Yup, you can. You just have to make some nesting for it to allow you to hook up to the cells. You've also got to work out balancing so you can charge multiple cells at once.
However setting this up will be all on you as will covering all safety aspects. What worries me a bit is that if you are asking the question, it may be that you're not quite knowledgeable enough about it to know how to do this properly. That's not a dig at you at all so please don't take it the wrong way. I'm just being honest. I would also much rather you ask if not sure about anything like this.
I also fly RC planes and have a good hobby charger. I gave the same thing some thought before I bought my first 18650s. I ended up buying a
xtar WP2. I think it cost me about $20. My reasoning was that coupled with using a DMM it would do a very good job of charging my
batteries safely and I wouldn't have to drag out my hobby charger whenever I charged. The hobby charger setup would also include the wiring to hook up cells and an external balancing board which I had. Or I would have to wire it to use the internal balancing for the number of cells I would charge. It really seemed to be quite a messy way of doing this.
After about 1 1/2 years I'm still very happy with the Xtar. It's small, has only one adapter cable and works very well. All I need to decide when I charge is 0.5A or 1A. Works for me
