RE: BATTERY CHARGING PROBLEM (BATTERY NOT IDENTIFIED)
As advised by ejn63, if you have tested different batteries and adapters and the battery still would not charge, the motherboard might be at fault.
If the system is under warranty, Please click my DELL-username and write me a private conversation with the service tag and your contact details(Name and Email) and we could arrange for a service call. If there is no warranty, then you could contact our team to get a quote for a paid service call - http://dell.to/1vnT6CQ
Let us know if you have any other queries.