For those who like to go camping, kayaking, hunting, or other outdoor activities that can take you away from civilization for days at a time, keeping your cell/satellite phone charged for emergencies can be an issue. There are options out there of course, and all of them have their benefits and their limitations. Whether they are small wind turbines that you can attach to your bike, or portable solar charges you can use during the day, most of these systems are for instant use charging since few of them store power on their own. The Estream hydroelectric system is limited to use in running water, but it offers the benefit of power storage that can be used for up to 3 full charges of a smart phone once fully charged.
The Estream is about the size of a water bottle, so it won’t take up too much space in your pack and it has a few other features built in, and expansions are possible due to its modular design. For now, it can be used to charge any USB device, and it operates a lamp with a strobe/signal feature for emergencies. You use it by anchoring it on land and just letting it lay submerged in any running water source. It can also be tied and towed behind a boat/kayak to generate power while you are taking in the scenery, fishing, or moving from one location to another to set up camp. By setting the Estream up at night, you can have a fully charged device to recharge your phone, laptop, camera, or other USB gear the next day.
A personal hydroelectric plant for camping or survival could be a great addition to your pack and even if you have other off grid charging devices, the ability to store energy would be a great supplement or backup to your existing survival gadgets.