help with discharge trays
07-01-2005, 12:54 AM
#46
Originally Posted by MTX
Just a few question..
How do you guys normally discharge the batteries after the race... can I put straight the battery to the discharger such as novak smart tray. or I need to discharge the batteries at certain amp first before it go to the tray? can some one recommend the best way to take care the batteries after use...
How do you guys normally discharge the batteries after the race... can I put straight the battery to the discharger such as novak smart tray. or I need to discharge the batteries at certain amp first before it go to the tray? can some one recommend the best way to take care the batteries after use...
I charge with Novak Millenium Pro chargers at 5.5 on NIMH. I then peak once at 7 amps on the Pro Trak just before putting the car on the grid. After the race I leave the packs a few hours to cool down properly then tray to 0.9 on the Novak Smart Tray, and put them away. Before re-using I stick them on the smart tray at 0.9 again.
It's very basic and very conservative but it means my packs finish the season in as good a state as they start them. I pay for my own packs so I can't afford anything dramatic, even if it does give a bit more punch.
However as I said earlier, it's the results that count, so it seems that what we are doing is working well enough.
07-01-2005, 12:56 AM
#47
Originally Posted by JayBee
No problem johnbull, I'm sure there's gonna be some BD questions you can answer for me 
Too bad you can't answer any RDX questions 
-JB
Too bad you can't answer any RDX questions -JB
07-01-2005, 02:09 AM
#48
Tech Adept
07-01-2005, 06:22 AM
#49
Originally Posted by billtc3
Talk about bringing new life into older cells.
This devise will reduce internal resistance and bring runtime back....
You have to be methotical though....
I run my pack in my car....No more than 5 Mins because that is what we do for races...(its a numbers thing)... Once i am finished with marshalling. I pull my pack out and put the the Battery Manager on it.... It does take a while but it discharges at 35amp and gives you all the data that you could want from a pack. It give Average VOltage, Capacity, internal resistance, energy and runtime. I have a spread sheet just for this...My older packs are now becoming decent race packs...Want to save your cells even from the grasp of the dead short mythe...This makes the difference. It doesn't show dramatic results from brand new or only cycled 2-3 times pacsk but for little bit older packs it really makes a difference....If I am lying then you better look through the pits at every major event...where Intermeidate guys are racing...Pro don't need it because they get new cells every race so...But for you and me joe schmoe...It really helps... Once they are finished on the Spintec I store them until the next time I race then onto the Zero 6 trays (yes trays...6 to be honest...3 for stock and 3 for 19T..we do two quals and a main here)...
Sorry I am writing so much it just really helps the middle level racer...
Hope this helps,
-Shookie <><
07-01-2005, 06:37 AM
#50
Tech Adept
whatever...
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
07-01-2005, 06:59 AM
#51
Originally Posted by billtc3
whatever...
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
I was sharing what I do prior to the trays...Did you completely read my post?
Sheesh dude drink less caffine this early....
-Shookie <><
07-01-2005, 06:59 AM
#52
Originally Posted by billtc3
whatever...
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
the batman is not a discharge tray, it's a discharger and it doesn't equalize the cells.
oh, and if you want to f..k up your nimhs, sure, put them on a zerowhatever tray and let them drop down to zero volts
So we,ve discussed zeroing and dead shorting and we all seem to be in agreement that it does nothing for your run time or battery life.
Now to unit discharging. Again, this has it's flaws. No 6 cells are absolutely equal. With every cycle they go out of synch even more, unless they are regularly equalised. So far so good.
So lets take a pack that's been cycled a few times and hasn't been equalised. You've just finished your race and your voltages are, say 1.1,1.2, 1.1, 1.2, 1.2, 0.3. That's a total of 6.1 volts if my maths are correct. Put them on a unit discharger that discharges to 5.4 volts. It doesn't recognise that one of them is already at 0.3 because it only recognises a total voltage, and not individual cell voltages. It will naturally discharge all 6 cells at the same rate. And yes, you've guessed. By the time it gets to 5.4, your last cell has gone below zero, reversed, and is only good for the bin.....or ballast.
The more I read, the more I will stick with my conservative method.
07-01-2005, 07:09 AM
#53
Tech Adept
Originally Posted by Mr. Shookie
You talk like you are the RC Ruler and Master....all of 35 posts too...
I was sharing what I do prior to the trays...Did you completely read my post?
Sheesh dude drink less caffine this early....
-Shookie <><
I was sharing what I do prior to the trays...Did you completely read my post?
Sheesh dude drink less caffine this early....
-Shookie <><
07-01-2005, 07:21 AM
#54
Originally Posted by billtc3
you really have read all my 35 posts? i'm no ruller and master and i hardly talk like one. this thread is for discharge trays, thats what i thought we were talking about. looks like others share my opinion. didn't mean to offend you
Now johnbull, you know I have much respect for you and your opinions and race record...I am just using what works for me in stock and 19T I am not saying the way you do is wrong...in fact that was the same thing I did until what I am using now. Really it is up to those who are paying for there cells what they shoudl do with them. I liek what I do and I have great resolts.
although I might go back and try the other way and see if there is really any difference in runtime and lap times becasue we all know that is waht truely matters....In fact I will try it next time I go and practice.....I will elt you all know what I find.
-Shookie <><
Oh I meant no harm from what I posted. Just disagree on delivery.
07-01-2005, 07:37 AM
#55
Originally Posted by Mr. Shookie
Now johnbull, you know I have much respect for you and your opinions and race record...I am just using what works for me in stock and 19T I am not saying the way you do is wrong...in fact that was the same thing I did until what I am using now. .
But are you with me on the business of unit dischargers - that don't monitor each cell independently?
The nice thing about this hobby and these forums is that we keep learning all the time, and it's good that people can share their experiences, especially if it saves us some money at the end of the day.
07-01-2005, 07:42 AM
#56
Originally Posted by johnbull
Ok. That sentence sorts it all out. With stock and 19 turn duration isn't really an issue. Iam looking at it from the angle of mod, where even with 3700 every second counts.
But are you with me on the business of unit dischargers - that don't monitor each cell independently?
The nice thing about this hobby and these forums is that we keep learning all the time, and it's good that people can share their experiences, especially if it saves us some money at the end of the day.
But are you with me on the business of unit dischargers - that don't monitor each cell independently?
The nice thing about this hobby and these forums is that we keep learning all the time, and it's good that people can share their experiences, especially if it saves us some money at the end of the day.
-SHookie <><
07-01-2005, 08:15 AM
#57
runtime is a big issue around my part of the country. one local on road track runs 6 minutes heats for stock and 19t. a off road track is experimenting with 8 minute heats and 10 minute mains.
for me, what i want and need, is for someone to come out with a equalizing tray that doesn't take the cells to zero but instead monitors each cell down to .09 and will hold them there.
and i am having second thoughts about discharging at 30 amps also doesn't this also reduce runtime? if so. pm me i have a reactor 30 for sale
for me, what i want and need, is for someone to come out with a equalizing tray that doesn't take the cells to zero but instead monitors each cell down to .09 and will hold them there.
and i am having second thoughts about discharging at 30 amps also doesn't this also reduce runtime? if so. pm me i have a reactor 30 for sale
07-01-2005, 10:16 AM
#58
All,
In my experience, there is a big difference between equalising to 0v and dead shorting. When you dead short you risk losing cells, I have seen this happen many times. Equalising, if done right will not do this. Dead shorting costs you run time generally but not in all cases. The voltage you gain from dead shorting is a myth. If you like I can explain this. Most people on here want to keep thier cells for some time, maybe a year or more, I'm one of those people. Reverse charging is one of the best ways to reduce cell life however the example gave earlier of some cells being at 1.2v and another at 0.3v is highly unlikely unless the pack is fried anyway.
After I race I discharge at 30A to 1v per cell then put them away until the day before the race. I will then take them out and equalise them for at least 2 hours each preferably 4 and I like to use my integy zero which is a very mild equaliser - 0.5A. I don't think it's a bad idea to discharge at a higher amperage to 0.9 first but you have to have a positive cut off. On the day of the race I'll put them back on the equaliser and leave them there until I take them off to charge.
As I said earlier, doing this has only lost me 3 seconds run time and gained me 0.05v for the pack. Check out the fusion thread, there is some graphs in there if you want the proof. Generally I get 4300Mah+ in my 3300's and 4700Mah+ in my 3700's.
Chris
In my experience, there is a big difference between equalising to 0v and dead shorting. When you dead short you risk losing cells, I have seen this happen many times. Equalising, if done right will not do this. Dead shorting costs you run time generally but not in all cases. The voltage you gain from dead shorting is a myth. If you like I can explain this. Most people on here want to keep thier cells for some time, maybe a year or more, I'm one of those people. Reverse charging is one of the best ways to reduce cell life however the example gave earlier of some cells being at 1.2v and another at 0.3v is highly unlikely unless the pack is fried anyway.
After I race I discharge at 30A to 1v per cell then put them away until the day before the race. I will then take them out and equalise them for at least 2 hours each preferably 4 and I like to use my integy zero which is a very mild equaliser - 0.5A. I don't think it's a bad idea to discharge at a higher amperage to 0.9 first but you have to have a positive cut off. On the day of the race I'll put them back on the equaliser and leave them there until I take them off to charge.
As I said earlier, doing this has only lost me 3 seconds run time and gained me 0.05v for the pack. Check out the fusion thread, there is some graphs in there if you want the proof. Generally I get 4300Mah+ in my 3300's and 4700Mah+ in my 3700's.
Chris
07-01-2005, 11:08 PM
#59
as far as i know some factory suggest us to discharge the pacs and left it to 0.9 volt (each cells) on the nimh, And some ppl even put those nimh on the tray for a night or even longer than that. which way would be a better one that i should follow in order to get my packs in a good condition..
07-02-2005, 10:15 AM
#60
Hi All,
While I remember, dont' equalise IB cells, they don't like it.
Chris
While I remember, dont' equalise IB cells, they don't like it.
Chris