We were looking for a 3V to 7-8V DCDC Boost converter module recently and had a particularly hard time finding a suitable candidate. The current requirements were 0.6A continuous and 2.5A peak. Here are few of the options we considered.
All of these are marketed to work in an input voltage as low as 3V.
Here are some screencaptures of sales pages from Aliexpress sellers.
And here are screencaptures of resellers who are also marketing their wide input voltage range.
On bench testing using a power supply and discharger, we found that Option 1 and Option 2 did not meet the desired specifications.
Websites are falsely claiming their wide input range all the way down to 3V.
Option 1 – XL6009 based module goes into thermal runaway around 3.5V input, and is not able to maintain a steady 7.2V output at 400mA.
Option 2 – In the LM2577 based module, we found that the LCD starts to flicker around 4.9V input even at no load! This module definitely does not meet the marketed specifications of 3V input.
Out of the options we considered, we found that Option 3 was the best out of the lot. It does not go into thermal runaway even at 2.8V input, and operates decently well up to 3.4-3.5V input maintaining a 7.2V output at 500mA continuous. In our testing conditions, we did notice however that it the module gets considerably hot during operation, and with electrolytic caps on the board we don’t recommend running the board at high temperatures. We would recommend adding heat sinks to the LM2587 IC for proper heat dissipation and long term use.