don't do that.
Each set is optimised to work together.
A 36V motor that is optimised for 15mph when run with a 48V controller is no longer optimised for 15mph but 30% higher, therefore will run at a lousy yield when climbing hills, it will shed a lot more heat and melt your plastic gears.
All the modern controllers are waterproofed with silicon sealant. There is no way you can change anything inside. If you increase the voltage, the resistor that drops the voltage from 36V to 14V for the FET drivers is going to overheat. If it blows, the controller is not repairable. The 36V controller is set for 17A. If you connect it to a 48V battery, you send 48*17A = 816W into you kit. The XF07 is not dimensioned for that amount of power. The DWG22C is but it weighs 60% more.
You can see that to handle 30% more power, the motor weighs 30%-60% more. That's the margin to guarantee that the heat won't kill the kit.
The KM529 LCD is factory set for 36V, it can't be changed.
None of our kits is dual voltage. KT kits are, not Lishui.
Sorry Whoosh, you've got a few things wrong there. Some controllers are encapsulated in resin and you can't modify them (maybe your Lishui ones are? - And obviuosly, doing something like this will invalid warranty) But most controllers on the market are not and you can mod them, as you can see from my photos. Also, if you search online you will see people doing all sorts of mods to their controllers, like modding the shunt to increase current, writing new custom firmware, modding for 36/48V operation or even higher voltages.
Also, it is not a simple resistor that drops the voltage down to drive the MOSFETS, it is a Buck convertor or similar. Otherwise you would have all sorts of drive issues going from 42V at max charge to 30V at cut off, even with a 36V pack. The drive voltage to the MOSFETS is regulated to the required voltage, whatever the battery pack voltage may be (so long as it does not go way beyond the spec of the regulating circuit).
Similarly, the voltage to the LCD is supplied by the regulator circuit on the controller, so this will be typically 5V and it doesn't care what the battery voltage is, other than what digital signal the controller is giving it for voltage display and also the signal for the controller to then shut the system down if the battery voltage goes too low.
In my experience and that of a lot of other people on the web, many motors nominally marked "250W" can easily handle 800W for significant periods of time and over 1000W for short periods. Some people even put automatic transmission fluid into their motors to enhance cooling and get them up to crazy levels of W.
But, to stop the motor burning out, you need to increase voltage and keep the current down, eg, use 48V, but use a small controller of 15A, giving 810W at peak battery charge (54V).
The speed limiter at 15.5 mph will still kick in the same, as the limiter signal is frequency, not battery voltage dependent.
What you end up with by increasing the voltage is more oomph for getting up hills and faster starts. And, if you go off road and derestrict, you will have a much higher top speed with more volts.
In terms of range, if you go to 48V you need less current to deliver the same power, so range actually improves, as resistance losses increase with the square of the current.
In terms of the nylon cogs, they will strip if you overdo the current. In my experience, keep the current down and the volts high and you will be fine up to at least 750 to 800W. Even if you do strip the cogs, a replacement set is only about £20 and you can even buy metal cog replacement kits, so it's not the end of the world.
It all depends on what the poster of the original thread wants and his reasons for going to 48V...what do they want to achieve?
