variation of a few tenths of a kWh in full depletion readings may arise from normal factors and not degradation. I suspect you’d be very concerned if your 2014 Volt was giving you only 8+ kWh per full charge instead of 10+ kWh, but have we ever read of many owners reporting such a drastic drop? More often it’s about battery repair because of cell balancing problems. For a 2013/2014 Volt, such degradation could drop the usable window down to 7.5 kWh. The dealer’s service department could provide a better evaluation.Ĭlick to expand.The Gen 1 battery warrantee says the battery "may degrade up to 30%" and still be within acceptable limits. Calculations using data from the maximum testable change in SOC (~65% for a Gen 1, ~76% for a Gen 2) might be adequate for providing an approximation of the existing full battery capacity. Readings for both SOC% and kWh Used might be obtainable only to 1 decimal point. I suspect, however, that the available tools can’t provide sufficient precision. Multiply by 100 to get full battery capacity. Dividing the kWh Used by the change in raw SOC gives the kWh Used for each 1% of full capacity. An OBD reader and an app to track the change in raw SOC as the kWh Used increases could be used. The Volt has no "raw state of charge" display. Loss of calibration may cause the computer to estimate that it’s time to "switch to gas" before the state of charge has actually dropped that far (i.e., it stops using grid power before the full 65/76% window has been used, and the kWh Used doesn’t reflect the whole usable window).Įvaluating your battery for degradation requires determining how much of the battery’s charge was used to obtain the kWh Used number shown on the energy usage display screen. ![]() The "Tale of Two Volts" suggests that the Battery State Estimate Algorithm may gradually lose calibration if the Volt is habitually driven only short distances and immediately recharged, and rarely driven far enough to deplete the battery (recalibrate by running through a few cycles of full charge/ full depletion). Note, for example, that the kWh Used for a full charge may decline over time for reasons other than battery degradation. That doesn’t leave much room to expand the window at the top to compensate for battery degradation, nor would I expect GM to lower the "hard floor" SOC (~15%?) at the bottom.Ī consistent kWh Used number on the energy usage display from full depletion to full depletion suggests your battery is healthy, but there are valid reasons why the kWh Used number may vary from full charge to full charge. The "switch to gas" SOC is at 20-22%, the full charge is at 96-98%, above which is a small amount of space for regen to go when fully charged. Consider, for example, that the Gen 2 Volt’s usable window is (14.0/18.4 =) ~76% of full capacity. I suspect there is no reason to think the usable window is adjusted over time to account for battery degradation. Now, it just helps to pass the time and keep me interested in thingsĮDIT: Thanks to all who responded with your thoughts and suggestions. Come to think of it, did CARB have something to do with it (mandate)?Īs far as data is concerned, I'm a junkie The curse worked to my advantage in my engineering career. And to me it was a statement of how confident the engineers were with their design. I refrained from explaining that warranties were not statements of how long something would last but was a guaranty to replacing defective parts over a period of time. I was kind of shocked when he asked in a derogatory way what he was supposed to do with the car after the GM battery warranty ran out in 8 years.get another car? His thinking was that the battery life was 8 years. I still recall having a brief conversation with another customer about the Volt when I was looking at it for the first time back in 2012. ![]() ![]() I think that GM engineers really worked on the problem and figured out how to baby the battery, both in design and construction and in environment and utilization. Judging from the averages and from the computed "miles/kWh" there has been no degradation in efficiency.Ĭlick to expand.I agree. I figured that that would show any deviance from year to year. 4.4ĮDIT: I should have pointed out that the "electric miles" and "kWh used" values are the average of the entire year. I record the data from each trip I take, whether it be 2 miles or 600 miles. On an individual basis, there are so many variables that can affect battery range that I have averaged each year’s worth of driving in the following chart in order to mitigate that problem. What parameters should I monitor to discern battery degradation? Would battery degradation manifest itself in reduced miles/kWh, or, can it only be determined by the number of miles driven before battery depletion? ![]()
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