I have been working with LIPO batteries to power my portable projects for a while (mostly in RC aircraft), but when using them, I have always had to guess as to how much charge is remaining. Now, I am trying to build a system to provide a more accurate estimate as to how much charge is available.
So, I was thinking, I know how much the batteries get charged to, so, if I can measure the amount of current that is being drawn during its life, I can estimate how much longer the battery will keep operating.
Sadly, I am not to sure how to go about measuring this usage. I have a larger LiPop 4s battery (14.8v, 10000mah), and 4 180w brushless motors. This works out to around a maximum of 50A (each at 12.2A) being drawn by the motors at full power.
So, I want to measure the amount of current being drawn by all the motors. But, all the components I have found have usually maxed out at between 20A and 30A, so not enough to measure the usage if all the motors are going at once.
My solution to that was to measure the current being used by each motor. If I was to get 4 digital ammeters, and connect one to each motor, would that cause any problems? And would it be able to accurately measure how much current is being drawn without interference from the others?
Also, I have been searching several sources for digital ammeters, and there appears to be quite a range, and I don't want to get it wrong and damage my system/waste money, so If anyone could recommend a suitable Current Sensor I could use (the interface doesn't matter too much, as long as I can connect it to an Arduino)