#Arduino low battery indicator how to#
#Arduino low battery indicator full#
#Arduino low battery indicator code#

Debouncing Circuit: Works fine (image 3).Test3: Circuit with Debouncing/Load disconnected: Low Battery Indicator: Blinks when switch is pressed.Debouncing Circuit: The voltage drops to 2.19v at the output of the Smichtt Trigger, therefore it isn't possible to energize the Step Up and the rest of the circuit.Test2: Circuit with Debouncing/Load connected: Voltage drops from 3.68v to 3.46v (image 2). Test1: Circuit without Debouncing/Load connected:

#Arduino low battery indicator full#

I added a debouncing switch and it works, but it fails when added to the full circuit (image 1). I would think of something like an averager or a rounding method, the problem here is that I do not use a microcontroller in the system to store values or program it to round values, everything is analog. Is there any artifice I can implement to avoid detecting small variations in order to generate an immediate change from OFF to fully ON at the set voltage? My circuit consumes 0.23A and is supplied by a 3.7v/1400mAh Li-Ion battery.Īt which the led should light up, indicating 'low battery'.įor example, if I set 3.3v as low voltage, when you change abruptly from 4v to 3v the led turn on immediately, but if you leave the battery discharging, as would naturally be the case, there is a time lapse in which it start diming gradually and blinking until it lights up completely. I have been building some circuits to turn on a LED when the battery is low (images), but there is a problem: The led dim and blink between the OFF and fully ON state for some minutes. I think this part is getting much more complicated as it will be drastically affected by different battery capacities (Faces kit or the battery stack units etc.) as well as the current draw - this is not so much the case with Step 1 so step 1 would be much more universal function and I think will remain reasoably accurate across battery capacities.Hello! I would be very grateful if you can help me with that. It could mimick that curve exactly at every percentage point using only 100 float values - and a very simple function:īyte returnBatteryLevel(float would you be willing to share that spreadsheet with me so I can pull the voltages out? I'd be happy to commit this function back to the M5core2 master so we can all report (more) accurate getting to a projected time left would be a step 2 in this process - the first being getting an accurate percentage left, the second projecting how quickly this will diminish based on knowlegde of the battery and the current draw. The most accurate and lightweight solution would be a lookup table. I've observed the same phenomenon in reverse when charging - it looks like you are charging really quickly because you hit 45% really quickly then it takes forever to make it the rest of the way - no wonder - you're only 20% charged!

#Arduino low battery indicator code#

Great thank you! It's the super steep drop off at the end that is messing with everything as the algorithm in the example code just draws a straight line from 3.2v to 4.2v so up until the steep drop off it says you have almost 50% more battery than you actually have! at that dropoff point the voltage is about 3.65v - so the percentage calculation at that point in the graph will read 45%!!!

#Arduino low battery indicator how to#

Upshot would be it will be much more accurate than this basic linear calculation is - so I'm going to do this said in Core2 how to know the current battery level:Īs you can see the line is reasonably linear until the very end. We could also build tables at different consumptions/temperatures if we wish as this will all affect when the 'last 20%' fade kicks in. Then I can build a lookup table to represent this in code for this device. Then we can build a graph - just like the one I linked to based on the specific battery in this device - a new, healthy battery at room temperature - using a fairly normal level of power consumption.

Leave it to run down, pinging out to sdcard its battery voltage, current draw (for information) and the time elapsed. We can extrapolate that as being a total life of 1 hour and 15 minutes - based onthe last 20%ĭoes anyone know of a better curve solution someone has already done?

You can see this shown in the graph above for Li-ion batteries (i dont really know how close that is to the real performance of these batteries. My little Core2 lasted for 5 hours and 40 minutes.Īt about 5 hours and 25 minutes it was showing 20% (my battery meter turns red at 20% :) ), but the last 20% dropped off in 15 minutes. I implemented and tested this last night While the calculation in the m5core2 factory test is linear - the battery performance is not.