How often do you change batteries?
 

Posted by Joe Ross at 2/6/2001 12:45 PM EST


Engineer on team #330, Beach Bot, from Hope Chapel Academy and NASA/JPL , J&F Machine, and Raytheon.



Is it after a certain number of matches, or when the voltage reads a certain level? Do you have some other really cool way to determine when to change batteries?

Do Tell

Re: How often do you change batteries?
 

Posted by Patrick Dingle at 2/6/2001 1:04 PM EST


Other on team #639, Red B^2, from Ithaca High School and Cornell University.


In Reply to: How often do you change batteries?
Posted by Joe Ross on 2/6/2001 12:45 PM EST:



Last year, I was more or less in charge of swapping the batteries for my team. Basically, we swapped them immediately before EVERY match. During the nights we hooked up the two batteries in parallel and charged them both.

Patrick

: Is it after a certain number of matches, or when the voltage reads a certain level? Do you have some other really cool way to determine when to change batteries?

: Do Tell

Re: How often do you change batteries?
 

Posted by Al Skierkiewicz at 2/6/2001 1:24 PM EST


Engineer on team #111, Wildstang, from Wheeling High & Rolling Meadows High and Motorola.


In Reply to: How often do you change batteries?
Posted by Joe Ross on 2/6/2001 12:45 PM EST:



Now that Innovation First has provided battery monitoring on the interface we have come to trust this as the best indicator. During competition in 2000 we experimented with nondriving current draw that would give us terminal voltage under load. For us it was driving two Fisher Price motors at full speed. When the battery fell below 11 volts in this condition we became ready to swap, and below 10 volts was a mandatory swap. Remember that motors will run all the way down to zero volts but the interface has an internal 8 volt regulator. Fall below that voltage for a short time and you will reset the micro and wait for at least two seconds before the micro reboots. A good indication of reboot will be when the rotating light turns off.
Hope this helps
Al

Nothing fancy
 

Posted by Andy Baker at 2/6/2001 11:23 PM EST


Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.


In Reply to: How often do you change batteries?
Posted by Joe Ross on 2/6/2001 12:45 PM EST:



During practices and regular driving, we just change it when it dies.

BUT, here's how we did it during competitions:

Andy: Kit, how new is that battery?

Kit: Um... not sure. I think Kyle changed it before the last match.

Andy: Do we have a fresh one ready?

Kit: Yeah... I say we change it.

Andy: I'm with ya.

Kyle: (just entering the conversation) Hey, gimme a fresh battery, the one on the robot might've run a whole 2.5 minutes... we gotta change it!!!!!!

Something like that. Come by our pit and you can see this process in action. :)

Andy B.