My Dell Inspiron 1525 not charging battery?

Get a new battery, your is obviously dead.

Some Li-ion battery maintenance tips:
Only recharge when under 10% remaining charge. You want to minimise the number of recharge cycles as much as possible. Recharging from a 99.9% charge count as a full recharge cycle the same way as recharging from 1% remaining charge.

Always recharge as soon as possible if the charge ever drop to 0%. Leaving those batteries totaly drained will kill them in only a few hours.

It may be a good idea to have one or two spares that you can swap when the charge drop to around 5%. This is important if you often use your laptop on the go.

Electro
December 2012