Dell Latitude E7250 noisy and running battery down too fast
I am out of ideas. The laptop became noisy a couple of weeks ago and I noticed I had to keep charging my battery. Dell came in and changed the heat transfer unit (not sure if that is the name for it) and also new motherboard . I asked the technician to update the bios which he did as I wouldn't have a clue how to do it, Basically the noise was still there although admittedly less noisy but battery only lasting a 90 mins or so. I decided to buy a new battery (expensive). It arrived about 3 or 4 days ago. Great - silence!!- Noise gone and battery lasting 5+ hours. Now the noise has restarted and battery is lasting a lot less again 2-3 hours . At this present moment the noise level is there but not terrible and battery says 37% - 1 hour so as it should be. When charging the noise level is far higher.
i really don't know what to do - I have updated Windows 10 today in case that would help and have shut down and restarted a couple of times. Laptop is 3.5 years old and very well used. I know the storage is going down and I have about 20gb space left and keep moving stuff onto the E drive where I keep a memory stick in.
How can I get it the laptop silent again like it was immediately I got the new battery a few days ago and therefore the battery can last longer please? I know more than the average person but not fabulously computer literate so please make any instructions to try straight forward for me . I am now being told that I have 50 mins left which is 30%!! This is ridiculous with a brand new battery which was perfect a couple of days ago.