Power Brick

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Power Brick

For usb and misc electronics. Charges via solar panels.

inside

diagram

sorry for the handwriting.

Fuses keep circutry safe. Diode keeps the batteries from discharging into the Buck Converter and solar panels. Battery Managment System (BMS) keeps the LiIon batteries happy.

Made from

- 18650 LiIon batteries recyled from a drill battery - 3 LM2596S adjustable buck converters - 2 amp fuse - 20 amp fuse - switch - brass hardware (screws and stuff) for conecting to the batteries - this was like $20 >:( - springs for the brass - 1/4 inch ply-wood - wood scraps - toothpicks (as dowels)

links videos that helped make this thing

The switch is needed because LiIon batteries cannot be charged and discharged at the same time. Phones and the like run off of the charging cable while the LiIon battery charges. Can a lithium battery be charged and discharged at the same time？ --Utsource This is the dc to dc buck converter that was used. Can also limit the current allowed through. TUTORIAL: About & How to use a Cheap LM2596S Buck Converter / Battery Charger Module - Arduino LM2596 Constant Voltage / Constant Current Module! Shows how the circutry of the BMS works. Exploring A CHEAP 3-cell BMS Board! How to Use a 4s 40A BMS Module to build Battery Packs?

thoughts

- There would need to be two of them or somthing for it to be useful. One for use. One for charging. - The solar charging with these small panels very slow, it seams. - Used it with a portable projector after 3 days of charge. Gave about 2 hours of projection? - Being able to remove batteries means they could be put in backwards and stuff. Scary :| - Could also lead to large amounts of fast discarge from neighbor batteries. - LiIon can catch fire. This box of power scares me please contact us if you want more detail on somthing for instance, we've lost all the pictures of the making of the box.