Introduction: Wired Table Lamp to Portable Emergency Lamp

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At our house we sometimes lose power when it rains and find it necessary to have some kind of light in the kitchen. This tutorial sows how we can convert a simple wired desk lamp into one that is battery powered and portable.

Supplies

You would need the following

  1. A working desk lamp
  2. DC -DC boost convertor module
  3. 18650 batteries or any battery that can output a decent voltage
  4. Battery holder
  5. Measuring caps

Step 1: Find the Operating Voltage

We first have to figure the input voltage for the LED, which simply means we can check in the circuit what its output voltage is. After opening the lamp back plate unscrew the circuit and find where the LED's wires are connected to the circuit. Using a multimeter measure the voltage at its output terminals. In my case it was 32 volts.

Step 2: Adjust the Output on the Boost Converter Module

Now that we have found out the required voltage, it is only a matter of setting the right output on the DC - DC boost converter module.

One thing you have to keep in mind is that the output voltage achievable on this module depends on the input voltage provided, for example if you provide 3.7v and expect 35v output it simply won't work. I found that it can boost roughly 3 times the input voltage so in order to get 32v I needed at least 11v and this was possible using 3 x 18650 batteries which gives about 3.7v x 3 = 11.1v.

Also note that boosting voltage means reducing he current output, in our case the LED had a current rating of 180ma which you can measure using the multimeter, I was able to get the required current at 32v so no issues for me here. But if you need more current then considering increasing the input voltage

Step 3: Connections

The connections are quite simple.

  1. Remove the connections from the existing circuitry
  2. Solder the LED wires to the output of the boost module
  3. Solder the Battery holder wires to the input of the boost module

My lamp has a switch that turns ON / OFF the unit, so I simply made use of that switch.

Step 4: Final Touches

I screwed the back plate and stuck the battery holder with double sided tape. Since the battery holder is bulging out of the unit, I had to think of some way to lift it up and found I had plenty of measuring cups which I used here.

A few things to note.

You can also add 3S BMS module and charge the batteries right here on the lamp itself, I chose to do it without the BMS as I had plenty of 18650 batteries and a dedicated 18650 battery charger.

The lamp running time depends on the charge capacity of the battery. I used 2000mah batteries and had a total run time of about 4 hours.

The lamp is well weighted due to the 18650 batteries and does not wobble around unless pushed.

Please post any questions if u need Info or help.

Thank you for your time.