The team has been prototyping our climber & we’re planning to have a discussion soon to make decisions for the final design. We’re looking at motor, gear ratio, winch drum diameter, etc. options as has been discussed on several Chief Delphi threads, and it seems like there are plenty of fine options depending on how fast you want to try to climb & whatever constraints you are dealing with.
One of the constraints I’m thinking about is the battery. Given all the driving cycles for gears and/or fuel, several motors spinning for intake-agitating-shooting, etc. what state are folks thinking the battery is going to be in when it comes to the last 30 seconds of the match? How much power, conservatively, do you think an average team can count on at that point?
I would think an exclusively gear bot will have used a lot less battery by the end of a match than a bot that has been collecting, agitating, and shooting balls, but I’m not sure how great the difference might be because I’m not that experienced.
If you have most of your robot assembled and you really want a semi-accurate estimate, you could always try using the test mode on the drive station. It has all the periods of the match set as default and you can work it as hard as you feel necessary or little as possible.
We played with auton programming off and on for most of the day today on our robot, and it didn’t run down the battery for a long long time…I’m hopeful. But we have a gear robot, so no ball stuff running all the time, just a little compressor, to be used as needed to pop gears onto the peg. Then climb with a single CIM at the end of the match, if it works right.
I think we’ll be ok. It was definitely a concern during the planning phase.
It depends…
About half of all teams are not designed for optimum efficiency in motor design and usage. It is not uncommon for teams using a lot of motors to draw down the battery during normal use to 7 volts or less under load. When that load is removed and a single motor is used at the end of a match, you might have enough for a climb. Please remember that the battery has an internal resistance that drops the battery voltage dependent on current. With no current, you will see near full battery voltage. However, as a battery is discharged the amount of available current and voltage goes down. I have seen many teams over the years getting battery readings in the 5 volt range at the end of a match under load.