I have a 2014 Volt with 114,000mi. In Dec 2025 had a problem that the dealer said was failure of the main battery heater system. It cost me 5K$ to have this fixed. Now, about a month later, the car is acting strangely. When it is indicating some 8, 9, or even 20 miles left on a battery charge, it randomly changes to gas. A few times it has changed back to battery and then back to gas again, but generally not until I stop and restart. Any ideas?