Greetings from South Carolina. I recently purchased a 2000 Insight MT. The battery was that 4 bars SOC but never showed charging or increased on its first trip. I reset the computer yesterday afternoon and it started charging. I revved it to 3K to let it fully charge during which the IMA and check engine light came on. Codes 73 and 78. Cell too hot and battery deterioration. It was 95f/35c outside with no breeze and the car was just sitting in the yard charging. I reset the computer again last night. Today I've driven it ~200mi and the battery is staying near a full charge but doesn't give any assist or show charging while coasting. No check engine or IMA lights have reappeared and the car is getting 65+ mpg. I hate to drop big bucks into the battery when the only time it showed fault codes was when charging under adverse conditions. Any ideas if it's truly a bad battery? Could it be something else? Thanks for any help.