Charger icon not changing but charger is working

Recently I bought a charger for my HP G61-110SA which was just a replacement adapter. Now yesterday it did something weird. Basically, there are two pictures of the two indicators there are to show whether it is charging, one is on the front and one is next to the port on the side. Basicaally the charger wasnt changing the indicator on the side or the one on screen but the one on the front was working when I turned it on. By default the laptop chages brightness when plgged in but now it sort of brightens a bit (not to the full level as should do) and then goes back to normal. Today the laptop is still doing the same but the front light now only turns on for a few seconds before turning off! I dont know whether it is charging. Is this the laptop or the charger. Any help would be useful, I have attatached the side indicator and the front one

UPDATE: I found a website which said you could turn it off and start without battery but with charger and then turn off and use both. However, I turned it off and removed the battery and it wouldnt charge. Then I put the battery in and it started charging-weird. Also the light on the front doesnt last very long so I am stuck. ANY HELP?