Loss in power?

[ebike445654]

About a month ago I got an ebike, pretty happy with it, but it's suddenly started to drop in power. Hills have started to become a bit of pain, but because it's still technically working, Halfords won't do anything to help. The tires are a good pressure and the brakes aren't sticking, any Idea why this might be happening?

[hemo]

So which bike did you buy ?