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Transmitter pack charging?

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Old 08-25-2004, 05:57 AM
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Vortec
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Default Transmitter pack charging?

Someone at my field recently said that fast charging your plane packs is fine, but fast charging your transmitter pack is REALLY bad.

Can any one tell my why this is? Arnt they the same type of cells (NiCd)? Hense be able to handle the same type of charging.

Should they be removed from the transmitter case if they can be fast charged,or is the charge jack fine for this..

I ask, as ive fast charged my Tx at the field when ive wanted to stay longer and it gave my no problems.
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Old 08-25-2004, 10:32 AM
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dirtybird
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Default RE: Transmitter pack charging?

As you have found it works just as well for the transmitter battery as it does for other batteries.
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Old 08-25-2004, 04:04 PM
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Lynx
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Default RE: Transmitter pack charging?

Slow charging gives you slightly more capacity, and doesn't stress the cells out as much as fast charging does so your packs will last longer on your plain or in your tranmitter if you slow charge them.
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Old 08-25-2004, 08:12 PM
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Default RE: Transmitter pack charging?

I wouldn’t care about the theory. If you have TX pack 600mah or RX pack 600 – 1400 mah I suggest you do not use fast charge for them. Charge TX with 200 mah and RX 200 – 300 mah not more. I killed few JR packs this year trying to charge them fast.
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Old 08-26-2004, 04:53 AM
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Default RE: Transmitter pack charging?

Thanks guys..

I fast charge at 3.0A on my Swallow charger when at the field, but the Tx only gets done when i need it.Other wise a slowcharge..

Just wanted to know if it would hurt the Tx in anyway,or the battery.Dont want a $500 radio going up in smoke.
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Old 08-26-2004, 05:40 AM
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Default RE: Transmitter pack charging?

A 3A charge on a "standard" 600 mAh Tx pack represents a 5C rate!!! This is way too high for any NiCd or NiMH battery. A 3A charge rate might be OK for a 1500 mAh pack - representing a rate of 2C but this would be the maximum I would suggest.

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Old 08-26-2004, 10:51 AM
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Default RE: Transmitter pack charging?

You can fast charge the installed Tx pack if you use sane charge rates (1C is fine) and you keep an eye on things.

The issue with fast charging a Tx, with the pack still inside the case, is that most folks tend to not monitor it. There have been a few examples of where the pack had been over charged (charger malfunction, setup error, bad karma, etc.) and the Tx went into meltdown. Literally.

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Old 08-26-2004, 11:45 AM
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Default RE: Transmitter pack charging?

Fast charging a pack will be the same weither it is in a TX or RX just remember to make sure that you don't exceed 1C and also make sure that your charger does have it set for the right number of cells. Some chargers will look at a partically charged pack as one cell higher and fry the pack.
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Old 08-26-2004, 11:26 PM
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Default RE: Transmitter pack charging?

Keep in mind that the wiring and circuit boards are not designed to handle the high current values of some fast charging. JR radios all use a 3A fast blow fuse. This means that the enginneers that designed your radio were concerned that anything over a certain amount current would cause meltdowns. I would not put anything over 2 amps through a radio. The radio is designed to draw 200 mA, the charger charges at only 65 ma.

NiCads are supposed to be charged at 1 tenth of Capactiy. This is approximately that of the wall charger supplied with the system.

A reasonable fast charge is one times charge rate. Exceeding this rate is bad for the cells because the cells can not go through their chemical action quick enough, and they boil off, venting out some of their capacity. Quit buying expensive chargers!!! Buy extra batteries and charge them on your wall chargers the night before. Save money and have better results.


All this religious cycling people do is NOT good for nicads. They only need to be fully cycled occaisionally. The best way to dischage the TX battery is to leave the radio on with the antenna extended until the battery is down to about a volt per cell. Fancy dischagers will never do any better than this!!! Batteries stored over the winter (or long periods of time) should be at this dischagred state, and at room temperature. No cycling in the middle of the winter is needed. It is silly to do so.
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Old 08-27-2004, 12:03 AM
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Default RE: Transmitter pack charging?

Great info thanks. What does 1C mean by the way?
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Old 08-27-2004, 08:10 AM
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Default RE: Transmitter pack charging?

What does C mean? It is related to the milliampere hour capacity of the battery, i.e. a 600 mah battery has a C rating of 600 milliamperes, a 1500 mah battery would have a C rating of 1500 milliamperes or 1.5 amperes. Your transmitter most likely has either 500 or 600 mah batteries so C would be either 500milliamperes or 600 milliamperes if that is the case.
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Old 08-27-2004, 06:28 PM
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Default RE: Transmitter pack charging?

In other words, to charge a 1500 mAh battery at 1C is to charge it completely in one hour at a rate of 1500 mA. A 10 hour charge at 150 mA is 0.1C or C/10 and a 30 minute charge is 2C. It is generally considered that the 0.1C rate is kindest to the batteries. Although some might disagree, NiCds should not ever be charged at a rate greater than 2C (30 min) and NiMH should be no greater than 1C. (Note: charge times or charging current have to be increased by approximately 1.3 to 1.4X to make up for charging ineffeciencies in order to get a full charge)

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Old 08-30-2004, 10:31 AM
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Default RE: Transmitter pack charging?

It all comes down to following the MFG instruction or not.

Both the radio and receiver battery mfg tell you to charge at 1/10 C. So what constitutes a fast charge?

I usually charge using the supplied charger but sometimes I "fast charge them at 1/4 to 1/2 C so a 10 hour charge turns into a 2-4 hour charge.

I genrally avoid the problem by carrying a fully charged extra transmitter pack and an extra receiver pack. No fast charge needed.
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