can we use 2 batteries?

[vivek16]

Only one battery may be used at one time. With 2 batteries in serial, you'll be getting twice the voltage (clearly an advantage although it may fry your controls). With them in parallel you get twice the current. Thats an advantage too.

If one of your batteries is for ballast and is not actually acting as a battery, I believe it is allowed.

[Russ Beavis]

No - you cannot use extra batteries for ballast. It doesn't matter what you're doing with the batteries but only 1 is allowed so you'd better use it for power.

Russ

[Pneumaticsman]

Ok thank you I just needed some clarification on that. I suppose it's a good thing we can use it as a ballast though cause we're gonna need the weight this year, we're buildin a pretty light bot this year

[Pneumaticsman]

Dang it now I read Russ Beavis' post that said you can't even use it as a ballast sad day

[MrForbes]

We have a box of pennies at home that weighs 27 lbs....but, how to secure them?

[jtdowney]

Last year in the finals at GLR, Mr. Smith from Truck Town lent 1646 a vice grip that we attached to the robot to offset the weight we lost without our arm.

[Rick TYler]

Originally Posted by squirrel

We have a box of pennies at home that weighs 27 lbs....but, how to secure them?

In a gallon milk jug full of polyester casting resin?

[gorillamonky]

Originally Posted by squirrel

We have a box of pennies at home that weighs 27 lbs....but, how to secure them?

wouldn't that render the pennies unusable?

ps, if they where shaking around, that would be really loud

[Al Skierkiewicz]

From Section 8 Rev E

<R01>
Energy used by FIRST Robotics Competition ROBOTS, (i.e., stored at the start of a MATCH), shall come only from the following sources:
A.
Electrical energy derived from the onboard 12V battery.

Please remember that anything used for ballast must be securely mounted to the robot frame. The intent as with any object on the robot is to provide the maximum safety for the participants including judges, refs, field reset people and other volunteers near the robot.

[Justin Stiltner]

388 has used actual gym weights bolted to the frame, and team 116 has a 27lb (I believe) block of lead.

[Al Skierkiewicz]

Originally Posted by Justin Stiltner

388 has used actual gym weights bolted to the frame, and team 116 has a 27lb (I believe) block of lead.

Please remember that lead has some nasty properties. If used, it should be sealed in some fashion, paint works well. Teams using lead ballast in the past were required to complete this step to prevent contamination. Please remember to protect team members when working with this substance as it is prepared for a firm mounting on your robot.

[MrForbes]

If we need ballast this year (current robot weight is 106) we were considering cutting up some 16 gage sheet steel, and screwing it to the bottom of the robot. It would be several pieces so weight could be adjusted easily if needed.

[Chris Fultz]

Originally Posted by squirrel

(current robot weight is 106)

Either you have forgotten something major, or you are my hero!

[MPG]

In 2007 we used an eight pound sledge hammer and a bunch of wrenches zip tied to the bottem of our robot to ad weight

[MrForbes]

Originally Posted by Chris Fultz

Either you have forgotten something major, or you are my hero!

Most of the robot was together and on the scale...honest!