Can someone post this on FIRST q/a

[ahecht]

Good question, as it never made sense that a 50 amp connector would be used when our circuit breaker is 120 amps. I'll include the obligatory link to 190's melted connector.

However, the SB120 is very large and heavy (it's about twice the size of the current FIRST conector, the SB50). You might want to go for something in between, such as the SBO or the SBE80.

[Joe Ross]

Originally Posted by ahecht

However, the SB120 is very large and heavy (it's about twice the size of the current FIRST conector, the SB50). You might want to go for something in between, such as the SBO or the SBE80.

Zan, we also used the SB120 last year, and yes it is larger and heavier, but not terribly so.

[Al Skierkiewicz]

Guys,
It wil be interesting how First responds to this question. The rules are not really clear in that they recommend the supplied connector as a minimum but indicate if you use something else you may not be compatible with other team's connectors. We use a Tyco/Amp connector that is available from Newark. It is designed for 100 amps, works well with #6 wire and looks like a larger version of the Anderson power pole connectors. We have used these for several years now. Remember to add mating connectors to your battery charger.

[Specialagentjim]

Originally Posted by Al Skierkiewicz

Guys,
The rules are not really clear in that they recommend the supplied connector as a minimum but indicate if you use something else you may not be compatible with other team's connectors.

We use the supplied connector every year and it's proven to be helpful during finals. When it gets down to that finals crunch, you want to have good charged batteries, and often times you run clean out. Luckily, sometimes you'll have an alliance that brings 20 batteries and has some amazing charging system devised. You borrow a battery from them for the match. Thats our thinking at least.

[DanL]

Originally Posted by Specialagentjim

We use the supplied connector every year and it's proven to be helpful during finals. When it gets down to that finals crunch, you want to have good charged batteries, and often times you run clean out. Luckily, sometimes you'll have an alliance that brings 20 batteries and has some amazing charging system devised. You borrow a battery from them for the match. Thats our thinking at least.

This topic has been brought up in a quite a few threads. In one of them, it was said that you can make a simple adapter with the kit connector on one end and your connector on the other.

[Venkatesh]

When we read the rules, we never got the idea that other connectors of different ratings were permitted. So, we were thinking of using two in parallel, mounting them in such a way that they would act as one unit.

If this would be allowed, it would be a great help.

[Al Skierkiewicz]

Originally Posted by Venkatesh

When we read the rules, we never got the idea that other connectors of different ratings were permitted. So, we were thinking of using two in parallel, mounting them in such a way that they would act as one unit.

If this would be allowed, it would be a great help.

That is actually a great way to double up the capability. The downside is the added weight. Make sure everything is tight and well insulated. I would like to see it if we are at a comp together. Come and find me if you can.

[Greg McCoy]

That would ensure compatibility with other team's batteries too. Good Idea!

[Joe Ross]

Well, FIRST answered no on the different battery connectors issue. The full response:

Section: 5.2.6 Status: Answered Date Answered: 2/12/2004
Q: <R20> May we use a different Quick Disconnect connector for the battery than the one provided in the kit? Specifically, we would like to use the Anderson Power Products SB120 (the next size up from the ones in the kit).

A: No. Use tie wrap to hold provided connector together.

Do you think they misunderstood the question, or do you think the ruling is no different battery connectors?

Venkatesh, you should probably ask about your method.

[ngreen]

Originally Posted by Specialagentjim

We use the supplied connector every year and it's proven to be helpful during finals. When it gets down to that finals crunch, you want to have good charged batteries, and often times you run clean out. Luckily, sometimes you'll have an alliance that brings 20 batteries and has some amazing charging system devised. You borrow a battery from them for the match. Thats our thinking at least.

Honestly, I am very wary about borrowing batteries from other teams after last year. We borrowed a battery from a local team for national and we ended up not moving one match because of a dead cell. That hurt us tremendously since it was in qualification. We ended up seeding like fourth or fifth but without a bad cell we could have easily been 1st. And you remember the number 1 alliance from Archimedes (wildstang, las guerillas, husky brigade). So I wouldn't completely trust a borrowed battery make sure you test it before, because when you're not moving, a minute and 45 second is a long time.

[Al Skierkiewicz]

This is a vast difference in policy from previous years. The rules specify "a" quick connect not "the" quick connect. Standby for further info.
We currently have 8-10 batteries, several chargers, four past year's robots and a prototype and robot from this year all wired for a different connector.

[Aidan F. Browne]

Al --

Please read the whole rule. The intent is that the connector provided in the kit is the connector that must be used. This is not an error.

"<R20> The 12v battery must be wired directly to a quick connect / disconnect connector (provided in the kit)"

As you can see, the rule clearly states that the connector is provided in the kit. The reason that the word "a" was used, is that there are two of the connectors provided (the entire connector is made up of two mirror-image halves).

Sorry to hear that all your previous equipment uses a different connector - but for 2004 the rule has changed.



Aidan

[Dave Flowerday]

Originally Posted by Aidan F. Browne

Sorry to hear that all your previous equipment uses a different connector - but for 2004 the rule has changed.

Do you happen to have any insight as to why the rule was changed? Using a different connector (assuming it's rated for at least the same amount of current as the provided one) does not cause any safety issues or add any unfair advantage that I can think of. This seems to fly in the face of the notion that the rules were going to be kept simple this year and that common sense should prevail. To me, this is like asking "Can we use #8 wire in place of #10?" and being told "no".

Rules like this would be a lot easier to accept if there was at least an attempt made at providing a reason.

Additionally, I read the passage from the manual that you quoted as "You need to use a quick disconnect, and there happens to be one provided in the kit." I don't read it as implying that it's required to use the one in the kit, but apparently that's what it meant.

[Venkatesh]

Could someone post a question related to my method on FIRST's Q&A? I won't have the ability to post that question for some time.

[Al Skierkiewicz]

Originally Posted by Aidan F. Browne

Al --

Please read the whole rule. The intent is that the connector provided in the kit is the connector that must be used. This is not an error.

"<R20> The 12v battery must be wired directly to a quick connect / disconnect connector (provided in the kit)"

Aidan,
I must disagree. The wording is not very clear but implying that the word "a" is meant to identify one half of a connector is a stretch. The phrase in parenthesis implies a suitable connector is included other wise it would read without parents. Although the wording of this rule has changed from last year, it's implication for veteran teams is that equivalent or better substitutes are allowable. I know that I read in the Q&A recently, a similar question was answered that FIRST recommended using the supplied connector and if a team used something different they risked incompatability with other teams should the need to share batteries arise. That question appears to have been removed from the Q&A as I was not able to find it this afternoon. Realistically, today's answer seems oddly worded in that the question seemed related to the connectors popping apart not replacing a kit part with something better.
I agree and it has been my stated opinion that the Anderson Power Products connectors work fine for most teams. There are teams that draw excessive amounts of current during match play that would result in heating, and fire using the 50 amp connector. A rule of thumb is any team that uses most or all of the motors including both drills combined with both Chips and/or both FP's will draw more current than the supplied connector can handle. You and I both know that the stall current on any one of these motors is over 100 amps.