Solar Lamp Hack to run off wall power!

This Ikea Solar Lamp, that I bought at Ikea, has a solar pack that charges batteries to power the 16 LEDs inside. This is very bright, but what if the batteries died and there is no sun because it is cloudy outside or for some other reason? Well now you can plug it in and it will run off the main supply! This is the first Ikea Solar Lamp hack to run off wall power.
IF YOU RUIN THE LAMP, IT IS NOT MY FAULT. THIS IS AN EDUCATIONAL HOW-TO PROJECT FOR THE SAKE OF THE LAMP.

Step 1 Materials...

You need:

Ikea Solar Table Lamp ( I bought at Ikea)

5v Small Transformer (was a cell phone charger...)

22 Ω Resistor ( RED   RED  BLACK ) It is okay to use this resistor. It won't ruin anything.

Diode (found in common electronics! 1 amp diode will do!)


Tools:

Soldering gun
Solder

wire

Philips screwdriver

Drill (to make hole for wire to come out to transformer)

Helping Hands 

Wire stripper

Comments

[aterz]

Thanks, very interesting!
Is it possibile to have a simple schematic of the circuit? As far as I understand the charger is directly linked with the leds using the 22ohm resistor to keep the current low and the battery has the diode in series with the + pole in order to avoid the current of the charger to enter the battery. Is it correct? At the end the diode reduces by 0,7volts the Voltage to the leds thus reducing the luminosity, is that right? Thanks for the answer.
It would be interesting also to open the solar panel and the battery in order to have also the battery recharged when the charger is plugged in...

[alpe_97]

Hello! Yes that is correct. (I had to read it a couple of times though... haha)
It might be hard to draw a schematic of the insides of the battery pack because there is ICs in there.

Find the positive wire coming from the little circuit board that connects to the connector plate (that is what connects the lamp's LED and switch.)

Now just un-solder the positive wire, coming from the little circuit board, FROM the connector plate, which goes to the lamps switch and LED array, and insert a diode with the stripe closest to the connector plate(so the stripe is also farthest from the circuit board.


Then on the connector plate on the Lamp. Find the positive and solder on the resistor then the wall adapter to the resistor.

If you need more help, just ask! ;)

[aterz]

Hi,
I did it. I saw that leds adsorb any current you push into with maximum 2vols fall. I eden tried to connect 12v power and I saw corrent up to 0.8amp! They were fine.
So ok diod, resistence at 40ohm, power supply 5volts, current around 50-70mA so only 0.25watts consumption half of which falls on the resistence that so has it is enough a 1/4watt normal resistence.
Next step is to put a potenziometer... From 10 to' 100 ohms
Ciao
Andrea

[etanol]

Nice! I actually do something very similar but with an old phone charger and Ikea solar lamp, but without resistor and diode.

Use it when the battery is low and just leave the solar battery pack in so it powers the lamp and charges the batteries at the same time. The charger does not seem to mind, it does not get too hot either. As the batteries could get damaged when overcharged it is not wise to charge them for too long though.

[pacwoods]

Why not just replace the rechargeable batteries?

[Almondsbury Puffer]

Did something very similar for my Dad's solar garden light array.

We actually removed the solar panel and charger (as it failed after around 5 years of continuous use).

We used a old phone charger and ran it direct to the LED lamps. There was enough electronics in the lamps to regulate the current (as the lamps gradually change in colour).

Great use of old phone chargers - which we all have cupboards full of!