Agreed! There is absolutely nothing wrong with the NiCad packs or the old transmitters for that matter.
NiCads can usually output more amounts of power at one point in time than NiHM (the quality of manufacturing, and the mah rating can affect this). Not knowing the C rating on these bats makes them hard to compare, but I recall in some old thread that someone was able to draw 50 amps or so from the 7.2 volt battery. Thatās a C rating of 25 C (You multiply the C rating number by the capacity to see how many amps it can output at once). I donāt know about the new batteries though.
when i looked at them at first, i thought they just rearranges the cells 
so does that mean after every match, you can stick it in the charger again and it will still have its full capacity?
with the old ones we had to discharge fully and then charge them up again
Thank you! I like getting to know people on here as well, maybe I can run by your pit at the world championships, itās always nice to get to know people in real life too, haha.
FUNNY you mention that. At the 2008 World Championship I saw Chinese teams who were using the transmitter to drain the batteries. Then a year later when we went to the Omaha Championship of the Americas they decided to give each team a mini-quiz as part of the judging. One question asked about recharging the batteries. I immediately answered that, yes, Vex batteries need to be fully discharged. Another team member agreed and the other three had no clue. According to those judges, Vex batteries should not be fully distarged.
So tell me, are the Chinese wrong or did the judges at the Competition of the Americaās screw up?
Iām pretty sure those judges screwed up. If you werenāt supposed to completely discharge NiCads, then why do they sell battery dischargers? However, I canāt imagine you draining the batteries well with the transmitter. Get a dedicated battery discharger or build your own with some high-watt rated resistors and a heatsink.
Here is a fairly good article on the subject, but this effect is pretty well explained all over the 'net.
It is a good idea to discharge NiCds before recharging them, but understand that discharge is NOT the same as draining them down to 0V. A NiCd cell is considered discharged when it dips below 1V. Since the Vex batteries contain 6 cells, that means about 6V is as low as you want to discharge them.
I use a 12V halogen bulb wired to a Tamiya connector for this, and Iāve learned to gauge when they are ready by the brightness of the bulb. It isnāt exact, but it is good enough.
I also donāt bother discharging them every time. Rechargeable batteries do wear out, so even if you take care to correctly discharge/recharge them, they have a limited life. You can decide how particular you want to be.
BTW - this is why the 75MHz Vex Transmitters beep so angrily when the battery voltage drops below a certain point - it is to avoid damaging the cells in the battery by over-discharging them.
Cheers,
- Dean
Thank you, Dean. I spend a LOT of time trying to convince people that they do NOT EVER want to discharge a NiCd cell to zero. Itās a great way to ruin a battery pack. Here is a link to an article written by the folks at DeWalt (the cordless tool makers). I suspect they know as much about high-load, short-duration use of NiCds as anyone. http://support.dewalt.com/cgi-bin/dewalt.cfg/php/enduser/fattach_get.php?p_sid=h9xv9GZj&p_li=&p_accessibility=0&p_redirect=&p_tbl=9&p_id=685&p_created=1100020449&p_olh=0
Maybe the question was worded in a tricky way, it still royallyā¦ angered me.
Stupid Omaha and your snow, Florida has no evil snow, HAH! We win. 
oh darn
we now we drain them to 3V
our mentor was trying to get rid of its memory effect
(plugged it back in after every match in the bcit competition)
and we do them EVERY TIME when the robot is dying
maybe we should just to them every 2 charges insteadā¦
BTW, is the old fast action charger continuous?
Meaning, does it check the batteries voltage, then cut the charging loop when it reaches a certain value, or does it continue cycling until the battery is removed?
I never understood the stupid blinking red LEDās.
Noting these two things from the specs page, they auto-shut off when the battery is done. Most chargers for these batteries you get at Radio Shack and whatnot will check for a negative change in voltage and then cut the power.
Iām pretty sure flashing or the light off meant they were done, but Iāve also had cases where they werenāt fully charged and had to put them in again. The FAQ on the forum said the flashing light means the battery is damaged, yet most of my batteries do that and work perfectly fine.
Now that I look at the page, I realize they changed the power cordā¦I still have the chargers with huge brick power units in between the charger and the wall and a standard 12v connection similar to laptop power connectors. I wonder if they charge any different or perform better, or if itās just a more compact and aesthetic look.
Excuse me. Let me rephrase my last post. We spent 7K on four robots, and almost half of that went to a field and travel fees. Sorry for the misunderstanding that weāre filthy rich. Weāre not. We are barely getting by because of travel fees. And no, our school does not give us any money as does yours. We have to do all of funding ourselves via grants, fundraisers, etc.
Thanks for the clarification on the $7K. We limit our normal season to events that are < 90 minutes from our shop. So we have less of a travel costs. And since we hold one of the events we donāt āpayā to go for that.
Topic switch to the battery. Iāve been following this battery website with NASA information and have done a full set of recoditioning on two sets of battery packs that were iffy on holding a charge and it helped them. The site recommends discharge to zero.
I have an RC car unit that Iāve been using and it seems to have worked well.
Hereās a clarification regarding the legality of these new parts at the World Championship.
https://vexforum.com/t/answered-new-products-2010-world-championship/17186/1
Quick sidetrack, since this topic is concerning the new stuff. Being new, I did a search of a topic concerning the new 2 wire motors, and wether they are compatable with the old brain, but didnāt find anything specificly about it. Having a tight money constrant, would it be possable to buy the new motors and use then with the old brain?
Yes. You can use the new 2 wire motors, with a motor controller 29, with the old brain.
Thanks for the info.
u need a āconverter cableā that cost $10 each
for each of the HS motors you plan to use in the old brain