My son got this adorable 6v ride on chinese manufactured motorcycle for christmas from his Grandpa. It is powered by a single motor driving 1 wheel through a small plastic gearbox. it can go forward and reverse and the battery is a 4.5AH SLA battery.
It was awesome for the first two rides. Then it was “Slow dad”.
Allow me to help!
My first round of modifications used a smallish 12v Li pack through a 12v->9v step down converter. It worked (much higher top speed) but lacked the startup power needed for hills and his passenger. I suspected it was because the 12v pack was regulating output spikes to save itself (which, awesome).
Next step was to just remove the 12v->9v converter and let him run at 12v. Seems to be the popular voltage anyway. It would occasionally be everything he wanted but more often than not starting up put the battery in protect mode. Drats.
Enter, new, bigger 12v Li pack that can output 6a vs the 3a of the previous one. Issue is that the new slightly bigger pack doesn’t fit under the seat where the battery goes. No problem, dremel to the rescue:
Now instead of in the seat the battery sits lower, down at the bottom of the bike in this big empty cavern. It’s accessible through the chrome side panel via some screws, one of which I put back on, seemed plenty.
While I was poking around I needed to get the power wire backfed into this cavity and retain the fuse, so I went ahead and ran the charger through the same hole and now the plug to charge the battery is stored under the seat:
I tested with quite a bit of load on the motor (simply by applying friction to the drive wheel and tossing a 40lb bag of cement on the seat and hitting the gas and so far no drop outs. We’ll see if it goes that well when little dude arrives home. I am happy the weight of the battery (still less than the SLA one) is now lower in the bike as well.
Battery Pack used:
It’s an expensive item for this little experiment but I have a few things that it will be used for after this so it’s an OK investment for me.
UPDATE: Worked awesome, drove off road, through gravel and grass plus had plenty of power to go up hills etc.