Warning: electronic n00b help
I’m looking at trying to read voltages of individual cells coming off of a multi-cell LiPo battery via my CerbDuino.
The cells in the battery are wired in Series. Using a voltage divider I can make the voltage acceptable to my ADC pins.
The cells are 4.2v so the individual cells should read out a max of:
cell1 = 4.2v
cell2 = 8.4v
cell3 = 12.6v
So I understand that my the R values are different for cell1 vs cell2 vs cell3.
Questions:
-
Is the wiring in chicken scratch illustration correct to accomplish, with no short circuit effects?
-
This will hopefully eventually reside on a custom PCB with SMT parts.
a) I was thinking about 0603 or 0804 - any reason these wouldn’t be able to handle the higher voltages? For example, if I went to a 4 cell, so that would be a max of 16.8v.
b) Would going to a larger size (0804 or larger) resistor help with heat dissipation?
- Is there another way, like an IC, that would accomplish what I am trying to do? I’m looking at a I2C chip from Ti that will do this as well, but it’s a 30 pin chip, which seems a bit of overkill from what I am trying to do. Sparkfun has a chip based fuel gauge, but it’s only for a single cell.
Thanks for the help/suggestions