Charging problem

[Merkuu]

I have a problem. When I put the phone on charger it powers on and says insert SIM (it's inside) and there is no battery icon and it won't charge. And I can't start phone at all. It only starts when I plug the charger and... I described what happens. I have a desktop charger,so I charged the battery but I still can't start the phone. When I go to BL it says low battery aldo it's charged. What could it be?
And yea, my phone is ROKR with 07.D0 BL

[the me is three]

Try to change with the new battery

[kambingjantan]

try to charge your batery with destop

[oniech]

Try jumper like this