C19: During each competition match, your robot may be powered by only one of the two batteries provided by FIRST.
Does this mean we can only use TWO batteries for an entire day of compeition? That dosen’t sound very reasonable since I know our team (and others) switch batteries after every round. Are we allowed to purchase more Exide batteries to use?
I would imagine yes. I know of past teams who had 5-6 batteries in their pits.
The rule doesn’t really mean you can’t have more than 2 i think, it just means you can’t have more than 1 on your bot at one time…
*jeremy
I think our team is upto having around 10 or 12 batteries in the pit.
I already know 1 is the max on the robot.
But the rule makes it sound like: FIRST sends two batteries and one charger to each team. It is illegal to use any other battery in competition.
btw: our team usually carries at least 6 batteries per event
To sum this up
FIRST says you can only use one of the two batterys. They mean that you can only hook up 1 battery on the robot. You can have as many as you want charging in the pit. When you feel you need a battery change, pop it out and replace it with a fresh one. Most teams change batteries after every match they compete in. You can have several chargers and several batteries waiting for you in the pits
Two batteries would work, have one charging while the other one is used to compete and switch off every round 
I would recommend bringing at least 3-4 so you won’t be in such a hurry to recharge batteries.
I still don’t understand the reasoning behind changing every match, but I suppose thats for another thread.
Anyways, if you do buy more batterys, make sure they are the same kind. Several companys make very simular ones, but they are not legal. The diffrences are pretty small, so check carefully.
-Andy A.
heheh, also make sure (dunno if you can or not) to have a battery or two onhand so if you have to quickly go somewhere or something you have another battery to swap in 
If you don’t change your batteries every match then you may have problems with low battery during the next match and your robot may end up hard to control or may just stop.
*Originally posted by Andy A. *
**I still don’t understand the reasoning behind changing every match, but I suppose thats for another thread.Anyways, if you do buy more batterys, make sure they are the same kind. Several companys make very simular ones, but they are not legal. The diffrences are pretty small, so check carefully.
-Andy A. **
As HolyMasamune said, the low battery could be a problem, especially when a robot pulls 200 amps at a certain time period 
heh we know all about that. Plus if you do not use all of your batteries, you can loan them to partners in the elims match or teams in need of them. Its just good GP
As HolyMasamune said, the low battery could be a problem, especially when a robot pulls 200 amps at a certain time period
:ahh: How do you pull that off without breaking something? Hey just tell me how you pull that off?
It takes a few seconds for the breakers to turn off. That’s one of the reasons we can’t use the old victors this year.
If you pull 200 amps, your risking some serious damage to the battery. Even short spikes raise the batterys internal temp.
If you can start with a fresh battery at the start of the match, and then end up with a low battery in the next, your pulling way, way to much current. Something is wrong.
But like I said, this is really for other threads, and there are a few of them.
-Andy A.
At certain points during our earlier regional matches we pulled 200amps for a period of about 15 to 20 seconds. Then the breakers kicked in. Thats the risks you have to take with a powerful drive system. Once some modifications were made we had fewer problems with current draw.
<edit> No speed controllers, or spikes were ever destroyed </edit>
K…so first you need to understand that a battery is fully charged if it reads 13 volts but a more accurate indication of state of charge is to determine if the charging current is 3 amps or less.Get a mated pair of ANDERSON connectors.Run the battery lead to a 1/4 20 stud.Then terminate the feed to your mainbreaker at this stud and the anderson .Screw the anderson down with #8 screws near the perimeter of the bot .The battery should all ways be located on the perimeter for ease of access.
Now here is the good news …the charger suppled this year finally has some guts and will charge your bot between rounds .Prior chargers did not …take that plastic one you got last year and mark it NOT FOR COMP use it as a doorstop…The best news i this years charger has a thingy in it that looks at charging current at or below 3 amps then the GREEN LED turns on .On the charger …cut the wimpy clips off and terminate the other anderson connector on the charger leads.
Before you go to an event charge a batt and dont take it off till the green led is on .Then place tape from the top to the side of the case over one of the terminals with the date when charged.
When the bot comes into the pits someone has to be charged (sorry couldnt avoid it ) with the responsibility of connecting the charger at the new anderson dicsonnect and conforming the green led on before you are ready to go back out and if not swap the battery out …we have never had to do that. You can read my rant in electrical on the same topic GOOD LUCK Jim:ahh: