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Unread 25-12-2012, 18:33
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Re: paper: Battery Voltage in Robot Drivetrain Simulation and Modeling

Quote:
Originally Posted by AllenGregoryIV View Post
What other ways have people optimization power flow? I remember reading something about Jim Zondag figuring out a way to optimally charge the minibot batteries before matches in 2011 anything like that for standard FRC battery?
We never did a ton of analysis of charging FRC batteries, but we did some for the minibot batteries.

Since the use time was so short, we were trying to push the charge (and surface charge) as high as possible, as quickly before a match as possible (to reduce fade of the surface charge). We ended up with a cycle using 2x RC car battery chargers. One was 115vAC powered, with our battery cart, and would charge it 'normally'. We would then put the charged battery into the minibot (where it was secured with zip ties), and leave a lone zip tie sticking out and the minibot power switch off to indicate that the battery was disconnected. Before a match, we had another 12vDC powered battery charger (running off a robot battery) which would very rapidly (40s or so) top off the battery at a very high charge current (10a or so), then we would zip tie the battery connection and go onto the field.

We tested the charge profile using a battery discharger (functionality included in one of the RC car battery chargers), to verify the length/current of the top-off charge. It was a fairly time consuming process. Eric Yahrmatter did most of it. We did all of this development mid-comp season, we didn't use a special charge process at the first two or three competitions, but we did have many batteries and chargers in parallel then.

A cycle like that wouldn't work nearly as well for normal FRC robots.
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