Hi - I have a pretty newbyish question - I'm working on a sig kadet senior electric conversion. My question is this: where is it best to have the batteries? I mean certainly they'll be in the front - but I'm worried about where they will be if you're looking down the airplane. I'll have two batteries. I'm going to assume it's best to keep the weight as low as possible? (well - this is how ground vehicles are designed - but I'm not sure about airplanes) But should the two batteries be placed in the center of the plane, or should I be placing them on the sides? Hopefully I'm being clear in what I'm asking. Thanks for your help!

I think i understand, I would put them in the center, but instead of facing them like this = face them like this ll if possible.. and also remember to velcro them.

So you're saying I should situate them vertically, side by side (as opposed to stacking them) in the bottom center of the plane, right? Also - how do you suggest velcroing them? Maybe have some velcro that goes between the two of them to keep them together, and then maybe some velcro on the bottom? Only problem is that they will be about a quarter of an inch above the bottom of the plane due to the frame (I was thinking I'd have them lying on the frame). Thus there won't be much of anywhere to stick them on the bottom... Any suggestions? Oh - I should metnion the fronts of the batteries will be up against the firewall, but I have not entirely decided how to hold the backs of them - I was thinking I'd probabaly put a fairly thick piece of balsa going across the backs of them with a piece of foam between the batteries and the balsa, but I'll have to figure out some way to do that so that the batteries can still be removed...

ok, let me rephrase...

I would put them side by side, where in the front if you need more wight to balance the CG, over the cg if you need no weight etc..

Velcroing them just is good, because if they come unhooked, then you are screwed and lose control. So velcroe just insures they don't come unhooked and keeps them from moving in high g manuevers.. (I have seen a cub go down because batteries weren't helod down, and they therefore unhooked from the reciever all during a loop and that loop went on for about 5 minutes...

Before you get too far along building things in permanent I recomend you do a trial CG balance test. Just dry fit, and tape on the tail feathers and place electronics, push rods etc. and motor with the prop, and everything close to where you think it should go. See where it balances. You don't have to worry about the little bits and covering yet, just the big stuff. Then if you need to move things around to get the CG right you will have a good idea what you need to do. The most important thing for a good flying plane is to have the CG right.

OK just to be sure (sorry I'm really new to airplanes), this is what you mean, right? Excuse the awful ascii drawing - I'm no artist The viewpoint is looking say through the bulkhead, as if it had been removed (I think that's what it's called)

Well - I'm quite sure that it's going to be tail heavy, as I have alot of electronics that will be placed in the back (camera and various other stuff), and also most people that have done an electric conversion on a sig kadet seem to have ended up with it being tail heavy... Also I haven't received alot of the electronics yet, which is unfortunate...

put them as far forward as possible long side paralell to the wing i will get a drawing on paint... give me 10 minutes. And put your receiever up there to if your still tail heavy. Probably gonna need weights..

ok here it is. hope you get what i am saying...

Oh - I see what you're saying. Problem is they're much too long to be put in that way. They absolutely have to go lenghtwise in the fuselage.

do as goboto described--get the thing finshed except for the batteries, esc, receiver, and other things that are easy to move around. Then, set them in there and see where they help the plane balance. You might have enough ballast just in the receiver and batteries to balance the plane without adding extra, dead weight. Also, this is a high wing plane, where lift is generated above the fuse. Vertical placement of the batteries will not matter at all--don't worry about the plane being "top heavy" like model cars and such.

PAY ATTENTION to what they are saying about the CG!!!!!! and your comment about knowing it will be tail heavy should be a clue that you are going to be in deep ***** trouble when you try to fly it. " A nose heavy airplane will probably fly but a tail heavy plane probably won't " BE CAREFULL !!!! Good Luck and ENJOY !!!!! RED

Put them Length wise in the tank compartment.. Probably best to drill several holes in your firewall and mount your reciever and ESC (mostly ESC0 up there along with the batts to keep everything nice and cool.. Plus it will help get some nose weight in there..

ok, its sort of up to you. the batteries defenately go in the center, but you can position them to the way you want.. so if u want this plane front heavy, put the batteries up front, vice versa for the back.