Teams using strategy to go under the low portion of the bridge (north wall) 
may benefit from using AA batteries because the lithium rechargeable battery 
pack adds about a 1/4" in height to the NXT brick.


----- Original Message ----- 
From: "John Barrett" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, October 14, 2009 9:58 AM
Subject: [VADCFLL-L] A note on rechargeable batteries

> Everyone,
> Just a heads up here.  Over the past two weeks, the pair of robots we use 
> have started to exhibit some strange behavior.  For example, turns were 
> becoming increasingly inconsistent and the robot would sometimes move in 
> jerky movements at slow speeds.  The robots are 3 and 4 years old and 
> initially we thought it might be a motor problem or possibly the new NXT 
> software.  Our teenage mentor suggested that the Lithium Ion batteries may 
> be going bad.  While we were initially skeptical, since both batteries 
> showed full charges, we replaced the rechargeable batteries with alkaline 
> batteries and the robots were back to their "normal" selves.  Aha!
> The lesson here is if you're using a robot with a rechargeable battery 
> that is a few years old and you see some strange behavior, try swapping 
> out the rechargeable with a new set of batteries.  It could save you and 
> your team from going mad.
> John
> -- 
> John J. Barrett
> Industrial Medium, Inc.
> 1616 Anderson Road
> McLean, VA 22102
> (c) 703-231-5094
> (p) 703-286-0818
> (f) 703-286-0888

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