Solar Light from Ikea: SunnanBy Phillip Stearns
At Voltaic, we’re in the process of designing our own solar light and are constantly on the lookout for small scale solar lighting products that have made their way to market to see what we like and might do differently. We brought a Sunnan light home from the Brooklyn IKEA to have a look at what’s inside.
It’s a clever and simple take on the standard desktop gooseneck reading light with an eco-friendly twist. There is a solar panel and battery pack which are integrated into a single removable unit that detaches from the base of the lamp. This makes it fairly easy to place the panels in a good spot of sun for charging without them being obstructed by the rest of the lamp. It also saves you having to haul the whole lamp around to charge it up again. Plus there aren’t any cords or power supply inputs for “cheating”.
A look at the technical data:
- Light Source: single chip high output 4×4 element LED
- Battery: 3 x 1.2V 1200mAh NiMh (4.32Wh)
- Charge Time: 9-12 hours in full sunlight, greater than 12 hours when cloudy
- Operating Time: 3 hours of full intensity light
Don’t tell IKEA, but we actually opened up the battery pack to measure what was going on when placed in sunlight to charge. The current from the panel to the batteries reveals that only about 160mA is flowing when the panel is exposed to full sunlight. The voltage reads at about 3.45V which means just over half a watt is being generated by the panels. That 9-12 charge time is realistic, but it does prevent cells from over charging, which means they’ll last a lot longer without having to be replaced!
After leaving the battery pack on a window sill over the weekend, the light performed better than expected. Though noticeably dimmer after 4 hours, the light was bright enough to read by up to 6 hours later.
Things we like:
- straight forward design
- no-nonsense implementation of solar charging
- charge method ensures long cell life span
- cell power is well matched to the cells supplied
- inexpensive, only $19.00
Things we might do differently:
- Increase the amount of solar power generated. Our 2 watt small solar panel might be a bit too large, but we’d probably go up 50% or so.
- Increase the overall cell capacity. Simply doubling the cell capacity from 1200mAh to 2400mAh would double the time the light can be used. The cost trade-offs are minimal.