TP4056 board behavior - overdischarge problem

[MarkV13]

Hi,

I have built a small standard circuit as follows:

Li-Ion Battery -> TP4056 Charging Module -> MT3608 Step-Up Converter -> 12V LED strip (approximately 10cm)

Everything works as it should: the TP4056 charges the battery, the step-up converter generates 12V DC for the LED strip (works couple hours from full 4,2V battery). However, the problem arises when I discharge the battery to around 2.7V, and the system shuts down - which is supposed to happen as a safety feature of the DW01A in the TP4056. But the battery naturally recover to around 2.8V over time, and the LED strip turns back on. It discharge itself a bit again to 2.7V, and the cycle repeats. In short, it turns into a blinking Christmas tree (really slow one).

I would like to power a small portable lamp with this setup, but once it discharge, I don't want it to turn on again until I reconnect power to the TP4056.

My question to you is whether anyone has encountered this issue or has any tested alternatives?

 

[KlausST]

Hi,

Links to datasheets?
A sketch?

Klaus

 

[MarkV13]

It kinda looks like this:

 

[betwixt]

This is expected behavior, you are drawing more from the battery than can be put back in to it from the charger. There is a current limit set by a resistor on the charger module, the combined charging current of the battery and the boost converter is cutting the re-charge sooner than you want.

There is only one solution, to delay the boost converter operating until there is enough charge in the battery (extra circuit) but you cannot expect to run any boost converter through a current limiter successfully.

Brian.