Interesting, maybe the batch of coolcarts I got were not quite up to spec..
Either way, it takes a bit of experimentation. Drop in 20 first, spin, drop another 10, then another 5, until you find the sweet spot for the next carto.
With the KR808
batteries, I prefer the Premium Carto's. They take a bit less
juice, but seems to perform better, especially with Wow.