Never needs batteries, this quality twin head shaver can be charged-up 3 ways including by dynamo (wind-up!, mains power or via USB (from your computer). A very versatile shaver ideal for those on the move and where power options are unknown, unreliable, or unavailable. Replacement heads are available for less than a fiver.
This is on sale in another eco-store today for £24.99, so I reckon £7 (less with Quidco) is a good deal - even if you only keep it in the car, use it for overnight stays, or for overseas holidays. Review states the shaver only needed 2 minutes winding to charge it, after a fortnight's use.