short question..(probably a long answer)
i intend to use a liion battery (link to ebay)from an ipod to power a design, but want to use a USB charger IC, say this one on the farnell website made my microchip:
http://uk.farnell.com/microchip/mcp73837-fci-un/liion-charger-usb-dc-in-10msop/dp/1675426
two questions..
1) does a single liion battery count as a cell? the datasheet mentions charging a single cell.. but im unsure whether the battery i want to use is a single cell?
2) With the charging of this battery, if the usb in was disconnected, would the charging IC > battery connection need to be broken/switched open? in order to work properly?

 

The link says the battery is 3.7V so it is a single cell. It is not Name-Brand so it is probably cheap and probably has poor quality. It might be old. It might not even work.
The Li-Po batteries for my RC model airplanes are Name-Brand and are the latest 6th generation that work much better than older generations.

My friend bought 10 Chinese Li-Po batteries from E-bay for a low price. They barely work and are garbage.

 

many thanks! ill give the ebay ones a go, prove the concept and see how they do, the ipod replacement stuff on ebay seems to be quite good from what iv found (screens anyway)
but like you say, batteries are a different kettle of fish, is easier to bodge a battery than an ipod screen!