I did actually (contrary to MR. RC guy above me here). Sorry to hear that FPV wasn't your thing. Regardless of how you got the batteries, the thought to me would be to get the car first then get batteries that fit the car not get batteries first and then get a car to fit those batteries. As for your question, it really depends on the size and shape of the batteries. Now knowing that they are 3 and 4S tells me they are probably pretty sizeable batteries even for smaller applications. Also, think about where you were looking to zip around. If you are looking at offroad, there are probably quite a few choices from folks like Traxxas, Redcat, and others. Onroad is going to be a bit more challenging...then once you get your car, you have to consider will your battery fit in the battery tray. If we are talking mini/micro-size 3/4S batteries, then you are looking at something like the MIni-Z, TLR Mini-T, and others of that class. There was a lot of information missing from your post at the top of this discussion that would better inform readers of this thread so they can point you in the right direction (even though you are going about it a tad backwards as I said before)