Battery Life
 

Hi,
We are having a big issue with the life of battery on the robot. Even we charge the battery until it gets fulled, it only lets us 20 minutes of practice. Moreover, depending on the change of voltage on battery, the robot doesnt do what we say in the code especially in autonomous. What else can be done to solve this problem ?
And one more question: Are we going to be given charged batteries before every match at the competition ?

Thanks guys!

Re: Battery Life
 

Well, during the competition, you WILL have to provide your own batteries and charge then quickly before each match and cycle the charges will other batteries when they are done. It is going to be crazy!

What code did you set to your robot, this could be variable and could mean working or not!

How many batteries do you own and how old are they
What kind of charger do you have and it's charge settings.

What is the voltage reading on the driver station ranging from?

I hope this info helps and that we can solve this issue!

Good luck and Happy Competitions!::ouch::

Re: Battery Life
 

If your autonomous code is being affected by the battery voltage, I assume your code is doing dead reckoning (timed drive). If you want to have more accurate autonomous code and be independent of battery voltage, you should make use of sensors (e.g. encoders, gyro etc) for close-loop control.

Re: Battery Life
 

20 minutes of battery life is actually really good.

If we can get two matches out of one charge we are happy. I can see some machines this year with all the motors allowed not getting more than one match per charge.

We take at least eight batteries to every competition.

Re: Battery Life
 

We have several old batteries, as well as 4 fresh for this year, we are considering getting more. Having fresh batteries is one of the most important things to keep track of, we named ours to keep track of which ones perform the best and are charged.

Re: Battery Life
 

If things haven't changed from the past few years, the Seattle Regional spare parts box should have two "international" batteries reserved for you to borrow for the weekend. You will be responsible for charging them.

Re: Battery Life
 

To make sure you always have the battery you want, organize them in some way. We have a system that seems to work well for keeping batteries straight.

1. Number your battery with its first year of use and a designation number (to distinguish between multiple from the same year).
2. Color code the batteries with some sort of easy read system (i.e. electrical tape) for how they should be used (for us, silver is competition ONLY, orange is practice/maybe competition, black is poor charge/too old, and red is Do Not Use, i.e. cracked).
3. Sort your storage location, ideally for every designation, plus one for all designations waiting to be charged.
4. Label your batteries with their post-charge voltage for reference (remember to wait a few minutes after they come off the charger to settle to their actual voltage). Sticky notes do this well.

Re: Battery Life
 

So, in summary
1. 20 minutes is good, some robots get only about 10 minutes
2. See mikets post
3. You must charge your batteries for every match. Bring enough chargers!