Tag Archives: BATTERY

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.

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)

CHARGE CONTROLLER

#66 XH-M603 Battery Charge Module + Display

Charge controller board

The XH-M603 module is perfect for building a battery charging station, offering a range of protection features and easy to set min/max charging voltages. As soon as the desired battery float voltage is reached, the charging circuit is disconnected.

  • Input Voltage: DC 10-30V
  • Display Precision: 0.1V
  • Control Precision: 0.1V
  • Output Type: directly output
  • Voltage Tolerance: ±0.1V
  • Board Size: 82 x 58 x 18mm

Example of usage:

Plug into battery in order to power the pcb board.

Don’t connect the charge input yet…

Start charge setting (left button)

Press and hold the left button until the LCD starts flashing.

Now press to choose the desired voltage.

Leave the button until flashing stops and the chosen voltage will be set.

Stop charge setting (right button)

Press and hold the right button until the LCD starts flashing.

Now press to choose the desired voltage.

Leave the button until flashing stops and the chosen voltage will be set.

video example of usage