Which Discharge Tray for GP3300s?

[gizmoguy303]

I figured it's about time to get a discharge tray to equalize my packs. However, I have no idea which one to get. I have matched GP3300s, and need a discharge tray for them. So, which one? Thanks.

[TC3Racer]

I have a Trinity Real Time 2 discharge tray and it works very well. It has built in discharge bulbs and a fan. Works very well and have use it all the time.

[gizmoguy303]

Does it discharge pack down to .9v/cell or 0v/cell? Does it have a bi-polar design?

[racerrandy]

I have the RT2 and it will take them to zero if you leave them on there. When I get the extra bucks I am going to get the new novak tray. You can set the voltage you want it to go to and it takes them down to that and shuts off. Its about 70 bucks I think but you will never kill a pack because you got to talking at the track and forgot about the batts. LOL.

[highroller]

Most of the equalizing trays work the same, only problem one (Pro Match Smart tray) was a little different to use in how cells were aligned. I used the Real Time 2 newer version is the 2.1 and the Integy Octance 2. All will take cell voltage down to zero if left on longer, for a .90 - .25 loosen the contacts either as bulbs dims .90-.60 or when it goes out .10 to .25 voltage range. For GPs and Nicads leave them on for 30-40 min if you plan to use the pack again or is cooled enough to recharge. For other NiMH remove the pack or loosen the contact as bulb goes out for each cell. If you aren't going to use the pack again discharge it to .90 volts per cell and store.

[gizmoguy303]

So if I want to use them again that same day, I should discharge the pack down to 5.4v and then put it on the tray until it is cooled enough to recharge? I don't quite understand what you are saying. :(

[gizmoguy303]

Okay, I am still not clear on how you know when the cell is at .9v. Do I just loosen the contacts right when the bulbs dim? If so, I suppose I have to stare at the discharge board waiting for the bulbs, right? I need to get one of these but still am not sure on how you guys are using them if they don't shut off by themselves.

[Grizzbob]

Okay, I am still not clear on how you know when the cell is at .9v. Do I just loosen the contacts right when the bulbs dim? If so, I suppose I have to stare at the discharge board waiting for the bulbs, right? I need to get one of these but still am not sure on how you guys are using them if they don't shut off by themselves.
Something like that, which is why some of the more expensive trays are hitting the market, like Novak's new one & Rayspeed's tray. Both of those can discharge to a specific level for each cell(I believe the Rayspeed can be set to stop at 1V, .5V or to 0, & the Novak can be set to just about anything you want, in .1V increments). Takes the judgement calls out of it, so you don't have to constantly keep an eye on it to prevent any problems, just set it & forget it.... :cool:

[gizmoguy303]

Thanks for the help Grizzbob. Could you give me a basic "instruction manual" for traying my batteries? For example, should I discharge each cell to .9v after running a race, and then wait for the pack to cool before recharging, or should I leave the pack on the tray until it's cooled enough to recharge? Stuff like that. It would REALLY help. Thanks. :D

[RustlerBoy]

I use the RealTime tray. The only thing you MUST do is when the lights go out, take them off immediatly. If you have the money, spring for the Novak Smart Tray. THat is the best I have seen, and you can adjust the voltage cut off for any setting.

[rcguy2477]

Also check out the rayspeed discharge tray. The cheapest i have seen a good discharge tray is an integy, for $20. My friends have the novak and it is good because it automatically stops once it reaches its setting.

[Grizzbob]

Yeah, with one like the Trinity RT2(which I have), you'll have to just "eyeball it". I just try to keep a close watch on the lights, & when one gets close to going out(dim but not out) then I disconnect that one, & go through all the cells in the pack likewise till it's done. But it's certainly a LOT easier to do it with trays like the Novak or Rayspeed, since you don't have to watch them after starting them up... :cool:

[gizmoguy303]

Thanks for the help guys. I am going to buy a used, but fairly new Real Time 2. What I need to know now is when to use it. :confused:

[Grizzbob]

Well, I use it only on the days I'm going to use my packs, when I first get to the track, I'll get my 20 amp discharger(with a cutoff switch on it) & my RT2 out, & start discharging all my packs for the day. And the first one I'll do is the first practie pack I'll use, after the 20 amp one finishes, I'll tray it & when the lights dim(as I mentioned before) I'll pull it off, let it sit a few minutes, & then charge it. And as that's going, I'll do all my other packs the same way(& just let them sit after I pull them off the RT2 until I need them). Then, as I use them, if I'm not going to use a pack anymore that day, I'll just put it away(I still follow one of the older suggestions we were given about NiMh's, & leave some charge in them for storage), & if it's a pack I intend to use again that day, I'll also leave it be(no discharging) after a run & just repeak it, then do the same with it as the others at the end of the day. Seems to work fine for me, can never tell when my packs start falling off until I've had them for QUITE some time..... :cool:

[gizmoguy303]

Thanks for the play-by-play Grizzbob. Just what I needed. :)

When you are finished traying the first pack for the day, wouldn't charging it immediately after it has just been discharged be bad for the pack?

How much mah are you getting into your packs when you charge them? Some of my older packs will only take 2600mah or so, yet they are only 4 months old at best. I've been following the standard procedure now (store discharged, discharge after each run, etc.), but maybe I need to jump on the Grizzbob Regimen. :p Maybe the lack of using a tray is why my packs are dying so quickly. :confused: It may also be that my older packs were charged on a Duratrax Intellipeak Deluxe for a while, until I bought a Pulsar Competition, which is what I use now.

I just bought an RT2 off someone in the For Sale/Trade Forums and it should be here next week. Thanks for all the help. :)

[Grizzbob]

Well, the packs I charge up immediately after traying are just my practice packs, one's that have slowed a bit, or ones I'm not as concerned about, & to be honest, at that part of the day(before completely cycling them) it doesn't seem to be any real problem. but it probably does help that I try to NOT let the cells discharge completely, so it'll tend to recover quickly & won't be hot at all(in most cases, they don't even warm up since they only have a little charge in them when I discharge & tray them). When brand new, many of my packs have read as high as 3600mah(that my Millenium Pro put into them), but after 6 months or so they do read lower than that on the charger. However, I have yet to notice any significant drop in run time on the track, & that's what matters most(keep in mind that the mah numbers that our chargers generate are just an estimate, based on how many amps it's charging at & for how long, in truth you can't really tell exactly how much has gone into them, that's EXTREMELY difficult to directly measure, if it can be done at all). So I only move a pack into the practice collection when it either loses a more noticable amount of run time, or it just seems to lose its punch, or if I happen to get my hands on a better pack(which has been the case most of this year).... :D

[highroller]

Sorry had some pressing issues and been unable check the boards as frequently.

When it came to NiMh information on care and techniques to care for them kept changing so as the cells change and improve the ways they are cared for and used keeps changing.
We were first told NiMh could not be taken to very low voltage levels, most said between .25 and no lower than .10 volts (thats after discharging down to around a .90 volts per cell level). That's why we were removing them for the equalizing trays when the bulbs went out. Over time and with the introduction of the GP3300 cell, the 2nd and newer generation responded to treatment similar to a Nicad - it could be discharge to a zero voltage level without damaging the cell structure - oval racers (stock and 19turn classes) began dead shorting the packs once they were discharge in the tray. This improved the voltage output but decreased the runtime substantially. The best way most found to care for GP3300 was to discharge the pack to .90 volts (5.40 for 6cell, 3.60 for 4cell it is fine if voltage drops .50 volt) and then storing. If pack was going to be used again that day for racing it was put in equalizing tray - again some information varied depending on how long the pack was left on. If you left pack on until it was ready to be charged - it increased voltage, but shortened the amount of runtime - if you remove it once lights went out you gained less voltage, without the drastic lost in runtime. So it still ended up being two methods to use based on the performance you were looking for. So depending on what type and level of rc use the pack is used for you may use a technique that's completely different as long as you get good results it can't be wrong.

Trinity has also introduced a newer tray retail around 75 - 85 dollars and discontinued the Real Time 2.1 they had just improved the 2.0 and discontinued it.

For offroad/TC stock racing I use 12 bulbs, oval racing 16 bulbs 19turn and modified and leave in the tray for 20-30 min if I plan to use the pack again - modified oval packs are only used once a day - runtime may decrease too much on the second or third cycle. Non racing packs are discharged with a 20amp load, and one bulb is used to bring voltage down further or removed when bulb dims or just as it goes out. Don't have any decent Panasonics cells left, do have some Sanyo 3000, 3000HV, 3300HV any began treated the HV Sanyo the same way as GPs -storing them with around .90 volts per cell up to 3-4 months it did take 2 cycles for some to come back up to normal levels. Some GPs cells have peaked at 4000MAH while a majority of them peaked at 3800, those that I've put through a cycle on my Integy 16x5 and 16x5v6 are comong up with 3400 t0 some 3600mah on 20amp. Some were purchased in Sept 02 and still cycle and run almost the same as when they were new - runtime did fall off too much to be run in mod oval but have plenty of punch for 19turn and stock racing.

[gizmoguy303]

Thanks for all the information guys. I really appreciate it. The RT2 should be here any day now and I'm eager to try it out. :)

[redsixer]

So what is your procedure for race day battery charging? Do you come to the track with your batteries having been tray discharged and then charge them right before you race? Or do you tray them at the track and then charge? Or do you get to the track with your batteries charged and ready to race? It seems to me that the batteries have more punch right when they are taken off the charger. Im just wondering how the more experienced racers prepare for the race.

[Cain]

I use the integy octane 2 discharger. Does 20 Amp discharges down to 0V. Has lights as well.

Love this unit, works great. I dead short my GPs, so its idea for me, you can also just dicharge them down to zero and then pull them off. I haven't lost any runtime, I still charge up close to 4000mah on my GPs. The new GPs are just amazing.

[gizmoguy303]

Okay, my RT2 came in today. It looks brand new. It says Real Time 2.5 on the top of it - I suppose this is the updated Real Time 2?

A few questions:

What amp rate does this discharge at?
Should I connect the fan leads to my 12v power supply, or to the pack I'm discharging?

I'm sure I'll have more later on. Thanks for all the help.

[gizmoguy303]

Another question - on my RT2, the fan sucks air from the case and blows it out the bottom. It seems to me that it'd work better if it sucked air from the bottom and blew it up into the case. What direction does your RT2's fan go? Maybe mine is upside down?

[Grizzbob]

To be honest, that fan is really not a great idea(I really don't use it on mine), that's one thing that the matchers have told us all repeatedly, that we should NOT artificially cool the cells, let them cool down on their own, so I don't mess with the fan at all. As for it saying RT2.5, I'm not really sure, Trinity does have a new tray, but not sure if that's it(I think their new one has a slightly different name), but the 2.5 might indicate the discharge rate, so if I'm right, it'll discharge at 2.5 amps per cell.

[gizmoguy303]

It seems that the fan would just keep the resistors cool. I don't want to fry the tray by not using the fan, or having one improperly oriented. Those resistors get pretty hot after equalizing one pack that has been already discharged to 5.4v.

Trinity's new tray is the "Absolute Zero" tray or something like that. I believe they discontinued the RT2, but I don't see why.

I'm just curious - are these trays designed (i.e., up to the task) of discharging a fully charged battery? Thanks for the help...again. :D

[jdwcanj]

Mostly good information here, guys. A few additional guidelines:

Firstly, before charging after traying you should allow the cells to cool off before putting the charge in them. After being in the tray the cells are typically pretty warm. We're finding that the packs have better voltage output when charging is started *once they've cooled down*. There is some rebound in voltage before the process of charging, but that's to be expected.

Secondly, peaking more than once before your heat/main is a no-no. Make sure you peak *once* right before your heat and that the peak was started once the cells were cooled off.

Thirdly, dead-shorting will indeed bring the voltage of the pack up *some*, but the damage done to the cells usually outweighs any performance gains you may get (usually 0.01-0.03V) per cell. From our findings the lifespan of deadshorted cells is definitely shortened by this process.

-jon
Surge Battery Matching
www.surgebatterymatching.com
'Resistance is Futile'

[Cain]

I haven't had any issue with dead shorting. I use SMC instructions on dead shorting. Works great. For a newbie or someone less inclined, feel free just to do the non-deadshorting instructions.

[jdwcanj]

I haven't had any issue with dead shorting. I use SMC instructions on dead shorting. Works great. For a newbie or someone less inclined, feel free just to do the non-deadshorting instructions.

Deadshorting is fine as long as you're willing to deal with the long-term repercussions. You *will* see the runtime of your packs deteriorate. For instance on a 430mah cell you will on average see a 15-30mah decrease.

-jon
Surge Battery Matching
www.surgebatterymatching.com
'Resistance is Futile'

[highroller]

If I don't plan to use the pack again it is discharged and stored. On race day I take them to the track place in equalizing tray until lights are out or for 5-10 minutes then charge them. Only packs that I dead short are those used for 19turn 4cell oval (these are packs that declined too much for mod oval) - packs may develop to much voltage for stock offroad or loose too much runtime to be used in mod racing. I generally know at what point or how long the pack takes to charge 38 -42 minutes at 7amp for oval, 48-52 minutes at 6amps if pack peaks and 10-15 minutes or more have gone by I repeak just has the heat before mine begins or wait until they are about 1.5 to 2minutes into their race.


I generally try to purchase packs for their specific type of racing and treat them accordingly. Found out over the years when using packs for oval mod racing where they were subjected to high discharge loads developed to much voltage when used in offroad stock - and those used in offroad stock (lower charge/discharge loads) were too soft or didn't have the punch when used in stock or modified oval. The batteries numbers aren't a big issue in stock tc and offroad as they are in oval or modified racing. For me 390 runtime, 1.15-1.16 voltage is plenty but in oval nothing less than 400 runtime, 1.17 voltage for race packs.