LiPo g's and geometry considerations

[SolarYellow]

Thinking about how to package the battery and electronics in minimum-size, MD 24mm (and 18mm) rockets. There are long, skinny LiPos that could go alongside some of our smallest altimeters, etc. That's nice, because you don't have to assemble a choo-choo train of electronics plus battery (plus electronics plus battery...). Shorter body tubes are lighter and have less skin drag. But with dimensions like 60x11x6mm, for example, if you run the long dimension parallel to the airframe centerline and then accelerate it, what is the g tolerance of such a battery? Would it be better to just wire two or more of the thumbnail-sized 100 mAh cells in parallel and stack them flat, with the largest surface perpendicular to the airframe long axis so the hydraulic head pressure at the bottom of the stack is minimized? Or at least stack them like books side by side, minimizing the height?

 

[cerving]

I've used the skinny Airsoft battery packs in rockets, although not in rockets quite as small as 24mm. I've launched them to about Mach 1.8, they hold up just fine. I wouldn't be as concerned about the Lipo battery itself as anchoring all of your wiring and connections down... wires coming loose in flight is one of the primary causes of electronic deployment failures.

 

[rharshberger]

I use and have bays in 24mm and 29mm that house a Turnigy 2S 180mah LiPo, a Eggtimer Quark, and a Missleworks/Perfectflight screw switch. All are set up for single deploy streamer at apogee. The 29mm bay I recently uploaded photos of to the What did you do rocketwise today thread (having trouble uploading pics currently). Both bays are setup so the battery and switch are under the nose cone for easy access. The Blue Tube coupler is 8" long x 29mm.