TP5100: 9V to 22V input, 41V output, 1.5A, 60W, 92% efficiency (lithium battery compatible)so just solar panel and tp5100.The step-up module will limit the output current to 1.5A, which is a common feature in many DC-DC converters, including step-up modules. This means that even if the solar panel can produce more current, the step-up module will regulate the output current to 1.5A, which is the maximum current and within the 1.7A max for lithium on the chargers This current limiting feature helps protect: 1. The lithium battery from overcharging 2. The step-up module itself from overheating or damage due to excessive current 3. The scooter's electrical system from excessive current draw By limiting the current to 1.5A, the step-up module ensures a safe and stable charging process for your lithium battery-powered scooter. Keep in mind that if the solar panel's output current is less than 1.5A, the step-up module will output the available current, but it will not exceed the 1.5A limit.