I have a couple Pulse RK9 12V electric scooters (parent company is Bravo Sports). I have not had good luck with them. One stopped running altogether and was ultimately replaced by via warranty. Another saw rapid reductions in runtime (from 40 minutes when new down to 2 minutes a few weeks later). I replaced that one as well and the same problem is manifesting with the replacement scooter.
So, my working theory is the scooter is cheaply made. I figure the worst components are the control unit and the battery. Can I modify the scooter to accept a better battery, like a Lithium Ion (to replace the 12V Lead Acid)? Do I need to also replace the control unit to operate with and charge the different chemistry battery? I'm not opposed to using an external charging unit.
I appreciate any help the members of this forum can offer. These scooters have been a disappointment for my kids and I'm trying to salvage what I can. I'm not afraid to tear it apart, replace components and splice wires.
You are absolutely correct that the battery and control unit are the weak links of the electrical system.
The failing original battery can be replaced with a fresh stock higher quality lead acid battery such as our item # RK9-BATTERY, RK9-BATTERY2, RK9-BATTERY-XR, or RK9-BATTERY2-XR, or with a LiFePO4 Lithium Ion battery such as our item # BAT-LIF12V7.5AH. This LiFePO4 battery does not require a different battery charger to be used with it, so only the original battery would need to be replaced and the original battery charger could be used to recharge the new LiFePO4 battery.
The scooter's control unit does not need to be changed when converting the scooter to using this LiFePO4 Lithium battery.
Please let me know if you have any further questions.