Batteries on robot

[Max Brin]

Can we use 2 batteries on the robot?
Do we have to buy exacly the same batteries as supplied with our kit?

Thanks & Good luck!

[Pat Fairbank]

You can own as many spare batteries as you want, as long as they are the same part as in the kit, but you can only have one at a time on the robot.

[Elgin Clock]

Originally Posted by Pat Fairbank

You can own as many spare batteries as you want, as long as they are the same part as in the kit, but you can only have one at a time on the robot.

One is incorrect.

At any given time while competing, One 12v main battery & One 7.2v backup battery that plugs directly to the RC. 2 batteries, different Voltages.

You may buy more batteries to have on hand, but they must be of the same specifications of the supplied KOP batteries.

Ie: no 9v batteries on your robot powering anything "functional".

The only exception to this rule (and someone correct me if it changed since last year) is the use of a battery to power a non-functional decoration.

I could be wrong about that last part though... Check the Manual, under Robot, and the Electrical section of that.

[Vince lau]

<R51> The only legal main source of electrical energy on the robot is one of the two 12v DC non-spillable lead
acid batteries provided in the Kit of Parts, or a spare of the same part number. The 7.2v “backup” battery is
considered an integral part of the Robot Controller, and may not be used for any other purpose. The only 12V
battery that may be used on your robot during competition (Friday and Saturday) is the Exide model EX18-
12. (Additional EX18-12 batteries may be purchased through your local Exide supplier.) You may use other
equivalent 12V batteries during Thursday practice rounds.

[Rick Thornbro]

Just out of curiosity, why would you want to use a second battery? They weigh 10-13 pounds a piece.

[Sscamatt]

Originally Posted by Rick Thornbro

Just out of curiosity, why would you want to use a second battery? They weigh 10-13 pounds a piece.

The battery isn't included in the weight of the robot.

[mechanicalbrain]

Originally Posted by Rick Thornbro

Just out of curiosity, why would you want to use a second battery? They weigh 10-13 pounds a piece.

Either to run things at higher voltage (Hard to do safely without frying things) or simply longer life. These robots chew up a heck of a lot of power. It's not unheard of for robots to completely drain a battery in a single game!

[Bharat Nain]

Originally Posted by Elgin Clock

One is incorrect.

At any given time while competing, One 12v main battery & One 7.2v backup battery that plugs directly to the RC. 2 batteries, different Voltages.

You may buy more batteries to have on hand, but they must be of the same specifications of the supplied KOP batteries.

Ie: no 9v batteries on your robot powering anything "functional".

The only exception to this rule (and someone correct me if it changed since last year) is the use of a battery to power a non-functional decoration.

I could be wrong about that last part though... Check the Manual, under Robot, and the Electrical section of that.

The 7.2 volts backup battery is technically considered as a part of the control system. Therefore, it is not considered a battery at all at inspections. And no, you may not have more than one of those on your robot at a time.

Conclusion: You can run your robot/have only one 12v and one 7.2v battery at a time.

[Al Skierkiewicz]

Originally Posted by mechanicalbrain

Either to run things at higher voltage (Hard to do safely without frying things) or simply longer life. These robots chew up a heck of a lot of power. It's not unheard of for robots to completely drain a battery in a single game!

Just to add to this post (even though it has been discussed ad nauseum before) it is true that some teams drain a battery in one match. Unfortunately that points to an inefficient mechanical design. The battery for an efficient 120 lb robot design should last more than one match and many last three or four before needing a recharge. Even good designs can have some problems (loose bearings, axles out of alignment and extreme side loads on motors or transmissions) that eat battery. It is wise to check your current draw with a current meter (Amprobe or Ampclamp) to determine your running current draw. If it should be higher than previous testing, look for a mechanical problem.