Works As Advertised
The 48 volt Luna FLX replacement battery was a simple, immediate way to increase the performance of my Gen1 FLX bike without replacing the bike's gears, chainring, or motor, which is what many owners have chosen to do. The battery does increase the overall power of the bike, in terms of speed and climbing. It also gives me the added range of having a second battery for long rides.
The big question is how overvolting the 250 watt motor will affect its nylon gears in the long run. For that, only time will tell. To prevent damage I try to keep peak watts below 700, as I understand the motor is designed for peak 650 watts. I also try to start in low gear and PAS, especially on hills. When I do this the motor gets only warm, which is a good sign.
Taking these steps means I usually ride on PAS 1-3, ride sparingly on 4-5, and reserve 5 for the flats in short bursts. With the added power I don't seem to miss riding a lot on 5.
Initial impression: battery seems to be working out well so far, taking these steps. Some riders may not want to have to baby their motors when riding, which I totally get.
One thing to note is the stock LCD display will not display the remaining battery life, as it is designed for the stock 36 volt battery. So I look at the number of bars remaining on the battery itself to determine when to recharge. The total number of watt hours on the battery is roughly the same as the 17ah FLX battery, so mileage should be around the same.