Macbook charging problem

The wifes macbook seems to have developed a fault,

I took the battery off to change the ram, Now the battery wont charge, disconnect the power, bye bye!

have tried taking it off and putting it back on but to no avail!

Help please

Have you tried going in to System profiler and seeing what it says about the battery?

ok, here is what it says in profiler
AC Power:
System Sleep Timer (Minutes): 10
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 10
Automatic Restart On Power Loss: No
Wake On AC Change: No
Wake On Clamshell Open: Yes
Wake On LAN: Yes
Display Sleep Uses Dim: Yes
Battery Power:
System Sleep Timer (Minutes): 10
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 2
Wake On AC Change: No
Wake On Clamshell Open: Yes
Display Sleep Uses Dim: Yes
Reduce Brightness: Yes

Hardware Configuration:

UPS Installed: No

AC Charger Information:

Connected: Yes
Charging: No

Battery Information:

Model Information:
Manufacturer: DP
Device name: ASMB016
Pack Lot Code: 0002
PCB Lot Code: 0000
Firmware Version: 102a
Hardware Revision: 0500
Cell Revision: 0102
Charge Information:
Charge remaining (mAh): 0
Fully charged: No
Charging: No
Full charge capacity (mAh): 0
Health Information:
Cycle count: 15
Battery health: Poor
Battery Installed: yes

any ideas?? I'm confused!!

I cant seem to find anything in settings either

It seems like it's recognizing the battery. I'm guessing with only 15 charge cycles its is a fairly new machine i would give Apple a call or book it in. I can't see how taking it out to add more RAM would damage it. Have you checked the contacts?