As far as the higher mah battery, that is no problem with regards to your other electronics. Changing the voltage is another issue altogether. Two things consider when going to a larger mah battery. 1st, will it physically fit in your helicopter? 2nd, will the added weight be too much for the heli to handle? Going from a 1200 to a 3000 is a considerable increase so just check and confirm the above otherwise you will be fine. You may want to consider a something in between 1200 and 3000 as well. As far as a balancing charger it is always good to balance charge your lipos. Starting out, I would suggest you shop around for an inexpensive one (there are some out there) that will charge a 2s pack and move up to a better charger later. I have a couple of inexpensive Esky chargers that work fine for the smaller heli's.