More public chargers are the obvious long-term solution. About half of the 330,000 electric vehicles in this country are registered in California, and Gov. Jerry Brown wants to increase that number to 1.5 million by 2025. He has pledged a sharp increase in charging stations. Right now, there is roughly one public charger for every 10 electric vehicles — about 15,000 in California and 33,000 across the country, according to ChargePoint, one of the biggest charging-station companies. (There are thousands of other, unofficial charging spots that are essentially wall outlets that businesses or homeowners have made available for public plug-in).