 They are not alone. EV charging companies have focused on improving charger performance over the past year as charging setbacks have hurt EV sales. A fifth of charging attempts failed at non-Tesla chargers in the first quarter of this year, according to J.D. Power. Meanwhile, Tesla superchargers, known as the most reliable, have only had a fail rate of 5%. Electrify America will update most of its more than 4,000 charging ports this year.