magsafe charger failure

I have had three magsafe chargers fail. They will attach but not light. The docking port is fine as another magsafe will attach and light.

These pricey chargers last about a year. Just long enough that the warranty is up. I am not very rough with my stuff, especially since having so many fail.

Any suggestions to prevent this? It seems the problem is most likely in the complicated "L" plug that connects to the computer but I dont

really know that. I've considered coating it in a thck layer of epoxy to prevent excessive bending, but that will likely let the cord weaken where the epoxy stops.

Thanks.