You’ve probably noticed that an Ameo/Advantage X7500 when seriously hammered (photography, mp3 listening, watching video, web browsing) can be drained full to flat in little more than 5 hours. Clearly it’s not always possible to have a second battery, but here’s a cool emergency solution (pictured).
Take a cheap rechargeable burglar alarm battery, take an in car USB charger, remove the end cap and pull the spring under the +ve terminal, then slot the side -ve tabs onto the other -ve terminal.
Note that the USB charger should have an output of at least 800mA otherwise your Ameo won’t actually charge.
A 3.2Ah battery (pictured) is good for around 2 full charges from empty, whilst a big 7.2Ah battery will get you about 5 charges. Twin this with a Maplin solar trickle charger and you have a ready source of power for charging the Ameo on a long trip.