JZK 6 PCS Boost module boost converter DC to DC 3.0-30 V to 5-35 V output voltage adjustable step-up circuit board, step up transformer power module

Good product, quick delivery.

It does not meet the specifications, It cannot convert 3.3v to 5v which should be easily within range, I tested all of them and the minimum output voltage wont go to 5

These do not meet the advertised spec in terms of current at all, they don't remotely reach 4A at the low end. Using a DC load and power supply as an input. The system required in excess of 3A input at 3.6V to produce 500mA at 5V output. Do not buy these!

Only tested one so far and destroyed a voltage regulator during testing. Probably not suitable for low voltage battery applications where the voltage might drop into the 3.5 v region due to an output voltage spike. For example - the device kept a very steady 8vo beween 3.75vi and 8vi before gradually climbing with the input voltage. At 3.6v input however there was a sudden spike up to 17v slowly dropping to 10v at 3.3v input. An output of 5.2vo was maintained between 3.6vi-5.2vi but at 3.4vi the output voltage was 12vo. If using a 3.7v lithium battery to power a 5v board this might be ok as long as the battery management unit has a precise cutoff at 3.7v. The output at 12vo was steady for 4.2vi-12vi, but there was a spike of 15vo at about 4vi.

For now I have used two of them to bring 5v. at 12 v. and they work.