By what you're saying, it seems there are teams out there using cardboard batteries during weigh in. :p
I don't think a team would get to the point to use a dummy battery, in the sense of a hollow one or something like that. What I have read here in the forums is that some teams use really old batteries for inspection, as it is a known fact that they actually get lighter with time. It is a cheap shot, nonetheless, but you can always blame it on the freshman member for putting it in place, in case you get caught. :rolleyes:

So, yes, I think the robot should be weighted without the battery in place, or at least some "official" one, standardized to every team.

I think the latter part of this quote is an excellent idea. Have one, brand new battery (or other consistant weight) at every regional event. You take your robot to the scale without the battery and this battery is placed on the scale with your robot (and everyone else's). The weight limit remains the same. How about that?

Oh, and don't try to place your toe under the scale and lift up while your robot is being weighed. They look for that too. (although it is helpful and okay to fudge with it a little up and down before the acutal reading is taken to ensure an accurate measurement.)

That may be a good idea. :D
Last year we were weighting the robot in Seattle and the scale would range from 130 to 130.5, so *someone* (was it me? :)) had the brilliant idea to empty the air tanks to see if it would help - heck, the air above us weights a whole lot :D .
Well, the scale actually went half a pound up... Go figure
"And the robot got some nice speed holes..."

I must admit...
 

If we were close at weigh in, we would weigh all of our available current year batteries and choose the lightest one. This helped us a little and also fell well within the spirit of GP and FIRST.

Why not simplify a little bit and just figure out the average battery weight and subtract it from the total allowed weight, and allow teams to weigh in without the battery? Net result should be the same...

For example, if the official battery is deemed to weigh 14 pounds, just make the weight limit 116 pounds, and have everyone weigh in w/o the battery.

The "official battery" idea would also help to check the "is the battery easily removed" item from the inspection, plus, 130 is a nice round number to play with, eh? :D

It's pretty easy to tell just by looking at the battery compartment on a robot if it's easily removed. However, an "official battery" won't really solve any problems - when you have 4 or more weigh-ins occuring at the same time (some regionals have 2+ scales, the Championship has at least 4 scales), you'd need 4 "official" batteries. And guess what? It would be very likely that there'd be minor variations between the 4.

In that regard, the scales at the Championship seemed to vary by up to 1/2 pound anyway, so there's already a lot of "slop" in the whole weigh-in process. I don't have a problem with people weighing in with the lightest battery they have (as long as it's still a legal battery). There's no rule against it and it only gains them a marginal amount of weight anyway. If there really are teams that would stoop so low as to weigh in with a hollowed out battery, then those teams will find a way to cheat one way or another, making this somewhat of a moot point.

I think we should weigh in without the battery and change the weight limit to 55 kg.

Batteries
 

I would say without or at least FIRST should have a 'Standard' battery weight. We used 8 batteries last year and the difference between the lightest and heaviest was almost 1 lb.

DET
Team 343

Re: I must admit...
 

I think many teams did this exact thing. Using a "lighter, Real Battery" is much different than a "dummy". It's completely legit but at the same time unfair to those teams who get stuck with the heavier batteries.
I have seen a ~2lb difference (12.2lb - 14lb) between some batteries. 2lb's is a lot of speed holes if you don't have the "right" battery to weigh in with.

My suggestion:

Rule: Battery must be easily removed in under 15 seconds.

Reasons:
1) Very few designs have broken that
2) Easy for battery removal weigh in after Systems check.

Team shows up, does all the tests (lights, air, etc.), then gets timed for battery removal, then weighs in without putting the battery back in.

This alleviates the 'dummy battery' problem, battery weight flux problem, and gives grounds for "changing" weight limit. Be it, "lower" to 120lbs [no bat] or "keep" at 130. (Keep in mind 12-14lbs + for battery when on field)

battery
 

The weight of exact same year, same model batteries will vary from 13.5 to 14.2.

I have heard of some rookie teams that weigh in with a "Dead" battery to save weight. That is what the veteran teams tell them to do.:yikes:

If any of you remember when we moved from the drill batteries to the current batteries the weight limit was increased 10lbs to be able to keep the weight limit the same. So there is no real reason to change the weight limit or weigh in without a battery.

Re: Batteries
 

As I understand the rules, that would be illegal, since you were only allowed to compete with the two 2003 batteries that were provided in the kit, irregardless of how many 2003 batteries you may have bought.

P.S. If you get to weigh in without the battery, people will just add 10 lbs more stuff on their robots, and the point is defeated.

Cory

Re: Re: Batteries
 

No.. the POINT of weighing without the batteries is for equality. As has been stated by a few people, not every battery has the same weight.

130lbs = 130lbs with battery.
130lbs with battery = 116-117 lbs of materals + 13-14 lbs battery.

Has your team ever had to make speed holes to cut a 1/2 lb? Why do that when you can grab a different battery and problem is solved? That's what many teams do. Weigh in with a lighter battery, inspect at 130lbs, then go in to the field at 131 lbs.

1lb can make the difference between an assembly working and not working. I say.. make it fair for all.

Re: Re: Re: Batteries
 

Brandon, this is a very good point.
I guess I didn't really understand "what all the fuss was about" until you phrased it like this.

I wonder if FIRST has ever considered this?
It seems like a trivial issue, but there is a definite something to it.

John