When I look at my 2015 crank drive Haibike Yamaha electric mountain bike, there are three main components, the bike, the motor, and the battery.
Mine has a 400Wh battery. At the time and still now my bike shop were/are able to sell me a spare battery or replacement battery for £650. They could also sell me a replacement motor, again at £650.
My bike cost £1,750 in 2015. So the battery represented 37% of the cost of my bike, and if you bought both a battery and a motor that represented 74% of the cost of the bike. If you also bought a charger at £150, then we are up to 82% of the new price of the bike.
At those prices you might well consider buying a new bike!
I already owned a Chinese derived Oxygen rear hub electric bike that cost me £1,400.
To be honest I have had issues with both bikes, and been lucky to be able to fix the problems I have had with my Haibike myself.
But by a country mile the 2011 Oxygen is far easier and cheaper to fix with parts you can buy of ebay.
I have just bought a Yose battery for £165 which included a charger. I already have a Yose battery that is still working well after 4 years.
I also bought two motor wheels from Oxygen for £120.
The Haibike battery and charger together would cost around £800 from the bike shop where I bought my bike.
I was in essence a newbie to crank drive bikes when I bought my Haibike Yamaha and am now much more aware of the defeat technology built into it and the brick wall you will face for some simple battery problems that are easy to fix, in my case a broken charger socket.
However I have managed to keep my Haibike going, it is 7 years old, it continues to work well, and off road it is fantastic, with now 15,298 miles ridden.
I do know now that I could have a problem that I could not fix and in all likelihood not be able to find a dealer to fix.
These are big companies, Bosch, Yamaha, Shimano, who could easily put in place systems to repair or replace their ebike systems at a fair price out of warranty.
I love my Haibike but probably will not now buy another crank drive bike of a similar type with defeat technology built in that you cannot either repair yourself or have repaired by the bike shop you bought it from for a reasonable service life after you have bought it.
I would have thought any expensive electric bike should be supported with spare parts and a dealer repair facility for 10 years after you have bought it.