Tag Archives: LITHIUM 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

JIAGENG MINI UPS

#94 another mini ups review

Nice honest stats compared to others.

Looking at other mini ups manufactures I decided to give Jiageng a go. The outer plastic enclosure looks very similar to a lot of other generic mini ups devices. I suspect they all originate from the same factory but have slight improvment’s to the actual PCB inside.

Decent PCB with good amperage Inductors.

Once opened I was greeted with a beautifully soldered matt black PCB with a higher version number than the previous mini ups from Andowl.

The PCB has quality components and no mystery chips. It also has the iconic Wintonic 18650 cells.

2 differences I noticed are that all the LEDs are a dark green color (the Andowl unit had 2 different greens) and the unit powers off automatically at a low voltage so that it doesn’t require a reboot after it runs “flat”.

The unit also has flashing LEDs as apposed to the Andowl’s fading LEDs

Top
Back
SKE-POE430-V3.0 matt black
Main IC is the STC8H1K08

Datasheet can be found here.
Andowl artical can be found here.

SIMPLE DIY 18650 BACKUP

#87 A DIY simple 18650 backup ups board

After setting up a CCTV system consisting of multiple WiFi cameras placed over my property I noticed that certain cameras were located in areas far away from AC outlets covered by my backup electrical system.

In this project I used some an old 18650 (LG makes the LGABD11865 ) from a laptop power supply. Also I upgraded my 5v charger to a 1.5A to provide enough charging and running current for the camera. The camera I am using is the EZVIZ C3W 1080p WiFi camera

Since Load-shedding has been increasing dramatically I had the need to find cheap simple and reliable power sources for there cameras (12v DC). One important requirement is that the backup system needs to fit into a small area E.G an electrical box on a pole where the camera is located.

While researching I came across the so called mini dc ups device mainly used for backing up WiFi routers at either 9v, 12v, 15v, 24v. however these devices seemed a bit overkill electronically wise and also price wise.

So I decided to opt-in on a cheaper smaller sized DIY version the components consisting of:

  • LiPo charger +DC-DC step-up module here
  • suitable PCB board here
  • 18650 li-ion battery holder here
  • 18650 battery 3500mah here
  • 5v cellphone charger micro-usb here

The components are all soldered onto a 50mm x 70mm 1 sided PCB board.

I noticed that the 4056 IC gets quite warm but doesn’t burn my fingers. The same goes for the coil. The specification is max 1A and the load I was applying was around 0.33mA – 0.670mA

After testing this particular LiPo charger PCB I noticed a few major problems the first being that the 8-pin 4056 LiPo chip is a copy of a copy… the next critical problem is that there is no protection circuitry besides the overcharge/discharge function in the 4056 chip.

This is a big problem since the chip does not switch off completely when low voltage occurs and as a result the load will periodically switch on and off unreliably before finally switching off completely. This oscillation can damage the load.

A solution will be to use a separate LiPo PCB with protection mosfets and a separate booster board.

A better solution
4056H PCB + protection mosfets and DW01-A
B6289Y (MT3608 booster)

GENERIC MINI UPS

#86 Generic min ups 8800mah

12000mAh claim or is it just the name? Only a lawyer could legally advise.

When looking for a suitable min ups for my CCTV cameras and WiFi router I found a wide selection on takealot. After doing some research I noticed that the Q-UP1000 mini ups was listed by many vendors but at varying prices. Many companies had rebranded the device and increased their price quite dramatically.

Wintonic INR18650 3.7v 8.14Wh which is = to 2.200mAh

Finally I came across a deal selling the device for under R500.00 and I purchased 2 Andowl devices. Once I received the devices I was impressed with the quality of cables and the plastic mold of the box. (There are no screws to unscrew the box simply pops open)

No Screws needed to open the box. Four 2.200mAh INR18650’s for easy replaceing

Once the box was open I noticed a decent PCB with all the necessary protection circuits. There are two mystery chips though.

Mains charging circuit

The product was made recently (at least at the time of writing this article) and the designers made the batteries easily accessible for swaps which is awesome.

Charge controller IC

Now a negative thing I noticed is the 12000mAh claim… clearly the batteries are four 2.200mAh INR18650’s and this adds to 8.800mAh

There can be many reasons for this capacity “lie” but other than that the mini ups is looking good. Time will tell if this was a decent investment.

Back
Front

See manual pictures below: