I think one of the most important bits of kit for an ebiker is a multi meter,they can be purchased from just £3 to £4 pounds upwards, if you want to try and solve problems yourself they are essential,for cutting out problems etc at least with a meter you can check the battery voltage as a starting point,connections can be checked for continuity,instead of trying plugging and unplugging and hopng for the best,anyway thats my tip of the day buy a multimeter id be lost without mine.