Same old Story-Cmax Energi has an inept thermal regulatory system

[Billyk24]

Took photos of near the start of a 20 mile drive home -18.8 miles on state highway with 55 mph speed limit and almost the finish.  Scanguage II is displaying BAT-hvb temp- and the cabin temperature which drops significantly while driving with the AC on full blast.    No temperature change in the HVB.     Not much one can do to reduce the heat of the battery pack when it heats up and it is the summer time. 

[Billyk24]

A Facebook reply from a Phoenix owner:                   I’ve 138k on my 2013 Hybrid, live in the Phoenix area, and my garage temp at 6:49 am is 90F (outdoor temp at 79F which will rise over the next few months). HVB temp = 90 F. Most of our daily trips are short distances (1-2 daily less than 8 mile round trips) and AC not on long enough to cool HVB but a few degrees. HVB temp stays between 90- 95 F during the summer months with AC set around 73F. I compared my HVB performance with the INL test vehicles at 105k miles (one of the INL test point for HVB capacity). My HVB tracks the HVB degradation of the average of the test vehicles (operated in Phoenix) which is about 8%. Since cycling degradation of the Hybrid HVB would be a lot less than the Energi since normally cycling would be between about 38-55%, my guess is the majority of my degradation is heat related. Now, what I have noted over the years, there is no loss of the HVB operating range in kWh. This apparently is because the control algorithms are operating at the same voltage levels when new and aged. So, as the storage capacity falls because of degradation, the SOC range expands resulting is about the same kWh of operating range. But in the Energi, since the HVB at full charge is at voltage very near the maximum voltage, there is virtually no “room” to expand the operating range at the top end for degradation and thus, usable EV kWh declines. Bottom line: I know of no Hybrid owners who had performance issues with HVB degradation (temp or otherwise) after hundreds of thousands of miles.

 

for comparison to another hybrid vehicle-my 2016 RAV4 has a usable SOC 38-78.