oh kgo battery

so i had my new kgo battery with me the other day-I just bought this one to replace the one that quit working after 2 months-and the darn thing was sticking on! I was pretty concerned-had to keep unscrewing the carto-but i popped off the rubber button and cleaned it and blew into the hole where it was-working now, but I don't know if juice got on the button (didn't think so) or what. I like the button on the ego t passthrough better-its a hard plastic. Also, for some reason my older kgo batt (2 months old) that is still working, doesn't thread onto the charger good-the new one does. I cleaned off the threads etc., so I don't know what the prob is, I can get it on there still, but have to do it very carefully.