Laptop will not power from battery

I have an Acer Aspire 7551G that will not power from battery, the AC adapter must be connected for the machine to boot and as soon as the adapter is removed the laptop instantly dies.

The contacts have been cleaned so there should be a good connection between laptop & battery.

Additionally, Windows is aware of the battery, insofar as when it is removed the battery icon changes to a red X to indicate no battery is present and if you reconnect the battery, it switches back. Some times the indicator will show the battery as charging other times it shows as not charging.

Additionally, some battery info tool can get the brand, model etc of the battery as well as current charge level - but even after a good 30 mins of charging the charge level does not charge.

It is almost as if, the power circuit from the battery is broken but data circuit is fine - that's a wild guess, I've got no real idea of how batteries work haha.

It's worth noting that I am only experiencing the issue having replaced the thermal paste on the CPU due to overheating issues. Additionally, I am still seeing these heat issues which strikes me as a little odd...

Hope someone can help me here!

It is just a coincidence that your battery has gone bad at the time of your heatsink work. Unless there was a connector overlooked that had to do with the charging of the battery. Of all the CPUs I played with in different laptops, I never seen a cable pertaining to the charging. Its always part of the printed circuitry of the motherboard. There is always a first time though.

The symptoms you describe are a dead battery, the overheating issue is part of another subsystem, part of the whole working unit, but working independent of each other, separate from the battery.

With the overheating, the fan interior needs to be blown out if you removed it totally. Blow the air the opposite away the air normally flows. Check cavities in the path of airflow, blowing them out with compressed air. Do not make the fan spin up too much with the compressed air, I understand it is bad for the fan to exceed its working RPM too long, even though it is being powered by a can of air. If all that was done the first time, now is the time to consider the thermal grease you are using. Anytime I take the heatsink off of a desktop or laptop I use Artic Silver 5 as my thermal paste of choice. It is reputed by many to be one of the best conductors of heat out there for CPUs. It is mainly used by overclockers, but in your case where you laptop is overheating still, I would take the extra step of prevention.