Hello, it's me again. Back with another question I'm hoping someone can help me with please.
The project I'm working on at the moment is going to be powered by a 12V 7Ah Sealed Lead Acid battery (Model: NP7-12TFR if that helps).
I want my project to monitor its own battery health so I turned to a library I've found on GitHub called Battery Sense. GitHub - rlogiacco/BatterySense: Arduino library to monitor battery consumption
I am using an DC-DC converter to step down the 12V to 5V for powering my project so I built my sensing circuit based on Sections: Higher than 5V, with external voltage regulator and Higher than 5V, activated on demand.
What I ended up with was the On Demand Circuit placed between the battery and the DC-DC converter as shown in Higer than 5V with external regulator.
I'm almost certain I've followed every instruction to the letter including the recommended VoltageReference calibration and I am getting a reading but it doesn't appear to be changing.
Yesterday the freshly fully charged battery was at 13.314V according to the battery sense sketch and today it reads the same?
I verified the reading yesterday against my multi-meter and it was pretty darn close but today my multi-meter is showing 13.093V but the sketch still says it's 13.314V.
I have checked, checked and triple checked the circuit wiring for mistaks I may have made wiring it up on breadboard but as far as I can tell I have reproduced the circuit exactly and the values for the resistors are correct. I have also verified that my ratio values are correct in the library as well as the true voltage. I have defined correct upper and lower (MIN MAX) battery values and that all the pins used are wired to the correct places.
I just can't understand why the reported voltage isn't showing any drop.
Basically the circuit is just a simple voltage divider rated to handle / read 12V batteries and it's switched in and out of circuit using a 2N7000 Mosfet. It all appears to be working except the readings don't seem to be changing at all.
Obviously I know these battery monitors aren't super reliable or super accurate due to so many influential factors and variables but I just want some rough idea of what the battery is doing.
Sorry if that's not enough or is too much information. If any more information is needed to help diagnose my problem just ask and I'll do my best to provide it. In the mean time I'm going to keep working the problem myself. Naturally if I get to the bottom of it before anyone has an answer, I'll post back with the solution.
Many thanks!
Thanks!