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Old 11-16-2007, 06:48 AM   #136
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So how have people been maintaing these EP cells? Are they touchy like the IB's? I remember EA saying IB's dont like to tray below .7 or so. Can you go farther down with EP's? like .5 or so?

Charging amps.. 6? 7? 8? Kaboom if more?

Storage? have to put 1000mah into them for storage like IB's? IB's like to self discharge some....

about about discharging a pack after it's last use for the day down to 6.0 volts or 1.0volt per cell, then next week, tray to .7 from there?
After a day of racing I like to discharge down to .9v/cell and do a cycle after that to be sure that they are all good and keep an eye on the specs. After cycling, I put a little back in - 1000 to 2000 mah on the charger then store until the night before the next racing day where I charge them all up and peak before the race.

I never charge over 5 amps - even though I sell matched cells I'm not interested in selling myself more than I necessary to myself. I just can't see any sense in charging at too high of a rate. If it makes a difference I'm not seeing it with my moderate driving skills. I want my batteries to last a while.
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Old 11-16-2007, 08:04 AM   #137
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Hey QuickRC
its nice to see someone finally post documented facts about something instead of heresay..interesting facts and points.
thanks
MO
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Old 11-16-2007, 09:34 AM   #138
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Hey QuickRC
its nice to see someone finally post documented facts about something instead of heresay..interesting facts and points.
thanks
MO
Thanks 1fastguy1... Maybe it will catch on.
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Old 11-16-2007, 12:36 PM   #139
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So how have people been maintaing these EP cells?
I charge at 4.5amps, then repeak before the race at 5amps. From everything I've heard there is no benefit from charging above 5amps with these cells. In fact monitoring battery temp and peak voltage I found charging at 4.5-5amps gave better results then the times I tried at 6+amps.

After the race I put the packs on my MM discharge and 30amp pulse down to .9v per cell. If I'm going to use them again the same day I let them sit there, if they will be stored then I out 600mah back into the pack. When I go to charge a stored pack I put in the MM discharger first and linear discharge down to .9v per cell, then right to the charger at 4.5amps.

I've found that the EP are very reliable, performance WAY exceeds the numbers on the labels, and they do not self discharge themselves between uses.
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Old 11-16-2007, 09:04 PM   #140
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So I just got a pack of these and craked the pack open, hit it with my volt meter and low and behold 2 out of the 6 batteries are stone dead. I'll try a 2 minute single cell charge to see if they come up, but me thinks I just got another 4 cell pak. Johnny isn't happy.

So heres the update: 2 minute 5 amp charge per the 2 dead cells, after 12 hours the leakdown voltage on both the bad cells is different. 1 cell although down a little looks like its saveable, the other cell, lets just say it now sits at .053 volts after sitting and had a off charge at 1.48 volts.

Some rather interesting reading of the instructions that come with the cells, from Trinity, they basically say sorry, tough luck for you, we accept no responsibility for nothing, faulty product, or injury when you use this product. So much for a replacement.

Last edited by Johnny Wishbone; 11-17-2007 at 10:02 AM.
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Old 11-16-2007, 09:17 PM   #141
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I charge my EP's at 7 amps! Takes less time to charge. temp cutoff around 130 degrees
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Old 11-19-2007, 05:43 AM   #142
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IB4600's are coming...

http://www.ark-inc.jp/maker/maker.html

http://www.e-seiki.co.jp/
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EP4600's-4600.jpg   EP4600's-4600-2.jpg  
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Old 11-19-2007, 05:59 AM   #143
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Should I buy these or wait for their 5000mah cells to come out?
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Old 11-19-2007, 06:15 AM   #144
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This one must give a bigger explosion

Iíll wait for Norwegian approval....
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Old 11-19-2007, 10:28 AM   #145
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IBs? HAHAHAHA. Good luck selling those
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Old 11-26-2007, 11:23 PM   #146
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So I picked up some unmatched Ep's. Ignorant with batteries, I am using a ProPeak charger, how/should I discharge this pack? I have a bulb discharger I made and a Integy Indy Zero Equalizer. 0.0v cutoff. Should I use either of these? Thanks for any help...
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Old 11-27-2007, 03:23 AM   #147
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Ignorant with batteries.
Statements like this concern me. I know you are being casual with your language but at present we have too many reported cell failures - and the cells are failing most likely due to user error by people that think they are knowledgeable about batteries.

Here is some sound advice that will keep you SAFE and not sorry.

When assembling the packs ensure that no solder whatsoever goes any where near the vents which are around the edge of the positive button.

DO NOT use any kind of 0V discharger with a NiMH pack EVER.

If any cell has dropped to 0V is storage discard it.

Equalise cells on a discharge tray with a cutoff (~0.9V per cell) before charging.

Charge at no more than a 1C rate (in case of a 4600cell, that would be 4.6A)

Use the smallest peak detect you can, or have a thermal cut set at 45C.

Do not store the batteries discharged. Leave a part charge in them.
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Old 11-27-2007, 03:48 PM   #148
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Hey thanks alot, my charger has a set rate of charge at 3.5 amps and shuts off after an hour of charging, i dont think that will peak these cells, I will probably have to give them a break then charge again. Is there any way to make my board discharge less? Thanks for the help...maybe I will give/sell this pack if I am going to ruin them and stick to the stick packs for now.
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Old 11-27-2007, 04:16 PM   #149
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Since batteries have a cycle life around 1000 charges and the deeper the depth-of-discharge(think LEAD-ACID) the more it will shorten that cycle. Would there be any benifit in stock racers who do not come close to dumping a pack to equalize the pack to a higher voltage such as 1.0V, 1.1V or 1.2V? This would shorten the charge/discharge time and not over-work the battery. I would think on a monthly basis, the batteries should be trayed to .90V to give the cell a work out and keep the IR from climbing.

These batteries are not NI-CD's and do not have memory, but NiMH are also prone to irreversible damages caused from abuse. Every time you use a battery, the battery will begin to weaken. Nothing you can do can bring back a battery to its orginal performance, I mean Nothing!. What you can do is prolong the useful life of a good battery. Why give you battery an early death sentence, its your money?
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Old 11-28-2007, 04:44 AM   #150
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Hey thanks alot, my charger has a set rate of charge at 3.5 amps and shuts off after an hour of charging, i dont think that will peak these cells, I will probably have to give them a break then charge again. Is there any way to make my board discharge less? Thanks for the help...maybe I will give/sell this pack if I am going to ruin them and stick to the stick packs for now.
It sounds like your charger would not be suitable for 4200s. I would either invest in a better future-proof charger (one that will do all capacities of NiMH and LiPo safely) or stick to budget low-capacity packs.

Also I do not think modding the board is realistic unless you are an electronics engineer with easy access to cheap single components. Even if you worked out what parts to change, to actually buy them over the counter in small quantities would end up costing as much as a basic 0.9V board!
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