I've an opportunity to pick up an Apollo Pico in my pricerange. My main concern is the battery replacement. Apollo says it's not user replaceable but the replacement guide (available from Google) makes it look fairly straightforward. It seems that it's sealed with a simple gasket, and not coated or packed in any way. Am I missing something? Does anyone know what size battery it takes (ie is it something I can easily get or a customish jobby)?