Item nr.

Xtorm AS103 Solar power bank

Power bank hub

Data for Xtorm AS103
ProductionThe Netherlands, 2012.
Price was 30€.
CabinetPlastic. Size 14x5x3cm. Weight 85gr.
PowerSun, USB, crank.

The Design

The Xtorm AS103 was designed for travel use. You can use it to charge mobile phones by solar power, but it also contains an internal rechargeable battery (3,7V at 800mAh), a torch, an alarm siren, and a port for charging it by a USB port. And in case you'd like some exercise, a hand cranked generator. I see the use of such a unit in poor countries without electricity, but always doubt if Western travellers will use it.

Obtained9/2019 from Kringloop Het Goede Doel.

This Object

The crank for manual charging was removed and the space used for two more connectors: an external (larger) battery and an external (larger) solar panel can be connected, disconnecting the internal battery or panel. My battery is a wood box, containing three 18650 cells, a fuse, and a (switchable) voltmeter (drawing 11mA when on).

First tests revealed a shut down problem. When plugging or unplugging the external battery, the main board suffers a short power interruption and this causes it to shut down. It only returns to working state when power is applied (from either the solar cell or the USB port). So I added a 470uF capacitor to the battery connector, enough to provide power during these few milliseconds, provided no external applianced are powered at that time.

Then, the hardest part: the usability test. I fielded this energy conversion and storage system in combination with a small solar panel and an amplifier in my office, facing directly south. I usually keep the amp switched on when I leave the office for the night, but switch it off for weekends. I was able to run the amp fully off grid during the winter months, November through January. Nice experiment, but let us see, how much does this save me... The amp consumes 0.3W when playing from an adapter, which is switched off also during weekends, so the yearly power cost is about 20 to 30 cents. So I terminated this succesful experiment and feed the amp from the adapter again.

Part of Gerard's Radio Corner.
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