Hello forum, I am new here and really I am only here to ask some you all a question in hopes of possibly helping me out. Here is the question (and yes I briefly skimmed through to find the question, it was not answered in the capacity I was looking for).
I have a device (PSP), and a Battery (It's personal one). I want to find the average draw on the battery form the device in a manner that will allow me to apply this to other batteries (portable battery charger packs) to find out the most efficient battery in terms of not just longevity (obviously that's what the mAh rating is for), but also being able to calculate the average life expectancy of the battery. This is what I have so far:
The battery is 3.6V at 1,800mAh, meaning the battery will provide a current of 90mA at 3.6V per hour for 20 hours in an ideal setting. I have no idea if it is possible to figure out how much watts or how many watts total a battery can pump out at any time.
The device is rated to draw at a maximum, 5V at 1.2A, which means at maximum power consumption (which is never) the device will draw 1.2A per hour at 5V. Due to the equation W = A * V I know the maximum watts this device uses at any given time is 6 Watts.
Being it is a PSP, it obviously does not last for 1 hour, so the AVERAGE draw is not 5V at 1.2A, or my battery would drain faster then 1 hour every use (since a battery draws faster if being used at a higher voltage then rated and at a higher mAh then rated per 20 hours).
This is what I have figured out already. This is what I need to know:
Equation necessary to find out a rough estimate of the devices mAh draw on a battery, as well as its draw when drawn at a higher voltage then rated, or a lower voltage then rated.
How to find a devices average draw per hour having the devices maximum voltage, amps, and watts possible. (would I simply half the voltage and amp's the device is rated for at maximum? or could I use an equation much like the first question asked).
With these questions I should be able to look at any device, any battery, and do the math to figure out how long the device should run at an average setting or maximum power consumption setting with the battery in new condition, and guesstimate its power over its lifetime.
I have not taken battery materials into factor even though I guess I should, If I am correct different types drain at different speeds as well as self-discharge at different speeds, but Li-Ion batteries are pretty much the standard in rechargeable batteries so I would imagine it would be worthless to take that into account.