Not worth the hassle even if you could do it. You have to have a charger that can charge Li-ion for one and it has to be the exact charger for the brand you are using. The makita LXT chargers have built in sensors and chips to keep track of temps and amount of uses so that they can be checked on computer if they are faulty. I would wait until you start to see more LI-PO type tools and then start to upgrade your kit.