if i wire up my GWS a-10 for multiple 2100 mh batteries, that will just increase run times right? is there anything other then weight and heat i need to do if i wire it this way?

if so please explain, im trying to learn as i go, and multiple searches on several different wordings do not work

It will also increase the total amount of amperage you can draw, or in other words, decrease the draw from each individual battery. This will give you the increased run times you've already mentioned, as well as keeping your batteries cooler.


A

is there any bad side effects from doing this?

Just the added weight of the extra battery.................

Its not worth doing as the 2,100 mAh batts will maintain the CG, add another pack and your wing loading is going to be high ... are you running on a brushless set up? If not then the stock motors will not be enough.