#Arduino lipo battery monitor code#

This +5vdc voltage will be slightly different when changing from external voltage to USB voltage. The standard Arduino A/D setup is using the board's +5vdc Vcc as the measurement reference. Keep in mind that you will have other 'calibration' issues to deal with. Yes, cell one's terminal will only go as high as 4.2vdc (at max charged cell voltage) so it can wire directly to a analog input pin as it will 'fit' in the standard 0-5vdc range of the processor chip, no voltage divider required. But can I just plugin the '+' of that cell right into the analog-in? Did not dare to try it without resistor. My previous circuit did work, but not correctly?įor cell 1, I don't need a voltage divider, it's never going over 5v. Is my circuit correct, but do I need different resistors to not divide it? I just tested it, I get a reading of 1.88v on cell1, thats not correct, why? It seems I divided the voltage by a factor of two. If I understand correctly, it should look like this. So the Gnd are always attached, but the test I did was with a 12v battery, so I needed to connect '-' somehow, without it the reading was all over the place. The lipo also powers the arduino from Vin and Gnd. But that way, cell 4 will be less accurate than cell 1 reading because of it's higher voltage. It's good enough to make 4 different voltage dividers. Thats the most accurate, but I have no idea to do that. It's more complicated.Īnd even more complicated to make ranges like, cell 1 2.5-4.5v, cell 2 6-13v. So if I want more accuracy I need 4 different voltage dividers that need different code. So it can handle the reading of cell 4.īut that cost me accuracy because cell 1 only read 3-4v.

I need to use one type of voltage divider that can detect up to 17v. And cell 4 may read 14.8v, subtract all other cells to get cell 4 voltage.īut to make ik easy.

So the scripting must subtract cell1 from the reading of cell2 to show cell 2 voltage.Ĭell 3 may read 11.1v, and need to subtract cell 1 and 2 to get cell 3 voltage. So to see each cell voltage I need to calculate it.įor example, cell 1= 3.7v, it reads 3.7v, easy.Ĭell 2 may read 7.4v. Remember, I'am a noob, so every advise must be in noob language.īecause at first I tought I could read 4x 0-5v.

#Arduino lipo battery monitor code#

But this plan isn't going to work I gues.Ĭan someone help me with monitoring all 4 cells? And help me with a circuit drawing? I don't know how exactly use a voltage divider, and what code I need for that. And calculate the total voltage by counting all cells together. My plan was to display all cells on a lcd display. I read about voltage dividers, but I gues I need a different divider for every cell :o This makes it verry hard for me to simply monitor all cells. So it's was in serie, and the next cell and the next were also in serie. I tested it with my multimeter, and it was 7.54v. And I gues I need a 4pin on/off switch to turn on and off both the - of the dean plug power cable of the lipo, but also the - on the recharge plug to prevent power loss on storage.īut I want to monitor all 4 cells at the same time, so I first tried to read the second cell, and arduino displayed 4.94v! I first tried to use only one 10K resistor, it worked, but the power led on the arduino started to burn, even when it wasn't connected to USB, so I gues the arduino is using it as a power supply somehow.īut even with the resistor it is using power. This way I could read 3.71v on the serial. I used 2x 10K resistors, didn't know how it supose to work, so I just tried.

I'am a Arduino noob, but I managed to monitor one cell. I have a 4 cell lipo that I want to monitor with the Arduino Duemilanove.