Published: August 5, 2016
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By: Thomas Elemy, Cal Poly Pomona
Hashtags: #Circuits #Electronics #Engineering #howisudy #lithiumpower #Optimization #Presentation #Technology
Convert a camera to use rechargeable batteries. I purchased this camera on Ebay for about 15 dollars and it was powered by AA batteries. That would normally be fine but the batteries last only an hour. Say you want to place your camera in stationary position to take a timelapse or film, every hour you would have to change the batteries. Without the ability to charge the camera, changing the batteries every couple of hours would ruin shots and be impractical.
-Tp4056 Li-on charger
-3.7v to 5v Dc-Dc converter
lithium-ion rechargeable battery
Looking at the camera we notice it is powered by four AA batteries wired up in series. 1.5v x 4 equals 6v so we can asumme we can power this with 5v because as we use the batteries the voltage will sag. The total capacity of a AA alkaline battery is around 2,500mah and this will be our total capacity of all batteries since they are wired in series not parallel. The two Li-on cells that I chose to use have a capacity of 2,220mah in parallel so our run time for the camera will be slightly less than with the primary cell version.
The hardest part was finding the traces on the board for the positive and negative input. disassembly of the camera was rather difficult without completely destroying the camera.
One thing i would like to add is a voltage monitor for the Li-on battery. Even though the Tp4056 has builtin low-voltage protection, since the dc-dc converter always outputs 5v regardless of input voltage between 5v to 3v, the cameras built in voltage monitor has no way of showing on the display of when the batteries voltage is low.