View Single Post
  #10   Spotlight this post!  
Unread 09-12-2013, 20:29
yash101 yash101 is offline
Curiosity | I have too much of it!
AKA: null
no team
 
Join Date: Oct 2012
Rookie Year: 2012
Location: devnull
Posts: 1,191
yash101 is an unknown quantity at this point
Re: Ranking batteries using a Battery Beak?

Quote:
Originally Posted by DonRotolo View Post
The CBA4 is great for overall battery health, but not readiness for a match.

Internal resistance indicates the maximum current the battery can deliver, the lower the resistance the higher the current.

State of charge tells you, with some small inaccuracies, how fully charged a battery is, meaning is it ready to do its thing.

V0/V1/V2 tells you what kind of use you can get from the battery at different current draws, and for FRC the 18A value is the most useful. These values are somewhat related to internal resistance.

To determine which is the next battery to use in a match, we check SoC only, if it is OK we go with it, otherwise find another battery to check.

We do rank our batteries on internal resistance, the lower (better) ones get more play time.

Eventually all batteries go bad - then we recycle them...
Yes. The internal resistance is a big thing. When you suddenly push the joystick all the way forward, you will notice a voltage drop. The higher the battery internal resistance, the greater the drop will be. E=I/R is what Ohm's law says. That means, if I am right, that the voltage drop will be the current draw divided by the internal resistance of the battery! That makes me think, Ohm's law will allow me to find out how many amps are flowing through the battery at any time!

^^Darn it! Why didn't I remember that at vegas? That would have given us the problem solution within a couple minutes instead of a couple hours^^

Also, that may be why our battery wires were starting to melt a little!