Intel's website shows the processor in your laptop as falling into the group known by the code name of 'Sandy Bridge':
https://ark.intel.com/content/www/us/en/ark/products/53452/intel-core-i5-2450m-processor-3m-cache-up-to-3-10-ghz.html
This page shows that Sandy Bridge was the code name used for 2nd Generation Intel Core Processors, which do NOT support Windows 10 drivers:
https://www.intel.co.uk/content/www/uk/en/support/articles/000006105/processors.html
So it's possible that your processor is struggling to cope with Windows 10. (I recently made the mistake of 'upgrading' a laptop from Windows 7 to Windows 10 without first checking whether the processor was really up to the job and now I'm regretting my action!).
Open Task Manager (via right-clicking on the task bar at the foot of your screen). Select the 'Processes' tab. Click on the 'Power Usage' column heading in order to put any power hungry processes at the top of the list. Look to see if there's anything showing as 'High'. (You might need to keep checking it periodically to see if, say, there's an updating process that's drawing all the power from time to time).
Or, as Ginge suggests, just use your laptop on mains power all of the time. (I suspect that well over half of laptops are never used on battery power. Most people seem to use them in just one place and leave them permanently connected to the mains adapter; it does them no harm at all).