+ easier to use

Field trials showed that some users were unable to lift the bag to its full height. In response to this, the way the bag is lifted has been completely redesigned. We have incorporated a pulley system so users of any height or strength can lift the bag right up to the top - giving the maximum drop time.

Use of GL02 does not depend on a person's strength or their height

This not only makes the product more accessible, but also offers a key benefit over GL01: instead of the light going out when the product is recharged by a bag lift, the light from GL02 stays on even when the bag is being lifted. This means GL02 can give continuous light throughout the evening.

GL01 - Light goes out when recharging

GL02 - Light stays on even when charging (as long as the bag doesn't touch the ground)

+ brighter

Surface mount technology has brought LED lamp efficiency a long way, and continues to do so. GL01 employed a traditional through-hole LED lamp which offered very well defined characteristics, stability and reliability, but not the most efficient light output.

We've been exploring a range of surface mount LED lamp options to identify candidates that pair most effectively with the GL02 generator. As a result, the new lamp is around twice as energy efficient.

In addition, with GL01, users had the option of a 'High', 'Medium' or 'Low' power setting. It was found that most would opt for maximum power and rarely change it. So GL02 has one power setting, brighter than GL01's short duration 'High' setting, but running for over 1.5 times the duration: over 20 minutes per lift.

+ more robust

It's important that the drive system is protected should an extremely heavy load be applied - we found that children really enjoyed swinging on the GravityLight bag!

GL01 had a protection mechanism that clearly indicated an overload with a red light, and helped reduce damage to the gear teeth by allowing it to run more swiftly, but this did not make it indestructible. An entirely novel way of protecting the system has been designed for GL02. It will allow an overloaded bag to descend to the ground in a safe and controlled manner, repeatedly.

GL02 suspends the bag from a pulley, which reduces the strain on the cord and the gearing. This also decreases the loading on the drive system and permits a smaller gearbox ratio, which helps to improve efficiency.

+ longer lasting

After several hundred hours of using GL01, some users noted that the light output would start to diminish. Some parts in the gear box were wearing out prematurely.

We carried out an extensive series of product life testing. We experimented with different materials, gear geometries and arrangements and now have a design which will go the distance!