Be aware of battery and charger inconsistencies!

[sanelss]

Anyone who has sufficient FRC experience knows that batteries are paramount to a robot's functionality. It can cause major problems if not properly taken care of. A loss of speed, general degradation of performance, and worst case is missing a goal and losing out on those points! We rather interestingly ran into this situation this year and actually found a good fix. We have noticed these symptoms in previous years but never really thought too much of it.

Short background story:
The issue arose when every time we did a battery swap the robot's performance seems to be altered. sometimes the balls would shoot higher, sometimes lower, the robot had a noticeable speed difference, and we couldn't figure out what in the world was going on. We had all good chargers and good batteries from last year. After some investigation we had concluded that our issue was the batteries! not just the batteries but the chargers as well!. The most typical problem is the connector coming lose but that wasn't the case for us. What I had noticed is that anytime a battery came off a specific charger it seemed to have much better performance. We had two of these chargers but the other one didn't perform as well. We also had two other newer style but those also didn't perform as well. Now you might be thinking they are defective, but i assure you they arn't they are all 100% fully functional.

Technical details:
-Battery age matters, avoid using batteries more than a year old
-connections matter
-chargers matter! just because you have two identical ones doesn't mean they will behave the same. we had 5 chargers and each one had charged the battery to a different voltage ranging from 12.8-13.3
-battery charge, you need to have enough batteries and chargers to keep your robot alive during competition! These batteries take a short while to discharge and long time to recharge so don't think 5 minutes on a charger and it will be good to go. Not only do you want a charged battery, but you want a FULLY charged battery to an optimal level.

Solution:
-Upon the recommendation of another team(sorry forgot which) we currently use: http://www.amazon.com/Stanley-BC1509...tanley+charger

(there are other types as well with higher current or other brands this is just one particular example i can vouch for)

for all our battery needs and are very happy with them so far. The key aspect is consistency. We have 3 of these chargers now and they will charge the batteries to the same point every time on every charger so we have resolved all of our battery inconsistency issues.

TLDR: get good chargers,test what your current ones do