Well I don't have the voltage set full high or low i leave it where I was using it last, could that be part of it? My wife's charges in like 2-3 hours bug she has a 400.
The specs you gave fit the charger specs for Ego style batteries, not sure why it took so long to charge. I do have the 1300 mah Spinner and a kgo charger. For some reason every so often I have to pry up on the center post of the Spinner to get it to charge correctly, I also do the same to the center post of the charger.
I have read on a couple of vendors sites to set the Spinner to 4.2 volts when charging, I normally turn the Spinner off before charging also. I don't know if any of those make a difference as I don't always do that and have had success charging.
As for the center pin, use something small and solid, tweezers seem to work for some, I have even used a paperclip. Anyway in the center of the connection where you screw on the delivery system is a pin, for lack of a better word. Take the tweezers, and gently pry up on the pin, working your way around the entire pin, do this a few times, GENTLY, you just want to raise the pin slightly,not pull it out.
For some reason these pins tend to get pushed down, over tightening the delivery system is the main cause, but some toppers just seem to do it without being cranked down. When it gets pushed down, the pin does not make contact correctly or at all. Sometimes it won't fire the topper, with mine the darn cheap charger doesn't work right. I do the same thing to the charger, and voila, the Spinners charges completely and quickly.
I would honestly recommend not doing this to the charger unless you have no choice, make sure the Spinner is off before doing this, and if you do this to the charger, make sure it is unplugged, other wise you may get jolted.
In my case I think it is the cheap Kgo charger, everything else works without a problem on the Spinner and I careful not to over tighten anything.