A few weeks after getting the yellow AA battery box done, my nephew got a power wheel car with no battery, so i figured i could come up with a battery based on my box.

i picked up two orders of these >>>> https://www.ebay.com/itm/80X-High-energy-1-2V-AA-Rechargeable-Ni-MH-Battery-Green-for-Lifhts-or-Toys/401434155033

80 1.2V batteries @ 3.3AH each,

and these >>> https://www.ebay.com/itm/Wholesale-Silver-Tone-Metal-Spring-Battery-Contact-Plate-Set-For-AAAAA-Batteries/382246713722

each tray takes 16 batteries, and 16 pairs of spring plates. so i printed 5 trays, 4 inter-battery pack spacers and one cover, wired all the batteries in each tray in parallel making each tray worth 2.4V @ 26.4Ah then i wired the 5 trays in series giving me a 12V @ 26.4Ah battery pack, needless to say the 6V little car, now really moves... lol. we had to take an old bike innertube and cut it open and pin nail the rubber to the plastic tires so it would get traction.

Assembly:

Ill give you an idea how to assemble it but you can figure out how you want it wired.

Print :
1 Back Cover
1 Front Cover
3 wire layers
5 Battery Boxes.
roughly 700g

1.I started by putting all the spring plates in the little slots its a very loose fit on these but at the time i was waiting on hong kong post so i could get measurements

1. once the plates are in install the batteries to hold the plates in place

2. then using 2 3MM screws install the wire layer over the tray,
   4.turn over and make solder connections. Yes i know these are batteries, and if you didnt know that well we are working with batteries yall, so you have exactly 2 seconds to make your solder connection or you die in a massive fire...just playing, batteries normally get spot welded, im not saying stuff doesnt happen but if you use your grey squish you should be ok. after all your connections are made remove the wire layer cover that you places on to hold the batteries in with,
   5.repeat steps 1 to 4 four more times

3. this next part is tricky for the hardware impaired . the 6 tabs on the sides of the trays are for all tread rod, or threaded rod or whatever you wanna call it, i use it in nearly all my designs becasue i have about 100lbs of the stuff, it basically makes giant bolts. get 6 pieces of all thread that are the height of your battery stack.
4. thread one nut on to the very end of each rod
5. place one washer on to every rod
6. thread all 6 rods into the holes on the back cover and lay the flat side of the cover, with the nuts and washers facing down,
   10 the back cover has indented recesses so your leads can come through, thread all 6 rods into the first tray and slide it doen the rods, pulling your wires through and into the recesses, keep in mind if you still have the batteries in, the wires are live. (and somewhere around 10Ah to 30Ah amps of power are present depending on your battery selection)
7. on top of that tray place a wire divide/recess, this performs 2 functions it lets the wires from the tray above it escape, and it hold the batteries in place on the tray below it
   12 repeat steps 10 and 11 until al you have left is the lid...
8. run the rods through the lid
9. install washers on all rods
   15 install nuts to all rods, and snug into place,
   16, with a grinder or dremel, depending on your skill level take off the excess rod
   17 torque top nuts to 75in/lb,in a 6 way star pattern this will pull any and all slack that may occur from printing errors and makes the battery pack very solid,
   18, all your leads that come from holes use heat shrink and solder and connect accordingly...
10. terminate battery leads
11. plug in and go...

a little more story time.... so then my nephew is on this car and we put it on face book and a friend of a friends dad get ahold of me and asks just how big i can make them, my literal response was, how much do you want to spend... so he commissions me to make a 400Ah battery pack... 1200 AA cells. massive. i changed the design though so that design is for another thing :)

-T