Plz help newbie gateway nv55c just dies without warning not heat ??

I got this gateway nv55c laptop got so much data user accounts i cant begin to start replacing it . i do have all my data backed up thats a must keep .. that said i really need to fix this ..

It keeps going dead .. says battery has charge like 70% then just goes black ..
I did read first and saw heat was often the culprit .. I blew out the fan slot vacumed it got little bit out but didnt seem real bad .
i fired it back up and it ran for 10 minutes and shut down again . I dont mean like loggin off i mean like boom dead black screen , I just plugged it in the wall and going to run it on charge a while and see if it does it again .. .. could this be a bad battery ? or would it show the battery charge drop way down before dying ? Please anyone point me in right direction
thanks guys and gals and thanks for adding me to the group

 

Running on battery showing 70% you should expect at least a couple of hours of work out of it... but if you're only getting 40 to 70 minutes run time... You should really think about replacing your battery

It does sound as if your existing Battery Calibration Program as shown by Windows is way out of kilter.

Can you download and install BatteryBar a program that will check out and show you the actual battery status.- it is available at the web address below...
BUT - they are 'pushing' the PRO version... So, SCROLL DOWN to the bottom of the page and click on Try Basic Version

https://batterybarpro.com/

It is Normal to Charge a battery to Full (100%) then OFF the Mains electric, run it down to 20% (while watching Youtube or doing your Thesis... THEN recharge it back to 100% ..- this should be done a couple of times BatteryBar can then show you what state your battery is in...

That is Estimated run time of the battery and the amount of wear
1% is a maybe 1 month old battery... 68% is Time to think about replacement...

 

How hot is it where you live right now? Laptops have all their little mechanisms in close proximity, so they tend to overheat really fast. If you're not running a cooling fan beneath your laptop, you could be having issues with over heating. Just clearing the dust out isn't going to deal with things heating up inside, so a fan really helps. My laptop is eight years old, and quirky, but it still runs and does what I ask it to. I always plug in the cooling fan first before attempting to run the laptop and believe me it makes a tremendous difference. If you've ever rested your computer on your lap, you'll know how hot the bottom of the machine actually gets. Inside it's even worse, so yes, cooling is really necessary... especially during hot weather or when living in hot, muggy climates.