Battery Charger Restrictions

[acrease77]

At the New York Regional, the judges told us that our battery charger, (DSR 8-Bank Digital Battery Charger, Model# INC812A) was not allowed in the pits and that we had to get rid of it. None of the people on the team have been able to find any rules restricting chargers in the manual, but the judges still insist we have to take it out of the pits because we may misuse it and mess up the batteries, even though the charger has basically the same ampage and volts and all that stuff as the KOP chargers, but despite our arguing the judges made us take the charger out of the pits and we had a freshman sit by the charger outside the arena and run back and forth with charged batteries. So what should we do? Are there rules about chargers we dont know about or should we still argue with the judges?

[imac256]

Next time this happens ask to see which rule they believe prohibits it. To my recollection there are no rules saying which charger you have to use, only which batteries you have to use.

[MagiChau]

To me it sounds more like a venue rule. I cannot say if this prohibition seems like it is unnecessary or not.

[acrease77]

We asked them that and we even brought them a printed copy of the manual, and i wasnt there cause i was in the stands but they said that it was unadvised or something like that, but I think that still doesn't justify because we were never told we weren't allowed certain battery chargers, so we should be able to keep it. And we didn't have any trouble with it in the week 1 New Jersey regional, so i'm not sure what to do.

[IndySam]

Judges told you that, are you sure?

More than likely it was the safety personal or the inspectors. Please clarify.

In the past there were rules against the type of charges you could use. Such as this from last year:

<R39> An automatic battery charger rated for a maximum of 6 amperes must be used to charge the ES17-12 batteries. When recharging the ES17-12 batteries, either the charger provided by FIRST or an automatic charger with an equivalent charging current rating may be used.


There is no such rule this year. If an inspector told you there was a restriction you need to point out to the head inspector that there is no such restriction this year.

[Ian Kaplan]

To me it sounds more like a venue rule. I cannot say if this prohibition seems like it is unnecessary or not.

I do not believe that was their claim. We were fine in New Jersey, but in New York they claimed that it was against FIRST's rules.

[Andy A.]

Do you happen to know for certain what the maximum charging current is?

It is possible to damage and even rupture this type of battery with excessive charging currents. This can be extraordinarily dangerous and, at a minimum, would result in a minor hazmat cleanup situation. You can imagine what the worse case scenario would be.

The manufacturer calls for a 2 amp charging current, for what it's worth. 6 amps is, through experience, safe but probably does the battery's lifespan no favors (oh well). Anything above 6 amps is considered dangerous. If the pit staff called your charger out it was either because

A: The maximum charging current was grossly in excess of 6 amps.

B: They felt that the maximum current draw of the charging station could overload the circuit it was connected to

C: They felt that the number of batteries, cables, and such in close proximity merited a safety hazard of its own.

Most of this is subjective (and my list isn't at all all inclusive) and in the end the pit staff and venue staff get broad authority if they feel they are acting to protect the safety of teams, public and venue. I'd guess they made a call along the lines of C. Maybe not fair, but without being there I couldn't fairly say. You handled it correctly though, so good on you and your team. I would suggest that, if you plan on attending another event this year you email the event coordinator to discuss the matter ahead of time. He/she can involve the necessary pit personal so, come game day, there is no confusion.

[1986titans]

According to a quick Google search on the battery charger specified in the first post, it can charge at 2, 8, or 12 amps. Those last two don't sound too good for the batteries.

[Ian Kaplan]

Do you happen to know for certain what the maximum charging current is?

It is possible to damage and even rupture this type of battery with excessive charging currents. This can be extraordinarily dangerous and, at a minimum, would result in a minor hazmat cleanup situation. You can imagine what the worse case scenario would be.

The manufacturer calls for a 2 amp charging current, for what it's worth. 6 amps is, through experience, safe but probably does the battery's lifespan no favors (oh well). Anything above 6 amps is considered dangerous. If the pit staff called your charger out it was either because

A: The maximum charging current was grossly in excess of 6 amps.

B: They felt that the maximum current draw of the charging station could overload the circuit it was connected to

C: They felt that the number of batteries, cables, and such in close proximity merited a safety hazard of its own.

Most of this is subjective (and my list isn't at all all inclusive) and in the end the pit staff and venue staff get broad authority if they feel they are acting to protect the safety of teams, public and venue. I'd guess they made a call along the lines of C. Maybe not fair, but without being there I couldn't fairly say. You handled it correctly though, so good on you and your team. I would suggest that, if you plan on attending another event this year you email the event coordinator to discuss the matter ahead of time. He/she can involve the necessary pit personal so, come game day, there is no confusion.

While I will let someone on my team talk about the specs of the charger, I can say that we used this charger at the New Jersey Regional with no problems.

[Tristan Lall]

As mentioned above, it's unlikely that a judge (they wear blue FIRST shirts) told you that. If you tell us what sort of shirt (colour and style) the volunteer was wearing, we can probably tell you what their responsibility was.

If it was a venue restriction, someone should have said so, in advance if at all possible. (I doubt it was actually a venue restriction.)

And no, there's no battery charger rule this year. (It used to be in "The Robot", which I always figured was a mistake—it belonged in "At The Events", unless the intention was to prohibit robots from using improperly-charged batteries, a prohibition which was never articulated in the old rule.)

[ebarker]

The charge rate issue has been covered in other threads with a post here on the max rates.

http://www.chiefdelphi.com/forums/showpost.php?p=1027964&postcount=4

The Schumacher looks like a nice charger but the middle and high charge rates are not good for these batteries. At best it will shorten the life and worst cause a catastrophic failure and either way that is a lot of money burnt up in batteries.

[Andy A.]

While I will let someone on my team talk about the specs of the charger, I can say that we used this charger at the New Jersey Regional with no problems.

Just remember that what flies at one venue may not go over well at another. This is as old as FIRST (or, as old as multiple venue FIRST). The folks who were working at NJ probably aren't going to be at the same venue you are this week. And, as an aside, one of the least effective arguments in these sorts of debates with on site staff is "well, it was ok at X regional..."

They may well be wrong, and at a minimum should have articulated clearly what the issue and their thinking was. If that didn't happen, then yeah, there is a valid issue that should be discussed and resolved so everyone can make a better call in the future.

I did look up the specs on the charger model listed in the OP. The specs are a little confusing, but from what I can tell it has three charging rates- 12, 8 and 2 amps. Of those, only the lowest setting would be safe and, in previous years, legal. Whats worse is the product brochure makes it sound like this is entirely automatic and not user controllable (though I find that hard to believe). While there is no rule this year stating you can't use higher charge rates, I would agree with any FIRST personal who requested that you not exceed 6 amps. If you couldn't make sure the charger stayed below 6 amps then having you remove it from the pits would be defensible in my mind. Some teams may be comfortable with a higher charge rate, but I really don't believe it's worth it.

I found the product manual at http://www.northerntool.com/downloads/manuals/167821.pdf . Let me know if that isn't actually the same model you have.

[ChrisH]

For future reference, when in conflict with an authority such as the Chief Inspector (volunteer shirt and vest) or Head Safety Judge (green polo shirt) over a rules issue, the proper person to talk to is the FTA. He or she probably has more credibility with the official and is a neutral party in the dispute. They also have access to a complete and up to date copy of the rules to assist in sorting things out.They can also involve the GDC if needed, though I have never personally heard of it being necessary.

While the FTA is mostly concerned with keeping the field running and robots talking, this sort of thing is also part of their job.