MK 12 volt battery question

[Seki]

They said that we could ONLY use the MK 12 volt battery as our maing power battery, aren't they the same as last years batteries? the previous years batteries are 12 volt, can we still use them?

anyone know?

-Thanks

[bear24rw]

The batteries are slightly different from those last year. I'm not sure of exact specs. You are not aloud to use batteries from last year as this would create an unfair advantage to those teams who dont have those batteries from last year

[John Gutmann]

Originally Posted by Seki

They said that we could ONLY use the MK 12 volt battery as our maing power battery, aren't they the same as last years batteries? the previous years batteries are 12 volt, can we still use them?

anyone know?

-Thanks

It is not the voltage of the battery that is different. It is the model number. If you would go look at your batteries from previous years you would notice the are exide ES-xxx* model number. EX-xxx* != MK 12

-John

*I do not know the exact model number off hand.

[Richard Wallace]

Specs for the 2007 battery are here.

Specs for the 2006 battery are here.

The new one appears to have about 10% less stated capacity at 1C discharge rate. So if you could use the older battery you might get an advantage over a team using the new one -- which is almost certainly the reason why the older ones are not allowed this year. For more, see this post.

[VEN]

You are not aloud to use batteries from last year as this would create an unfair advantage

And it is definetly fair to all of a sudden make the batteries from previous years extinct in order to make the teams who collected their batteries from previous years and who can't afford to buy 10 extra batteries like other teams go through all the trouble of possibly losing qaulifiers due to the fact that the batteries don't charge fast enough.

Sadly there's nothing we can do about that. Might as well learn to deal with it. Big disappointment but oh well.

[John Gutmann]

Not every team is going to be in a match at the same time. We do know how to share.

[Kevin Sevcik]

Originally Posted by VEN

And it is definetly fair to all of a sudden make the batteries from previous years extinct in order to make the teams who collected their batteries from previous years and who can't afford to buy 10 extra batteries like other teams go through all the trouble of possibly losing qaulifiers due to the fact that the batteries don't charge fast enough.

Sadly there's nothing we can do about that. Might as well learn to deal with it. Big disappointment but oh well.

Everyone's in the same boat. Everyone has only 2 batteries and no collected batteries from previous years. That is, in fact, MORE fair than everyone but rookies having a collection of batteries from prior years. You can still use old batteries for testing and practice day. You have more chargers than the rookies. With even a little bit of effort on your part to solving the problem you could make 2 batteries work just fine for a regional. If you buy just one extra battery you should be more than covered. They can be had for around $50.

I speak from experience by the way. 57 takes just 3 batteries anywhere we travel and we don't have any problems.

[DanDon]

Originally Posted by Kevin Sevcik

Everyone's in the same boat. Everyone has only 2 batteries and no collected batteries from previous years. That is, in fact, MORE fair than everyone but rookies having a collection of batteries from prior years. You can still use old batteries for testing and practice day. You have more chargers than the rookies. With even a little bit of effort on your part to solving the problem you could make 2 batteries work just fine for a regional. If you buy just one extra battery you should be more than covered. They can be had for around $50.

I speak from experience by the way. 57 takes just 3 batteries anywhere we travel and we don't have any problems.

One of the bullets in <R46> says:

Originally Posted by 2007 FRC Manual

Items specifically PROHIBITED from use include: Batteries different from, or in addition to, those provided in the Kit Of Parts.

I interperet that to say that we can only use the 2 batteries provided in the kit. Opinions?

[Eldarion]

If that is FIRST's intention, I don't think it could be enforced. (How would FIRST know if a team brought more than two batteries to the regional?)

That said, I wonder if that is a mistake in the manual.

[Ricky Q.]

That rule was the same last year as well. You will be able to buy more of the same battery and use them, as long as they are the same as the ones in the KOP.

Expect a clarification in the Q&A or a Team Update.

[robind]

Originally Posted by dhoizner

One of the bullets in <R46> says:



I interperet that to say that we can only use the 2 batteries provided in the kit. Opinions?

No. I would interpret that to mean we can't use a battery in the kit, and another battery not in the kit at the same time on the robot.

[ntroup]

I would interpret this:

<R53> The only legal main source of electrical energy on the ROBOT during the competition is the
12VDC non-spillable lead acid battery provided in the 2007 Kit Of Parts. That 12V battery is
the MK Battery, ES17-12. Additional batteries may be purchased through a local MK
Battery supplier.

To mean that we can purchase additional batteries, and therefore, use them in competition, as long as they are MK ES17-12s.

-Nate

[Kevin Sevcik]

Agreed. R46 covers what you can use ON the robot at any time. No using 2 batteries at once, no using a different battery on the robot. Doesn't cover what you can have at the comp. So I would expect some Q&As but no updates on that.

[nparikh]

Don't know if anyone has noticed this, but the new batteries seem a bit heavier as well. We pulled out the scale today and clocked them at about 13.5lbs, which is about 1.5 lbs more than the old batteries (someone correct me if I'm wrong that the old ones weighed 12lbs)

[Karthik]

Originally Posted by Richard

Specs for the 2007 battery are here.

Specs for the 2006 battery are here.

The new one appears to have about 10% less stated capacity at 1C discharge rate. So if you could use the older battery you might get an advantage over a team using the new one -- which is almost certainly the reason why the older ones are not allowed this year. For more, see this post.

Richard,

There are some major differences between the two sections of spec sheets you posted.

Originally Posted by ES17-12 Spec Sheet, Top Section

Maximum discharge current (A) 5 sec: 90

Originally Posted by ES17-12 Spec Sheet, Bottom Section

Maximum Discharge Current for 5 seconds: 720 A

That's a huge difference. The Exide battery from 2006 had a 230A max discharge. Can anyone confirm which of these is right? Am I missing something here? If the max discharge has dropped all the way to 90A, we'll definitely be reconsidering our motor usage.