My e-bike had a bit of an overhaul yesterday. Six new batteries, three new locks, a new seat, plus checks on tires, brakes and suspension. Not bad for a total of £75.
The batteries have a year-long guarantee so, barring accidents, that should be enough to see out my remaining time in China. I've had the e-bike nearly 8 years, using it almost every day. It's lasted very well.