Dell inspiron 6400 battery issue

I have a Dell Inspiron 6400 and it seems to be giving a false reading on the battery charge.

Right now there is a battery connected but the power meter indicates that there is no battery. The first battery i had was working fine before it suddenly would not charge beyond 5% or less. Since it was over a year old I got a new battery which worked fine for a few days containing almost a 3hr charge. Suddenly it dropped down to 5% (orange light blinking) and sometimes indicated that there is no battery present.

I presume this is a motherboard/bios issue rather than the battery.


Any advice/ suggestions?
Thanks in advance