Looks good. I did the same thing with my battery....works well. People keep saying I should buy the saddle packs for the front axle, but I have 5 brand new 4200 stick packs. I will be leaving it under the battery plate for now 
Yeah same here, I bought this thing as a cheap hobby so I would only have to dump small amounts of money into it from time to time, I had several stick batteries already from my earlier RC days and I figured this would be the best bang for my buck.
