Tag Archives: LI-ION

IP5306 MH-CD42 HEARTBEAT

#108 Low current standby fix for IP5306 MH-CD42

BC547B NPN Transistor
IP5306 Module

Over the past few years I have been using the IP5306 chip and specifically the module shown in the image above.

The module is a great all in one solution for LiPo battery powered projects: charge, discharge, protection, 5v step up etc.

That being said there is 1 massively annoying caveat:

If the load current drops below 45mA during 32 seconds, the IP5306 will go into standby mode…

For low power battery operations this is simply unacceptable.. and I will not simply increase the current draw to keep it on.

There is an I2C version which allows us to change a few settings like standby mode in the IP5306 but for this fix I will focus on the “dumb version”.

Solution

An easy solution is to create a simple heartbeat circuit.

Since there is a button which will prevent the IC from going into standby mode, if pressed it will reset the *32 seconds 45mA* timer.

The module I have also has a solder pad where I can easily solder a wire to control this button via an MCU.

Using a *BC457 NPN* transistor we can create a simple switch to “press the button” at least once within the 32 seconds within a loop.

In this way we can constantly keep the module powered.

Parts

– NPN transistor (I used the BC547B)

– resistor (1k is fine)

– hookup wires

Connections

The Base connects to the resistor and then your MCU pin of choice.

Emitter gets connected to GND.

Collector gets solddered to the button pad.

Code

Once everything is soldered and double checked you can then add the code for the heartbeat.

In this case I use the millis() function and a simple repeating timer all written in a sketch .ino

WHY WE NEED AN EMERGENCY LED

#93 why we need an emergency LED tube

While load shedding continues to plague the average south African citizen I noticed that some of the well off citizens were not that phased out with the power going off and water running dry. Upon further investigation I found out that “big surprise” they had proper solar infrastructure and water tanks coupled with the right political connections they don’t need to suffer for decisions made by people who bear no consequence if that decision flops.

There’s nothing new about the facts I mentioned above however it got me thinking about looking for cheaper efficient and longer lasting solutions using technology even if they are not ideal its better to have something rather than nothing… what a shameful thing I had to say taking into consideration its the 21st century and governments are still using their governmental privilege to mess things up without facing a tar a feather spectacle such a shame..

Well unfortunately I can’t control things on a national scale but I can make a review of some affordable LED lights and hopefully that can help someone make a well educated effective decision to mitigate some of the frustrations and pain.

While browsing Takealot I noticed some prices fluctuate quite often but if you keep a price you are willing to pay in mind you can create a sort of mental filter that helps. So for this article I decided to search for LED lights containing these parameters:

  • Affordable
  • Rechargeable
  • Li-po or li-ion
  • LED light
  • 5v to charge
  • Have an enclosure
  • Easy access and battery replacement
  • Decent circuit with charge protection
  • LED’s must not get too hot

I managed to find a product that came as a value pack (the so called emergency LED tube) and passed all my requirements. The product came as a value 3 pack of generic LED lights each light is about 32cm long and very light with magnetic discs.

I got mine at R210.00 for 3 emergency LED tubes that’s R70.00 for 1 so definitely affordable since I can’t get any 18650 battery for under R100.00 anywhere I have searched online in South Africa. I might just purchase these lights and harvest the battery in future just because it’s cheaper than purchasing the li-ion battery by itself.

Transistors

The lights come with 1x unmarked 18650 battery and a charge controller chip with 1 button and a female micro USB port to allow charging via 5v

The button allows the light to function in 3 modes: bright, dim and strobe.

Even though the listing claims these lights are 18w when I tested them at a theoretical max of 4.2v (li-ion battery max) I only got around 10w and the LED strip got hot.

4.2v running at 10.4W though box claims 18w (LEDs super hot burns skin)
Mystery chip

A few cons I noticed are:

  • Solder wires soldered directly on to the 18650 battery
  • Cheap solder
  • Some joints were not soldered sturdily
  • Blue end caps can come off easily sometimes

All in all the lights did work out of the box however I touched up a few joints and glued one end of the blue cap just so it doesn’t come out when hanging the light via the plastic loop.

Once fully charged the light has lasted through 2-4 hours of loadshedding with a few hours of charge time.

Overall the light does its job and is affordable and the battery can be swapped or cascaded for longer lifetimes.

The only major concern I have it the lifespan of the LED chips and the mystery chip but only time will tell.

Blue wire was soldered to B+

Link to listing here.