A tutorial/log on how to make an extended battery pack for htc vive trackers.
- 5-7 Additional hour battery life for a total of 8-10 hours
- relatively small form factor
- no external wires
- charging via 1 port
- MT 3608 Boost Converter (“2A” version)
- TP 4056 Battery Module with Battery protections
- 7 *M2x10mm (self tapping screws/ flat heads) 4mm head
- 1/4” mounting screw 10mm shaft
- Switch (5mm knob CYT1107)
- Stranded Copper Wire 22 gauge
- Solid copper Wire 18-24 gauge (I use unshielded craft wire)
- 504050 Li-poly battery (ideally w/ battery protection circuit, and ~1500 maH capacity)
- ~25 Gram Filament (I use PLA, though higher temp plastics might be easier to work with) ?s=200` at the end of the image URL.
- Various Screw Drivers
- Large flat-head for tripod screw
- small for m2 screws (dependent on what you buy)
- very-small flat-head for adjusting potentiometer on MT 3608 board.
- Soldering Iron w/ solder (and comfortable w/ working on ~ 3 mm pads)
- small needle nose pliers
- wire cutter
- wire strippers
- Basic Multimeter/Voltmeter
- 5v Power supply ending in Micro USB (i.e. usb port) [ideally 1A plus]
- Drill w/ 1/16" and 5/64" bit
- SuperGlue or Hot Glue
- current clamp
- USB voltmeter/ammeter etc. (something like "AT34")
- helping hands, and other soldering assistant tools
- sand paper or other for extra plastic removal
- heat-shrink tubing
- mounting options ( I use elastic for feet and a belt for waist )
- kapton tape
- misc tape
-
Print off all Three Parts of the Tracker.
-
Take the top of the tracker and using the 1/16" drill bit drill out a hole for pins 2 and 3, near top or Bottom of the "slot"
- Solder some of the stranded wire to a piece of plain copper wire, then feed the piece through the holes made.
- Make a Hook with the needle nose pliers, and then using soldering iron "melt" the hook into the tracker base to allow the wire to be secured to the top.
- The hook should rise ~1mm above the lips in the model seperating the pad.
- At this point it is HIGHLY recommended to place the tracker on the front, and attach a 5v power supply to the pins to ensure that the electrical connection is good with the pogo pads.
- Now we will mount the two circuit boards, Holding or attaching the mid piece to the top piece you can arrange and fix the pcbs to the top
- Now Assemble the remaining wires per the diagram, But leave the battery for last, and you may want to Test before adding the battery.
- you can use shrink wrap tubing here to make a somewhat sturdier platform
- Adjust the boost converter, Hook it up to a power supply, and test the output voltage with a voltmeter.
- the potentiometer can be adjusted by slowly rotating the knob, your goal is 5V output per spec the tracker should be able to handle +- 5% so I typically aim for 5.05v or so to handle some voltage drop at load.
- (optional) Test Tracker, moutning it, and watching a current draw from a USB power meter or similiar.
- you will see a low current draw at the start, and then after 5-10 seconds it should jump to a max of ~500 mA (The amount of draw will depend on charge state of tracker)
-
Attach battery, it is a friction fit into the bottom part of the tracker, do not force it overly.
- you may need to sand down your bottom part slightly to let the battery fit.
- you may want to kapton tape down the wires from the battery to prevent them from getting snapped in the side.
-
(optional) test battery, see that it charges from wall decently, switch should be off for wires to boost converter.
-
pre-drill holes for screws 3 on top and 4 on bottom, though there is no real golden rule here.
- Caution you do not want to puncture the battery and have very little wiggle room
- use the 1/16" to drill ~75% of the entire length
- use the 5/64 to drill most of the first layer.
-
Assemble Top half
- using super glue or hot glue position the switch correctly, and then screw the top two parts together.
- Attach Tracker
- using tripod screw, attach the tracker to the battery pack
-
Assemble Bottom
- Carefully Screw in bottom screws.
- Additional pictures in the "Pics" folder
- STL/OBJ files in the models folder