Charger label says LiFePO4 battery charger model L100-48F, Input 100-240V ac, 50-60Hz, Output 58.4V, 1.5A, LED red charging green finished.
Label on the wheel itself says model sw-1, battery LiFePO4 (lithium ion), 2.4 Ah, 122 Wh.
i think the batteries are shot from likely being plugged in for several years straight, or from being unplugged for several years. Similar to a smart phone with a battery that’s going bad, you plug it in it charges super fast. You start to use it it sags immediately. In this case it maybe instantaneous charge/sag.
if the battery was more accessible I could just make up a Lipo pack that put out similar voltage and amps and had similar or greater capacity. 122Wh/ 2.4ah says 50.8V which at 3.7V per cell for lipo is 14s, which would be an awkward config but I could do it, likely with a mix of 4s and 3s.
But this isn’t swapping the lead acid 12V in a power wheel toy for a Lipo for grins, this one I’ll need it to be able to use the onboard plug and charger because I can’t just pop the pack out.