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Old 03-28-2005, 03:12 PM   #841
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Hi All,

I can't believe the 30 seconds extra run time I mentioned in my last post didn't draw any comment? If you are not equalizing now this is pretty huge. This isn't one of those things where I just "think" this is what happens. It has been measured to be accurate.

However I do feel the need to explain a little further. Several tests were completed to see what the difference was when equalising in different ways. Firstly, equalising to 0.9V/cell and cutting off as soon as it reached that point was found to have little to no effect on run time at all. Going down to 0.1v/cell and cutting off was found to have a small effect on cells (between 5 and ten seconds). Only when going down to 0v and holding there for a few hours was the whole 30 seconds run time benefit realised. On later tests we also found that holding at a set voltage gained run time benefits too (I think the test was done holding at 0.3V/cell).

Now a lot of people will say - yes so what, I run stock, won't make any difference to me - I have to disagree quite strongly here. I think we can all agree that during discharge cell volts goes down untill we reach whatever cut off point we use and then the cell is dead. Now if you are 30 seconds further away from the "dead" point this will mean that you are further back on the discharge curve or put another way - higher up on the voltage curve. Having watched cells at the end of discharge this could mean around 0.03V/cell to even 0.1v per cell extra at the end of the run. Let's say you are running 6 cell stock, this would mean you will have between 0.18v and 0.6v more available at the end of your race which translates into higher rpm in the motor.

Please let me know what you think. And if you can confirm or refute that would be great too.

Chris.
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Old 03-28-2005, 09:18 PM   #842
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Old 03-28-2005, 09:33 PM   #843
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I never dead short any battery that needs runtime. Every battery that I have dead shorted has lost runtime and gained some voltage. If I want a battery to have high runtime, I discharge it to .9v per cell on my Novak tray. Here's what I do to each battery for the type of racing it is used in:

stock/ 19t sedan: dead short (0.0v), charge 6amps
stock 1/12 scale: discharge to .3v per cell, charge 5.5amps
mod 1/12 scale: discharge to .9v per cell, charge 4.5amps
mod sedan: discharge to .9v per cell, charge 5amps

-Weylin R.
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Old 03-28-2005, 11:16 PM   #844
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Thanks for the reply mini d. How long do you leave your cells dead shorted for?

Chris
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Old 03-28-2005, 11:34 PM   #845
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Hey guys!

I've been reading the last part of the forum and I read about what Crimson Eagle posted regarding equalizing down to zero volts which is giving him more runtime if not keeping his run time. I've done a few test of my own taking my 1/12 4 cells down to zero volts. I bought 3 of those integy 6S trays and what I've been doing is taking my cells down to 1.0v per cell and leaving them until the next weekend I race.
The morning of my race day I put the cells in the trays and leave them until I get ready to charge. I suppose I leave them in the trays for 3 to 5 hours and I have noticed that i've been putting in 4100 + mah's on charge. It has been great since we run mod asphalt here on a big track. I've just started doing this about 1 month ago and I have seen voltages stay the same and the runtime stay the same too. With time, run times do come down and cells degrade just like anything else.

I'm anxious to see if anyone else is doing the same as Crimson and myself....Take care.
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Old 03-29-2005, 12:02 AM   #846
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I got my first set of Fusion cells today a 4 cell pack. They have fantastic numbers on them even considering they are gp3700's. label numbers are 465 seconds and 1.185v on every cell (yes i did say they are good).

I have to say, this has never happened before and i have cycled a lot of cells. Run time on my charger with a fallback of 0.04v was exactly 465 seconds. It is very VERY rare that any set of cells gets within 10 seconds of the label run time the closest I had got within 7 seconds (and i have seen them as far away as 30 seconds on brand new packs). The voltages was about .005v away which I wasn't surprised about as it was cold in my garage tonight. Charge Mah was 4380 ish and discharge Mah was 3850 ish. I'm finding that these cells take about the same on charge but give up way more on discharge. The pack match for run time was excellent again the best I have ever seen. All cells within 3 seconds of each other to get down to my cut off point of 1.0v.

This is an absolutely phenominal set of cells.... I just need another 3 sets now .

I'm totally astonished, I really was not prepared for this.

Bravo.

Chris.
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Old 03-29-2005, 12:14 AM   #847
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There's a reason why people like these packs . I usually discharge my 19t packs after the race on a 30 amp discharger, then use the dead short mode on my novak tray, then solder a wire across the + and - battery bars until I need to charge them again for racing. Which can range from 1 1/2 hours to a week, but I think as long as they're shorted for 30 min. its good.

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Old 03-29-2005, 07:16 AM   #848
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Chris,
I am going to assume that you saved your data. Please post a jpg of your final data screen from when you cylcled those cells. Btw they will get better voltages in the next 3 cycles or so.



John

Last edited by John Malin; 03-29-2005 at 09:57 AM.
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Old 03-29-2005, 09:36 AM   #849
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John,

I'll do it when I get home this evening.

I'm still having some trouble getting over it, I'm amazed.

Chris
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Old 03-29-2005, 10:31 AM   #850
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Get over it... now go post that data screen - JB
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Old 03-29-2005, 11:03 AM   #851
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I'll have to agree with picco, in that my tests have shown me that in time no matter what the procedure, cells will deteriorate. That said, dead shorting aftr a full discharge seems to give the most repeatable charge over time, but doesn't seem to make the cells stay new......Nothing seems as good as fresh batteries.

It has been a little while since i've trayed my batteries, maybe lazy, maybe feeling like it wasn't worth all the effort, since I race mostly off road....................I'll have to pick up a tray and start again......off to E bay, LOL..............Jim
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Old 03-29-2005, 11:28 AM   #852
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Shame on you Jimbo!!!!!
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Old 03-29-2005, 01:49 PM   #853
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Jim, I have packs from last august that still rip because of the Novak Smart Tray. That thing is like the foutain of youth for cells. For those, I dump to 5.40v on the turbo 35, then tray to .9v on the Novak.

crimson,

That's what you get with Fusion . Only the best.

I also have a few packs that are deadshorts. I usually let them sit two weeks (although sometimes only a week) inbetween uses. However, I do usually use them twice a day, as they are better on the second charge.
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Old 03-29-2005, 10:34 PM   #854
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Hi all,

here is my screen shot of the fusion cells I cycled. Cell 4 reads lower that it actually is I had to tweak my calibration half way through, I imagine it is at least 1.175v.

Killer cells.

Chris
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File Type: jpg fusion graph and data2.jpg (159.2 KB, 104 views)

Last edited by crimson eagle; 03-29-2005 at 10:44 PM.
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Old 03-29-2005, 10:51 PM   #855
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Great Data Crimson!!!!!
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