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"Over Peak(delta) Voltage Cutoff"

"Over Peak(delta) Voltage Cutoff"

Old 09-20-2004, 10:37 PM
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Post "Over Peak(delta) Voltage Cutoff"

I have purchased a Reedy Quasar charger. It has an adjustable feature that allows you to adjust the "Over Peak(delta) Voltage Cutoff". I can adjust from 3mV to 10mV. The instructions say 5mV is recommended.
Can someone please tell me what this does? Is lower or higher better? How will this affect my Charging and Discharging? Battery Life/Performance?
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Old 09-21-2004, 01:35 AM
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During charging, the pack voltage raises slowly. At the end, the voltage increases faster and then drop suddenly. This is called a peak and at this point, the charger should stop.

Packs are different, so the peak cut off should be adjusted to suit your packs.

Start with the recommendations. If the pack dont false peak (shut off too early) and it's not too warm at the end, then you're there.

If false peaks occurs, increase the peak cut off. If the pack gets too hot / warm, decrease it.

The warmer the pack, the more punch, but at the expense of battery life. It's about finding the happy medium.

If your packs are quite new, the recommendations will be just fine.
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Old 09-21-2004, 03:44 PM
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Cole: since you seem knowledgable about battery packs I have a question for you:

When I charge my 2300mah AA batteries, which are rated at 1.2 volts (I charge them as a pack of 4, so 4.8 volts) is it bad that the charger shows 6.- - volts while charging???

I'm using a Indi 16x7v6
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Old 09-21-2004, 07:19 PM
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No,If you charge a 6 cell(1.2 x 6 = 7.2)the charger will read from 8 to 9 volts.The same in your "real" car, 12 volt battery and it gets charged at 13.5 to 14 volts.If you tried to charge at 7.2 volts it would not really have 7.2 volts when you took the charger off of them.At that low of voltage it would only be a float charge.
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Old 09-22-2004, 01:10 AM
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CorvetteCrazy: That's absolutely normal. The 1,2 is the "nominel" voltage, it's not that accurate. At best, it's close to the average voltage during discharge.

The voltage may vary, depending on battery age, charge rate, discharge rate and temperature. And during a charge, the voltage will increase over time. During discharge, the voltage will decrease over time.
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Old 09-22-2004, 01:47 AM
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Default Re: "Over Peak(delta) Voltage Cutoff"

Originally posted by Billy
I have purchased a Reedy Quasar charger. It has an adjustable feature that allows you to adjust the "Over Peak(delta) Voltage Cutoff". I can adjust from 3mV to 10mV. The instructions say 5mV is recommended.
Can someone please tell me what this does? Is lower or higher better? How will this affect my Charging and Discharging? Battery Life/Performance?
With my Quasar charger I use the recomended 5 mv cutoff during charging and a 6 mv cutoff when I repeak. I equalize and charge my packs the day before a race if I can and pepeak just before im going to use them.

The higher number cutoff the more charge will be packed into your packs, but it will also increase heat. You want to have your packs between 120'f and 140'f after the charge. I have some old 3000 packs that need a 7mv cutoff to get hot enough to be fully charged. Getting your packs this hot before you run excites the batteries internals and will give you more punch at the beginning of a race. I use an infared temp gun to check the temp after a charge.

The larger amperage setting also has alot of effect on how your packs work and last. Lower amp charging promoted longer runtimes and is better for the life of your cells. Higher amp charging promotes higher average voltage but at a cost of runtime and battery life.
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Old 09-22-2004, 02:49 AM
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SpeediePhatt, I'm wondering why you're charging the day before? Aint your pack slow/lazy this way?

I've tried charging 3-4 hours before race. I've tried with NiCd1700, 2400 and Sanyo 3000 HV. At the track I used my Eagle CDC 6 Boosting feature, and I havent been impressed! The packs comes off with nice temperature (checked with temp gun), but they definately was flat, too little punch. Actually the 1700 responded the best to this, but this pack also seems to be less sensitive to charging technique than all others I've tried.

Buttom line: These packs perform much better, when just fully charged right before use.

I havent tried with my GP3300's, since I'm not convinced by performance, and not sure if it'll hurt performance in the long run.
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Old 09-22-2004, 08:37 AM
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he repeaks them right before he uses them
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Old 09-22-2004, 01:44 PM
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Originally posted by ctardi
he repeaks them right before he uses them
Okay, I did get that point, but forgot to mention, I've also tried that; With the same dissapointing result: Flat cells, with very little punch.
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Old 09-22-2004, 02:24 PM
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dunno, works good for me
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Old 09-23-2004, 02:10 AM
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Is it possible that GP3300 responds better to a re-peak and/or boost?

Elsewhere I often hear that nothing beats a full straight charge, just before the race.

It's quite interesting, because I'm close to get an extra charger, to avoid all that waiting for charging a GP3300 for 45 minutes....

Thanks.
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