BatteryBeak: Utility of making internal resistance and state of charge measurements

[WinDnDusT]

Hi all,

I’m attempting to learn useful ways to track battery health/status using the Battery Beak. I’m looking for verification on the things I’ve learned and any suggestions the intelligent, experienced people like you can provide.

I plan on using the Battery Beak on the ES17-12 battery model from MKPowered. I’ve met some resistance (no pun intended) from members on my team that think the Battery Beak is too simple and underplay the utility tracking the internal resistance of a battery can offer. I want to convince them otherwise.

From my understanding, tracking the internal resistance is useful for the following reasons:

1. The first measurement done with a new battery allows you to see if the battery matches the manufacturing specification or if it deviates (and the size of that deviation)
2. The health of the battery (the physical condition of the individual cells and of the electrodes and electrolyte of those cells) can be determined from measuring the internal resistance.
   • No change or a small change can mean a battery is eligible for competition.
   • A medium change from when the battery was new can mean a battery is eligible only for practice or workshop testing.
   • A large difference from when the battery was new can mean a battery is eligible only for laptops in the stands but not robots
3. The treatment that a battery is given and/or manufacturing defects. By noting the speed at which the internal resistance changes (by calculating the slope of the function describing the internal resistance measurements), one can determine if a battery is receiving proper or improper treatment over its life. If the measurements show a sudden jump, this could indicate a situation where a battery cell has failed.

Simply put, by the end of build season, batteries with low internal resistance and slow growth in their internal resistances are prime candidates for use in competition.

Are there any issues with my understanding or useful reasons I’ve missed? Do any other teams track internal resistance through time?