I have an ES4 with about 150 miles on it. Th range reads 28 miles however, drains significantly faster i estimate only 14 miles actual range on a full charge. I estimated this range by linearly projecting after about 8 mile ride the ride is fairly flat and I weigh 160 so I suspect there are issues with the batteries. I bought this scooter from someone else, so they may not be the batteries that came with the scooter. Below is a link to a screenshot of the cell voltages.
Below are my firmware versions.
Master Controller: V0.1.3.3
My scooter maxes at 22 MPH on flat, and I know that is above the 18 it is designed for thus I think that probably contributes some but definitely not enough for a 50% range reduction. I also don't ride it at its top speed very much during my rides. I have tried updating to V1.5.1 this did not help, I have inspected my connections and they are all good. Some of the wires are a bit frayed, and I have had to solder the black and brow wires due to areas that they frayed too much then wrapped with electrical tape. I have tried only riding with my internal battery, and this did not change the 50% reduction in range thus i am only able to travel about 8 miles only on the internal battery. I cannot rule out the batteries since I don't have additional ones to test against but at least from a voltage standpoint they seem OK but I am not very electrically knowledgeable.
I ride this scooter daily as it is my commuter to and from work, and I like to take longer rides on the weekend thus I am pretty determined to fix this issue. So any suggestions would be greatly appreciated.