OBS is KILLING killing my Macbook battery......

Hi, I'm live streaming using a Macbook, however the battery literally is lasting 20 mins on a full charge, everything slow & my CPU is running at between 70 - 85%, I've tried everything I can think of including resolution size of images, deleting videos but still its not made a difference.........

PLEASE HELP ME
MacBook Pro (Retina, 15-inch, Mid 2014)
2.2 GHz Quad-Core Intel Core i7
16 GB 1600 MHz DDR3
Intel Iris Pro 1536 MB
Catolina OS 10.15.7

real-time video encoding is really hard work. really... your OBS settings can then make things better or worse, depending on what you are trying to do,
and you have an old computer
so this is all about expectations. OBS is working for you on an old laptop - congrats.
An old battery dying quickly after sustained high CPU usage... expected. Getting a new battery would likely help.. a little.. ,If your system is on a HDD instead of SSD, upgrading that would likely help ... but I wouldn't recommend either. Your options would seem to be:
- Plug in the macbook,
- look up settings for OBS and under-powered computers to reduce compute load
- or get a newer, more powerful computer

Im in a similar situation with a 16" Macbook Pro with a Core i9 so I agree that optimisation is going to be important for you. If you're able to re-encode your video assets into a more streamlined format for OBS and the CPU to work with. Avoid having things sitting in RAM if possible buy using the option to not have things loaded with inactive. However this might result in a slight delay when you request a video reaction asset, depending on how quickly your CPU and OBS can load and decode the video.

Overall without knowing more about what you have going at any given moment its hard to say which optimisations will yield the best results, so I would suggest looking at the most optimised formats for the sources and assets on your stream, if an image is scaled down, re-create it to be the "right" size so OBS doesnt need to do a transform etc. Just try and make everything the lightest version of itself :)