Vermes
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The charger works on three Li-Ion accumulators size 18650 about 2200mAh each, connected in parallel. Accumulators were removed from a laptop battery.
Converter DC/DC step up MAX1797 in a typical application from datasheet is responsible for production package 5V. Additionally, MAX works with protection against excessive discharge of accumulators, which is set to 3V.
When the voltage drops to about 3V, LBO output becomes active, and by SHDN input it disables the MAX. Maximum current of the converter is 1A.
Current taken from the accumulator while charging a phone is 1,14A for the charged batteries of the charger. MCP73861 with a current of charge set to 1A is responsible for charging the internal accumulators. The whole was closed in Z-97F housing.
Link to original thread – Ładowarka awaryjna dla urządzeń mobilnych