After TEOTWAWKI there will be enough regular batteries to last us a while, but when they all run out there will be some savvy survivalists using rechargeable batteries. But how to recharge them if there is no electricity? Here are some ideas, but you need to buy and use them now. Unless noted, they charge your devices directly.

BikeCharge Dynamo. Dynamos have been on bicycles for decades to power lights. This one will charge your batteries. The Dynamo ($120), attaches to your bike’s wheel; the Power Converter ($30), turns the energy from the turning wheel into usable power; and that power is stored in the 2,600 mAh Power Pack ($59.99). Use the Power Pack to charge devices via its USB port.

PowerPot. For $150 you get a little camp stove that, aside from boiling water or cooking a meal, charges your device at the same time.

nPowerPeg. If there’s one activity you are almost guaranteed to partake in after the SHTF, it would be walking. This $200 device is powered by you, just by doing some walking. Kinetic energy.

Eton FRX4. Powered by the Sun, or via a hand-crank. Splash-proof and drop-proof. Includes a radio and flashlight. $80.

Mercury 4-S Ultra-Slim. Foldable solar panels. Cheap, portable solution. $33