MLToys 18-20v Lithium Soft Start Low Voltage Module v 3.0 - Use Power Tool Batteries in Power Wheels

This kit will allow you to use 18 or 20v lithium power tool batteries in your Peg Perego, Kid Trax, or Power Wheels brand 12 volt ride-on.
Buy it here: grade-batteries/products/18-20v-lithium-soft-start-low-voltage-module-v-3-0
It solves 2 of the big problems that people encounter when trying to just wire a lithium battery directly in:
1. The module has a low-voltage cutoff that many tool batteries do not have one. If you over-discharge a lithium battery it won't charge again and may catch fire. With this module the LED lights up and an alarm sounding at 15.5 volts. When the voltage drops below 15 volts for 60 seconds the power will shut off. Make sure this voltage minimum is within your battery manufacturer's guidelines.
2. The initial "punch" that a lithium battery sends through the motors, gears, and switches normally destroys them. The module has a "soft-start" that gradually applies power to the wheels over a few seconds if it senses there is too much amperage surge. A regular voltage reducer will not stop the initial punch and limits top speed. You'll still have the same top speed with this module. The wheels will still be able to spin on pavement too. In high traction areas the module will be limiting that initial amperage surge which does all of the damage. That's where you'll see reduced wheel spin.