4 X AA Switched Battery Box

thingiverse

4 X AA Switched Battery Box This is a remix of... Parametric Spring Contacts Battery Box for AA Cells https://www.thingiverse.com/thing:1755397 by ffleurey, posted September 05, 2016 I really like the original design. The purchased spring contacts are fairly cheap in quantity, easy to use and fit perfectly into the OP's model. They are a great way to make a professional and functional battery holder. The wiring channels in the back make everything compact and easy to wire. I've modified the 4 X AA file adding a switch, a cover and an optional rear cover. I did a similar remix to the 3-cell version of this model in September, 2022. It's here... https://www.thingiverse.com/thing:5508277 In this model, as with the 3-cell remix, I flipped every other battery around from the OP's orientation, providing a more conventional "nose to tail" layout of the batteries. This also shortens the internal jumper paths and eliminates a couple of crossovers where the jumpers would have to cross the center wire channel in the original layout. Electrically, it's still the same - four cells in series providing a nominal 6 Volts. The original external mounting lugs are eliminated. Instead there are a pair of countersunk holes sized for M2.5 flat head screws in the bottom of a couple of the battery trays. They don't interfere with the cells. The top cover is secured with an M3 X 16 mm Allen head cap screw engaging an M3 X 5 mm threaded brass insert pressed into the case from the bottom. The hole is shouldered so the insert cannot pull through. The pocket in the cover where the screw head fits is sized to accept an M3 flat washer under the screw head. There's a little clearance (~ 0.5 mm) between the screw posts in cover and case so a small paper or acetate disk can be used as a screw retainer to keep the screw captive in the cover. In the 3-cell version, I had the switch in the negative lead. That's changed for this model and the switch is in the positive end of the battery stack. The bottom/back/rear cover is optional. When assembled, the contacts and solder joints protrude slightly from the rear of the box. The back cover is intended to be glued in place after the wiring is done. It provides a flat back surface and protects against accidental shorting of the connections, at the cost of adding about 1.5 mm to the overall height of the box. If used, there are holes for the mounting screws to pass through the back cover. The top cover file includes semi-circular hold-down tabs 0.2 mm high to help prevent the corners lifting from the bed while printing. Those are easily removed after printing with a hobby knife. All external corners and edges are radiused. Switch: https://a.co/d/3sVIYnA Switch Screws: M2.5 X 6 mm flat head wood screw (holes in switch posts are sized for these) Battery Contacts: https://a.co/d/8JTwsrs Threaded Insert: https://a.co/d/fiNKmpN Printed in PLA without supports; 1 mm shell; 12% infill; 0.3 mm nozzle; 0.2 mm first layer; 0.15 mm layer height If desired, the wires can be secured in the channels at the bends and where exiting the case with UV cure glue or cyanoacrylate. Use 26 gauge solid wire for the intercell jumpers (white in images); 26 gauge stranded for the output and switch wire (red and black in images).