Uninterrupted Power Supply and Capacitor

I found this module, and it needs 5V power supply when it simultaneously charges batteries with integrated battery protection circuit and gives output of 5V. When power supply is cut, it switches to use the batteries to supply 5V output. There is an interruption of about 0.3sec when switching. At this stage, the module switches off if load is less than 50mA.

I try to get rid of the interruption by using a 1.5F 5.5V capacitor parallel to load but did not get the result I hoped for. Now when power is cut, module switches off temporarily, when power from cap is being drained to a certain extent. Only then, it will come on, but even then, it will repeatedly switch on and off quickly. Please help me understand what is happening.

This is the link to the module:

The diagram is little sketch of my work.

Maybe I need to add a diode?

OP's image:

This might help, the PCB has a trigger input that may be causing an issue, also a low current output shutdown.

Tom... :slight_smile:

What you are saying appears to be correct. Your module shuts off when the cap is connected because it has a no load shut off, which is activated when the capacitor is supplying the current to the load. I think the switch over delay is because you are on the light side of the modules current rating. I assume you used a scope or logic analyzer to measure the 300ms delay and not hmmm that is 0,3 seconds. Try adding a little more load such as a LED and measure the time and see what it does, it will probably get much shorter. Also check the output voltage it man not be dropping very much,
Good Luck and Have Fun!

I have experimented with different loads, and even though it says the maximum output is 2A @5V, LEDs start to dim when I add more than 10 in parallel. The charging current is only 0.15A and it dropped to 0.11A when I connected 220ohm and white LED to output. Nevertheless, whenever I connected the capacitor in parallel, said thing happen, irrespective of load.