Power Management Recommendation for driver stations

At the 2010 Peachtree Regional the teams that played Saturday afternoon essentially had to play the afternoon on whatever charge existed on their Classmate. It was rough on the classmate battery.

When teams are at the driver station the classmate has to be running on its internal battery only !!

I would STRONGLY suggest that you get a dc-ac inverter, 100 watts or so. You can buy them at Walmart or a truck stop for $ 20 or so. Put an Anderson powerpole connector on it and plug it into a robot battery. Put the battery/invertor combo on your robot cart and it can keep the classmate topped off and ready for your match.

Then as you sit in queue Saturday afternoon you will topping off the classmate and be in great shape with the driver station. When you go to place the DS for the match you just pull the plug on the classmate and go to work.

It will cost less than a second classmate battery and you can use it as a power source for driver stations for public demos and to do a hundred other things.

one of the mentors from our team brought a portable laptop charger, and it worked phenomenally!
it was kinda like what you are suggesting, but in a light, conviniently small package. it weighed no more then 3 pounds, and was about the size of a letter envelope, and about a half an inch thick. it powered the laptop for the entire day whenever the laptop was not in the pits, and it still had charge to spare at the end of the day! (it is also re-chargable itself, so its uses are unlimited)
our classmate battery never dropped below green!
it definitely saved our butts in the finals.
I was happy we had it when I walked around and saw red battery indicators on some of the other teams’ screens…

If I knew the model number or anything, I would tell you, but I don’t.
Maybe Ill ask our mentor at the next meeting, and post it here. the thing was a lifesaver!

we talked to the head ref, and he said that it was legal to keep it plugged in durring a match, so the laptop did not go into power-conserve mode.
It seemed to speed up our camera-image speed a bit.

It helps to turn the wifi off.

Yeah, our team was feeling a bit of “red” so to speak on Friday afternoon.

We’re currently looking forward to doing something to aid in keeping the Classmate alive for matches. What has been said here is great, specifics would be fantastic.

I still wonder why they didn’t have a power cable on the alliance station - just to make things a bit less crazy for set up and stuff? Having a DS with a battery is nice, but some days its nice to have a power source.


Do you have any specifics on this device? Sounds interesting. I am currently designing/building a similar device. Would there be any interest for this?

What we did was just close the classmate after every match, bring it back to the pits and let it charge. Any time we were not on the field, it was charging in the pits. For eliminations, we went to the 3rd match of the semis, and we had plenty of battery left. The key is to leave it on the charger, and to close it after every match (it goes to sleep).

I do not know anything about it right now.
now that I think about it, the mentor who it belonged to is going away on a week-long buisiness trip tonight, so I will not know anything about the device for a while :expressionless:
I will try and let people know what it is as soon as possible!

the most I could tell you about it now is pretty much that it was a rounded-edged black box with about a 5" cable coming off of it. haha

Power was a bit of a problem for us as well. The matches drained power faster than we could build it between matches. By the end of Friday the battery was almost dead. At least emergency charging is available during eliminations.

Make sure you leave your classmate charging overnight at competition. It’s the only reason we survived Saturday

I’m a big fan of invertors / Anderson connector / robot battery arrangements because it give you a pool of batteries that interchanges with the robots and allows you do do all sorts of things.

Kinda like the military ‘one fuel’ concept. They have jets, helicopters, tanks, humvees, trucks, and motorcycles that run off the same fuel.

I wonder why FIRST couldn’t add power cables for the Classmate. I would see it as a very cheap solution. FIRST should get feedback about this because it does seem like a bit of a big problem that you can’t compete because the Classmate battery is dead.

Inertia - The trucks are loaded and rolling from regional to regional. Getting the solutions configured and shipped out and meeting the trucks at the next regional, implemented and rolled out to the next events I’m sure is an effort. And they are most certainly busy setting up for the CMP.

The cost of implementing the power cable solutions means that something else isn’t getting done. It is an economic opportunity cost problem.

Having the battery / invertor combo is great for demos. You can solve two problems at once.

We found that to be a HORRIBLE idea. Every time we would close our Classmate, the joysticks would get out of order, and often times it forced us to reboot the entire system.

Much better to just grab an extension cord and plug it in. (Bring some tape to secure it down better so robots can pass through if needed.)

The venue should be able to dig a few power drops out of their house box in a minute or two. All it requires is a threeway extension cord at each player station.

We also have a small inverter with connectors to a 12 v battery. We are using some of the older ones that we don’t want on a comp robot anymore.

We plugged in the laptop to this “charger” any time we were waiting in line.

Roger that, I copy your comments well !!

However I posed the question to someone in the know at the event and the answer was negative.

Who controls the field facilities ? The GDC ? FIRST engineering ?

The question needs to be asked because without consistent guidance from HQ there is going to be some confusion.

Our cart now has AC power on it so our alliance members can stay plugged in and charging during queueing. And we have a handheld AC kit for the opposing alliance so they can go ditto !!

When the teams move forward they can pull the plug and place their equipment onto the driver stations. All that doesn’t interfere with any understanding that FIRST has at this moment.

Should I post this to GDC Q&A ?

We just made sure our classmate was always plugged in between matches, and plugged in over night. (Don’t just power it off over night, the classmate phantom will suck down the battery anyway - no I’m not putting it in sleep mode.)


It really shouldn’t even take that long considering there already is AC power at the drivers station for the SCCF cases, as well as additional power drops for the fixed cameras on the corners of the field. I was surprised that FIRST didn’t provide the ability to plug the Classmate into power on the field. It will be interesting to see how these PCs hold up in Atlanta, and if any delays are caused by teams are waiting for the laptops to wake up or if they fail from the long walks or waits in the queue.

While we didn’t have any issues last weekend in San Diego with ours, there was a few rounds where our battery was dangerously low. Plugging it in when the bot was in the pit helped, but there really should be something on the field to plug them into. It’s very likely that the veteran teams will need to reuse PC next year, and who knows what shape the batteries will be in by then. Maybe someone will donate batteries for the KoP :rolleyes:

Just out of curiosity how long were the inverters staying running on one of the robot batteries? I had thought of doing this at some point on Friday but wasn’t sure how long of runtime you would get before you would need to recharge the batteries.

It is my understanding that each event is slightly different. Most often the local regional committee is the one paying for the venue and services it provides. I have never had a problem asking for additional power in the Inspection area. I am concerned about power cords running between robot carts while in the queue for obvious reasons. If someone had thought of this before, there should be power at the driver’s station for all robot control. The old IFI controllers were powered by the field when you plugged in.


If they are using the same field then I’d expect the power is still there ? I think it used to have about 4 outlet boxes built in for the IFI controllers.

I’ll push the issue to the GDC so they can comment. Then students going to the next event can carry that doc with them and then they can meet with the event organizers on site. I’m concerned that the venue will resist this unless there is GDC guidance.

I’d imagine if the head inspector want more power well then “Captain we got to have more power !!” ( in my best Scottish accent ). I can see why you would not have a problem getting power.

We have run video equipment that uses more power than the classmate and we have run all day long, EASY !

We also use this setup to run public demonstrations outdoors and corporate / legistaive events indoors. All day long EASY !

Put the battery on the charger overnight. Check the battery midday while inverting just to make yourself comfortable.