2010 nationals

because everyone's scared!! haha lithium ions will do the same thing. the only difference between a "li-ion" pack and a "lipo" pack, aside from the foil vs. can thing, is safety precautions. each li-ion cell has a resettable relay, and the lipos don't. I'm trying to figure out how to approach NRL, asking what the real deal is, suggesting that it isn't that bad despite my history with batteries..

im sure your exactly who you want to hear from

yup.. lol just digging myself a bigger hole, thats all.

don't forget, I had problems with A123's when they first were allowed! now, they didn't catch fire, but the robot quit, and you guys trashed it!

Many competitions are not allowing them because of the insurance they are carrying and where the event is being held with their insurance.

Lipo pack are just not safe with the current technology and chemistry. Every team continues to push the limits of how much voltage and current their robot can handle. This causes the batteries to be pushed way beyond their intended discharge rate. Although Lipos today are much safer than they were just 2 years ago, they have not been perfected yet.

The NRL used to allow Lipo's a few years back, but they decided to change their mind when a few of the packs decided to fire up and make an educational competition some what dangerous. This can happen with basically any battery pack, but is more potentially hazardous with Lipos.

Last year, BBIQ "formally" announced that they would allow Lipos to be used just 9 days before the San Fran tournament as long as they meet certain requirements and they used a charging sac. This is just one more case where Miami is given different information than every other team "outside of Florida". When I called Jose to question the change he said they decided to make the change since there were just one or two teams that had designed their robot around Lipos and they wanted to make sure they could compete. These are the words Jose used, "there are a couple robots from Miami that designed their robots around Lipos since they were allowed to use them in their competitions down there. Since these robots really aren't that good, and won't affect the final outcome so we decided to let them use Lipos."

I guess this means Ransom only has robots that won't affect the final outcome...lol. I really don't think that is the case. They have always pushed the envelope at Ransom and I'm sure they will continue to do so in the future. Their designs push other teams to get better and thus the overall robot competition continues to gets better each year.

I think we can all agree that A123's are much safer than Lipos at the current time. A good example of how potentially dangerous Lipos can be is looking at the Motorama results this last year. They had numerous fires resulting from the use of Lipos. And these were the "pros", not students just learning how to put together a robot for the first time. Safety HAS to be looked at first to keep the competition safe for everyone. If we all use safe battery types, the playing field is level and we can all design around a safe environment which is educationally friendly.

I think that Moto is continuing to allow them, despite the incidents.

there are several conditions that need to be met

1) charging them needs to be monitored to prevent overcharging/too fast charging and in a sac

2) the garbage pail, sand, a snatch pole and proper extinguisher seems to make an almost non-issue of in the arena incidents

3) Perhaps a bit more training is needed, including inspection and discarding of puffy cels.

4) as mentioned earlier, a properly sized circuit breaker could go a long way.

motorama is still allowing them so far but your not allowed to use them at FI anymore
maybe a matter of time till motorama

Once you have to design around 123's everyone will go that way... my guess is that after FI and the museum competitions this year, they will all be 123's.

Robogames allows them and doesn't look like they are moving backwards any time soon

Many teams in Miami don't really want to move backwards either.

So, maybe there won't be a TRUE national competition for a while....even if there are 2000 bots from the north east at the event in KC, it could still be considered a local or regional event, if there isn't decent representation from all corners of the country.

so a its only "national" competition because it allows lipos?!
that might be one of the stupidest things I've heard.

whoever ends up with a better run program with a stronger showing of bots will end up the actual national competition regardless of the batteries allowed.
I think NRL moving its national competition to a central location at the SkillsUSA is a big step forward.

I gotta thank you, Marshall, for your comment about Ransom 'pushing the envelope.' I've thought of your team, and the Titanium Knights in that way for a long time now, but never considered Ransom in that same category. I guess having Will around has upped our rep!

LiPo's can be managed, and the tech is improving, but I'm not surprised to hear some competitions disallow them--I suspect eventually they all will accept these as a sort of 'gold standard' in terms of power density, but with that comes the price of instability.

Sorry to hear that, yet again, the communication breakdown (Ha!--Led Zep rulz) has unfairly favored Miami teams. When and if my team wins, I want it to be because we did things better (or maybe just got lucky) not because other teams didn't 'get the memo'.

This year, Ransom has standardized all our robots on LiPos. (And with the exception of the 120, which is using Magmotors, and one of the 15's, they are all running brushless weapon motors)

On a related note--has anyone used the Castle Phoenix Ice Lite ESC yet?--I just tried one out today and I think it is AWESOME!! Really detailed programming settings, and DATA LOGGING (Sorry for the all caps, but I'm excited) It can record like ten different things (voltage, current, throttle signal, estimated rpm, power, cumulative mAh, Battery ripple, etc.) at 10 datapoints a second for over 7 minutes. With one of these, (and some time and knowledge) you can actually optimize a drive system. Just wait till next year

Cody Harris wrote:

so a its only "national" competition because it allows lipos?!
that might be one of the stupidest things I've heard.

or maybe another mis-read?

It's only a national event if enough teams from around the country attend, not just local teams....and I believe that you agree with me on this?

My point concerning Lipos, is that robogames (which may be the only national/actually international event that seems sure to happen) allows lipos.

So, I guess we have to ask why this is the case....?

1) Are there not a lot more RC cars and airplanes using lipos...than combat robots?

2) Is it the bad rep they have due to incidents such as the fluffy fire?

3) Is it that some events have a better handle than others in dealing with the potential problems?

I guess that I just don't like to see technology potentially moving backwards.

On a side note, I have been speaking with some others about all this and some good ideas have emerged.

1) It has been recommended that any team using Lipos, should be responsible for bringing the necessary equipment to deal with the potential hazards.

This would include possibly a steel container, sand, suitable extinguishers, and handling equipment, etc.

2) Everyone should be trained to deal with any and all potential incidents.

3) teams should also be responsible for proper sizong of components, especially with repsect to esc and battery capacity.

4) as mentioned elsewhere, I've seen esc's catch fire even without lipo batteries. None of the mamba esc's have provisons to limit current draw. If a weapon jams and tries to draw more current than the esc can provide, and if the battery pack can provide this, then a fire can occur.

I also agree with Will, that circuit breakers might be a good answer to this.

Any thoughts...anyone?

I do agree with what you said when you put it that way.
I also like your idea that teams using lipos NEED to be able to control them.
My biggest thing is having the right fire extinguisher.

Also the venue of the competition has to be kept in mind.
A farm complex or even a convention center keep it at a entirely different problem.

then again, eo's need to understand that they are not running a barbie fashion show, it's more like a dirt bike race or whatever....

So, while an open area at the center of a mall might be FREE, it also might not be the best place to hold an event where fires WILL always be a possible occurance, lipos or not.

I just got off the phone with Castle and they have no solution, no current limiting, and claim that no other esc brands have a solution either.

I'll bet that even in KC, if a bot goes on fire due to esc overload, and it fills the area with smoke and fumes...then the anti-lipo crowd will be scratching their heads and it could possibly be the end of events at that location, if not elsewhere as well. I hope that this doen't happen and that in any case they are prepared to deal with any fire potential

but there is a HUGE difference between a esc fire and a lipo fire.
Esc fires are short they burn up quick and can be extinguished with a normal ABC fire extinguisher
Lipos emit a toxic fume.
Another one to add to the list of saftey reasons

I'm willing to bet ESCs produce plenty of toxic fumes of their own when they burn, but I'll definitely agree most lipos make more of it.

I think competitions that don't allow lipos should find a way to allow them. If that means finding a way to properly ventilate small arenas or set up procedures for safe charging areas, so be it. If I feel comfortable with a phone powered by a lipo sitting dangerously close to my crotch on a daily basis, they should feel comfortable making a competition that permits robots running on lipos.

most phones are li-ion batteries
so is my laptop battery

thanks for the compliment Marshall, but you guys have pushed more teams than we have!

not to get into an argument about cell chemistry and packaging, but phone batteries ARE lipos. Lipos are actually Lithium ion polymer batteries, still lithium ions, just a sub-catagory. Iphones have lipos in them, they don't ban those from competitions.. or planes..

I think we can all agree that Lipos are potentially more dangerous than Lithium Ion, NiCad, NiMh or plain old Pb gel cells... yes there are a few teams that are still using them…lol.

In addition, we are an EDUCATIONAL group of robot enthusiasts. This means we are going to have students that may have never used a screw driver or may have never opened up a computer case to see what is actually inside. Those that have been part of this forum are the exception to the rule. We have tried things and have sometimes learned the hard way that BAD things can happen when you least expect it.

A good example, last year one of my best kids plugged in our A123 battery packs and happened to misconnect the leads. Normally we have everything color coded, but he was using a back up pack for the safety inspection. That pack had been color coded to connect in series with a different wiring set up. When he activated the switch, smoke started pouring out of the robot. Thank God he had the smarts to flip the switch and pull the leads as quick as he did... total time was 3 seconds at most. But if that happened to one of my less experienced students, it could have been a full robot in flames.

I was also there when Carnegie Melon's full body spinner sparked up and was a complete fire ball. Those were college students with the smarts to deal with the situation. In both cases, it could have been so much worse had either of these teams used Lipos instead if Lithium Ion and NiHh.

It is all about safety... What would happen if this occurred in a school van, hotel room, or during the evening when the pits are normally empty? The RC industry uses Lipos in their vehicles, but they are only powering ONE motor, either brushed or brushless. Their entire car weighs less than some of our weapons... lol. They are not experiencing the current drains we have exposed these batteries to… We are pushing all the limits and thus we are exposing ourselves and others to dangers we don’t have to. Safety… that is what is most important in an educational event.

I hate to diverge from this talk of Lipos but i have a slight problem, my advisor has suddenly canceled our trip with out warning he says we can go by ourselves if we want but he just isn't coming. there are no other staff members willing to chaperone so we will have to get there privately. This is not good. I don't even know if we can compete without our advisor, how old must a supervisor be to allow students 17 & under into the pits at nats. I dont even know if we can still ship this thing because of the short notice. I need help here any suggestions would be appreciated.

if a parent is going, you're golden. otherwise, I would suggest you adopt someone from down here. Nola definitely won't mind. In fact, she'll think it's awesome you came anyway. I can help you out probably. text me : 305-746-5251

oh yeah, if you need a place to ship to, my house is always open!

what do u mean adopt someone? thanks for the offer i may need to take you up on that because ups cant get it there till thursday

jeeves

let me know if there is anything that I can do.....didn't you have arrangements for a van? who was supposed to drive?

Richard 954-680-2009