Electric cars are supposed to supplant internal combustion-powered vehicles over the next 10-20 years. And while the sales of electric cars are growing, they remain a small fraction of the U.S. market due to their higher costs and limited charging stations.

These problems should be resolved over the next few years, with likely breakthroughs in battery technology to reduce the average cost of electric vehicle batteries. Combine that with a nationwide expansion of fast-charging stations, along with lower costs for electric motors as automakers ramp up production, and electric vehicles could reach price parity with – and maybe even cost less than – traditional cars, while becoming just as convenient to “refill”.

That’s the future many envision, but for now, EV battery packs remain the single most expensive part of an electric car. Thankfully, all-electric car batteries are covered by an eight-year, 100,000-mile warranty, so if a new or moderately used EV needs a new battery it’s possible, even likely, to be replaced for free. Better still, battery degradation is rare in modern EVs, with most of them retaining 90-plus percent of their battery capacity for a decade or more.

However, despite their impressive life span, every EV battery will eventually fail. And if it’s out of warranty, the electric car battery replacement cost will be paid by the owner. So let’s dive into electric car battery costs.

Plug-in hybrid cars, including the BMW i3, Chevy Volt, Hyundai Ioniq, and Toyota Prius Prime, have relatively small battery packs, typically between 10 and 20 kilowatt hours. Looking at automotive repair site Repair Pal shows the cost of battery replacement for these hybrid’s between $9,000 and $11,000, including labor costs.

Read more: How much is an electric car battery?