The Ansmann Solar/USB Charger has three suggested operating modes:

• Charging the two internal AA NiMH batteries from the built-in solar panel
• Charging the two internal AA NiMH batteries from external USB power, e.g. your computer
• Providing emergency power to a mobile phone or MP3 player

When charging the batteries, the solar panel applies 20mA - 100mA (max) subject to availability of sufficient sun light. This makes for a charge time of over 14 hours for the included 1300mAh batteries from empty. When you plug the charger into your computer, it draws up to 200mA, reducing the charge time by half or more. Once charged, you can use the AA batteries in any compatible device. Because the batteries use NiMH technology, the expected usage pattern of frequent partial charging and discharging is absolutely fine.

The charger base features an enclosed compartment for the two AA batteries, and it will work only with exactly two AA NiMH batteries. The charger casing also functions as a flip-out stand to help you adjust the solar panel to face into the sun as directly as possible. Both a strap and a belt clip are provided to enhance portability. The solar charger works best when you give it as much exposure to sun as possible, whether you're stationary or moving about. The charger doesn't have any exposed electronics, but it is not designed for serious exposure to water - none of the sockets, switches or battery compartment covers are water-proofed.

Emergency backup power is provided by the batteries. The charger has a little switch labelled "in" and "out", to select the operating mode. "In" means power into the batteries, either from the solar panel or the USB lead. "Out" sends battery power to the power lead, which has plug adapters for the most common phones by Nokia, Motorola, Sony/Ericsson and Samsung.

In addition to the three suggested operating modes described in the instructions, we have found that in the "out" setting, and without any installed batteries, the power generated by the solar panel is sent to the power lead. But this is of limited practical use, because the voltage and current fluctuate significantly with variations in lighting conditions. You can't really power anything directly from the solar panel, which is why the unit is really a cleverly designed power storage facility: store power in the AA NiMH batteries while sun permits, and provide it when needed.

• Charger base with belt clip and carrying strap
• 2 x AA NiMH 1300mAh batteries
• Power lead
• 1 x USB adapter plug
• 4 x Mobile phone adapter plugs
• Instructions