After three seasons, our pair of robots become very unreliable.  Back to back runs of the same program started to yield vastly different results.  We were using the rechargeable battery pack and even when they were fully charged, the robots continued to act odd.  Our junior coach suggested replacing the packs with new AAs, just to check.  Since it involved disassembling the robots, we were reluctant.  He insisted and lo and behold, the robots were once again running consistently.  That evening, we ordered a new pair of rechargeable battery packs.  Since then, the robots have been running consistently.

My advice?  Use the rechargeable battery packs and replace them every two or three years.

John
Lake Anne Sea Monsters

On 10/20/2010 10:03 AM, Sonya Shaver wrote:
[log in to unmask]" type="cite">Yes, this is my ultimate dilemma also.  We have used the rechargeable battery pack for two years.  This year we began using the same one for the third year, but we went ahead and replaced it and are now using a new one.  I think the advantage is not having to disassemble the robot and change the batteries, not wasting all those batteries, or not having to worry about taking out the batteries and recharging them.  With the rechargeable battery pack, you just plug it in.  And you can check what the charge is on it if you feel like it is faltering.  I feel like this is working okay for us, but I am wondering if I am missing something!

Sonya


On Wed, Oct 20, 2010 at 9:48 AM, Jude Arulpragasam <jwanim[log in to unmask]> wrote:
I would like to know if there is any advantage using re-chargeable battery pack over individual AA batteries'?
I just bought new re-chargeable DC battery pack (NXT Rechargeable DC Battery (W979693) from Lego website.
 
Please give me some pros and cons  on this
 
Thanks
 
Jude
 
Date: Tue, 19 Oct 2010 20:36:44 -0700
From: [log in to unmask]

Subject: Re: [VADCFLL-L] NXT batery warning
To: [log in to unmask]

Our team started using AA batteries instead of the rechargeable battery pack. But when they had to change the batteries, they had dismantle the robot to get to the battery compartment. I am worried that the kids will not put back the robot perfectly, if they have to do this just before the tournament to have fresh batteries in. Is that how it is normally done?

thanks
Gaja

From: Jerry Lorengo <[log in to unmask]>
To: [log in to unmask]
Sent: Fri, October 8, 2010 3:28:54 PM
Subject: Re: [VADCFLL-L] NXT batery warning

Agreed - always use fresh AAs. 

The recharchable batter has a goofy memory and the voltage drop will make reproducibility for missions almost impossible. 

Sent from my iPhone

On Oct 8, 2010, at 12:48 PM, Lloyd O'Hara <[log in to unmask]> wrote:

We only use batteries and always make sure we have plenty on hand.
 
Also, I'm sure why you would take 2 sets of four AA batteries, the nxt takes six AA..
 
Lloyd
----- Original Message -----
From: [log in to unmask]" rel="nofollow">Viquar Shaikh
Sent: Friday, October 08, 2010 10:50 AM
Subject: Re: [VADCFLL-L] NXT batery warning

To add to this --- no matter what - we always carry 2 sets of four AA batteries - one is a new packed set. This is a good backup for these 'just-in-case' scenarios.
 
Thanks
Viquar

On Fri, Oct 8, 2010 at 10:32 AM, Brandy bergenstock <[log in to unmask]> wrote:
This came across the Ga FLL yahoo group adn I thought it was important for everyone to realize:

The other day my team had taken one of their NXT bricks with them to a meeting.  When we got home, the battery was completely discharged. After recharging it, my  daughter discovered that the "Sleep" setting was at 60 minutes. The brick had  accidentally turned on during transport and since the sleep setting was so long,  it ran the battery down. We discovered that the 60 minute setting is the default for both the 1.26 and 1.31 firmware update. That is WAY too long!

If you have updated your firmware, you should check the sleep setting and change  it is a more reasonable time (perhaps in the 2-5 minute time frame). This way you won't accidentally run down your battery. I'd hate for someone to discover their battery was dead when they arrived at a competition.

To access the sleep setting on the NXT brick, go to:

Settings
Sleep
and then change the time with the arrow buttons

To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.
To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.
To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.

To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.
To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.

To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. 

-- 

John J. Barrett
Industrial Medium Software, Inc.
1616 Anderson Road
McLean, VA 22102

(c) 703-231-5094
(p) 703-286-0818
(f) 703-286-0888

http://www.industrialmedium.com
To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.