3-Amp Car Battery Charger, 6V and 12V Smart Fully Automatic Battery Charger Maintainer, Trickle Charger, Battery Desulfator for Car,Motorcycle, Boat..Lead Acid Lithium LiFePO4 Batteries

First thing I do is get rid of the propietrary plugs for the battery and crimp on spade connections. Use your Milwaukee batteries to test if it even works. If all works I'd get a 12v 12ah SLA from Amazon for 27$ https://a.co/d/0fDK7WuM and a 12v 3amp charger for 25$ https://a.co/d/0ad6hhKX And just let It be a good consist ride on that they get used to using before jumping any voltage. You can also add your own LED lights and radio and basically any other 12v accessory you can think of. This looks like you're ride on https://www.bestbuy.com/product/winado-12v-kids-ride-on-car-toys-licensed-porsche-cayenne-powered-electric-car-for-kids-with-parent-remote-control-led-light-white/J25L37RK5V/sku/11949892?ref=212&loc=Marketplace_22974659265&gclsrc=aw.ds&gad_source=1&gad_campaignid=22980885536&gclid=Cj0KCQjwzqXQBhD2ARIsAKrIeU8xdXlTbgchuerWUXRrKWxjIMgVT5i14bSiE8gh01614vPSID3K8KUaAiZAEALw_wcB