You want to control the charging of battery with the help of uC an thyristor or you want to control the charger itself? And if so, what do you mean by that?
Yes you can control the charging of battery by controlling the current it is taking. That is called trickle charging if you are controlling the current by tenth of the order of its AH rating.
For that you need to know the current you want to inject and then supply the pulses based on the current requirement.