My charger has a single solid red light in the 25% slot and doesn't charge the battery. Fan blowing full strength. The docs on the charger seem to indicate it's "too hot" but it's definitely not too hot.
Do you have a second, known good battery that you can place on the charger to determine if it's the charger or battery? If not, give Ego a call at 1-855-EGO-5656 (1-855-346-5656) from 8:30AM - 8:00PM EST (Monday - Friday) & 10:00AM - 6:00PM EST (Saturday & Sunday).
Best to call early in the day to avoid long wait times.