One for Mr Lutin Ibthink.....I bought a portable power bank from Aldi today -£9.99 for 7800 MaH. Lithium Ion batteries. A bargain I think. It has two outputs one rated for 5v 1Amp, the 5v 2.1 amp. I mostly want the thing for recharging mobile phones and Bluetooth headsets when camping. Question - if a plug my phone into the 2.1 amp output will it damage it? My phone needs a 0.5 amp charger but has always been fine plugged into a 1amp device. But 2.1amp output may be a bit too much. I always assumed a device could only consume the power it needed and if more power was available it didn't get used. Eg, mains ring at home rated 30amp but if I plug in a 60watt bulb (0.25amp at 240v) the 30 amps available does not damage the bulb and I only use 0.25amps worth of electricity. Is it the same for charging batteries or does the battery just suck up electricity as fast and as much as it's available with potential damaging effects.