I, with - no, I am not going to tell - many years of experience would NEVER design a charger for modern batteries.

The risk of explosion with a just few percent overvoltage/overcurrent makes this something to ABSOLUTELY leave to the experts, NOT the "so called experts" many explosions or fires have been the result of 'aftermarket' chargers. And Arif, is an 'aftermarket' charger not exactly what you plan to make. When even the "so called experts" can't get it right, are you really goint to take the risk just to prove that you are better?.

There has been cases of using a charger for a different brand of the same type battey has led to explosion or fire. Not even Sony and Dell could get it right, they just recalled 4 Million notebooks because of a risk of explosion or fire in the battery.

I would advise especially you, against attempting to build a charger, if you are not able to spell the type of battry correctly. The Uniross STINKING website (it is one of those you can not back out of) do not list Mi-Hi.
Since the best I can do with the abbrevbiations (there are no chemicals abbreviated 'Mi' or 'Hi') I must guess it is a battery intended only for use in Michigan and Hawaii.

Erik