whats the limit on batt cells?

thanks ,btw 15c discharge is not bad??i was lookin at that charger is it good?how long will it take for that charger to charge the 2s 5000mah ?and u said theyre actually 20c?would that be a problem in charging them?and can u change the connectors to deans?just wanna make sure does that charger have balancer too?thanks!