Using Discarded Laptop Batteries To Power Lights

mrspoonsi sends news of an IBM study (PDF) which found that discarded laptop batteries could be used to power lights in areas where there's little or no electrical grid. Of the sample IBM tested, 70% of the used batteries were able to power an LED light for more than four hours every day throughout an entire year. The concept was trialed in the Indian city of Bangalore this year. The adapted power packs are expected to prove popular with street vendors, who are not on the electric grid, as well as poor families living in slums. The IBM team created what they called an UrJar — a device that uses lithium-ion cells from the old batteries to power low-energy DC devices, such as a light. The researchers are aiming to help the approximately 400 million people in India who are off grid.

Comments

Re:sorry, all my laptop batteries are dead

[mysidia]

If you're discarding laptop batteries while they can still hold a charge

You are likely to discard the battery as soon as it can no longer hold a satisfactory capacity for your application. The battery is no longer effective for your use at that point, and you're wasting electricity time and $$$ and not getting the portability you want.

Based on the IBM study:

Fig. 2 shows the charge capacity as a percentage of designed capacity for the investigated laptop battery packs. We found that although there was a significant variation in the residual capacities, the mean value was 64% while the median was 73%.

The mean value corresponds to more than 50 Wh of capacity for the batteries tested, which is sufficient to power a 3 W LED light bulb, a 6 W DC fan and a 3.5 W mobile phone charger simultaneously, for around 4 hours

Therefore, discarded laptop batteries appear to have satisfactory potential for reuse as backup energy sources to power low energy DC devices

40 watt PC battery vs. 3 watt LED

[billstewart]

Sure, your laptop battery may not hold enough charge to power your laptop any more, but an LED needs a lot less power than your laptop, depending on what it's being used for. Most of the lightbulb-replacement LED bulbs I've seen want 9-23 watts, but the flashlights are more like 3w, and nightlights are more like 0.5 watts.

Also, that laptop battery is a battery of cells, and they usually don't all die at once. They may not be in good enough shape to remanufacture into new laptop batteries, but still have enough of them good enough to disassemble at third-world labor costs to recover cells for off-grid LED lighting.