Batteries & Chargers Nicads, Nickel Metal Hydride, Lithium, LiPoly, Chargers, Cyclers, etc...

Nicad shelf life

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Old 10-30-2009, 07:27 PM
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Walther
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Default Nicad shelf life

What is the shelf life of a TX-RX battery that has never been charged?
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Old 10-30-2009, 08:09 PM
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Default RE: Nicad shelf life

Charge it and see what results you get. No way to determine what you ask.
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Old 10-31-2009, 12:17 AM
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Default RE: Nicad shelf life

I read an article by a battery expert (can't remember which one, but the author knew what he was talking about). He noted that even though a cell has not been used, it can still deteriorate over a period of years due to a minor leakage between the anode and cathode. I'll bet that the cells will still be good but the acid test would be to cycle them a few times, then leave the full pack on the shelf for a week or so to measure the capacity (i.e., give it a chance to self-discharge, if it's going to).

I'm going on several years on some of my packs, but I keep cycling them and testing them this way to verify that they'll keep holding a charge. That's why I give them that waiting period.

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Old 10-31-2009, 03:41 AM
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Default RE: Nicad shelf life

I have a TX pack from 1986 that still works OK.
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Old 10-31-2009, 07:24 AM
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I have had some that lasted for over 15 years and some that failed in less than a year. If storage was at low temperatures, the life is usually very long. Excessively high temps can degrade them quickly. Some tests that NASA has run shows that if they are stored discharged (with a shorting bar across the individual cells) at temperatures around 30 degrees F, they will last a very long time. I also had some wet NiCad's that lasted well over 20 years.
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Old 10-31-2009, 09:58 AM
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Default RE: Nicad shelf life

I have some NiCd packs that are over 10 years old and still in use. They cycle to near capacity and have good self-discharge rates. I have also had NiCd packs that lose significant capacity after only 3 years.

The 500 - 600 mAh AA packs that come with Futaba and Tower FM radios seem to always last many years. I suspect they are made from Sanyo's high-reliability cells. Higher capacity packs seem to have a shorter lifetime. All my 1100 mAh AA packs have lost capacity after 3 or 4 years.

You should test your pack for capacity and self-discharge rate. If you don't have the equipment or don't want to do this then I recommend that you just get a new pack. Using an old pack without testing if would be too risky.

There was an excellent web site written by a professional battery engineer that discussed NiCd lifetime. It was www.rcbatteryclinic.com. I think the website has been taken down. Maybe you can find it with a google search.
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Old 10-31-2009, 10:09 AM
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It all depends on how you use them. The more you charge them the shorter the life. A typical life is 300 charge cycles. NImh will last 1000 charge cycles. No fast charging. It burns the batteries fast.
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Old 10-31-2009, 11:10 AM
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Quote:
ORIGINAL: rendezvous944

It all depends on how you use them. The more you charge them the shorter the life. A typical life is 300 charge cycles. NImh will last 1000 charge cycles. No fast charging. It burns the batteries fast.
I don't think this is exactly true. In my experience it is shelf life and not the number of cycles that determines NiCd life. This may be because I don't fly enough to accumulate many cycles. I might charge a battery pack 20 or 30 times per year, so I don't accumulate enough cycles to wear out a pack. My packs seem to die from old age and not the number of charge cycles.

Storage temperature is very important. Storing packs in a refrigerator will extend their lifetimes. And I agree that fast charging is bad.

BTW, the usual rule of thumb quoted in the literature is 1000 cycle lifetime for NiCd and 500 cycle lifetime for NiMH.
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Old 10-31-2009, 02:36 PM
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Default RE: Nicad shelf life

Three seasons with Sanyo 1100mAh AA Nicds for 5 cell receiver and 8 cell transmitter packs and they're fading fast
These packs are always charged at C/10
Next season my glow powered models will have 2S A123 1100mAh packs[8D]

Pete
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Old 10-31-2009, 03:50 PM
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Quote:
ORIGINAL: rendezvous944

It all depends on how you use them. The more you charge them the shorter the life. A typical life is 300 charge cycles. NImh will last 1000 charge cycles. No fast charging. It burns the batteries fast.
I'm afraid you have it backwards. All the tests I have seen done by various labs and manufacturers show that NiCad has twice the lifetime of NiMh. Under normal use, these figures show about 1000 charge/discharge cycles for NiCad and 500 for NiMh. Also, the NiCad's prove to be more rugged; i.e. the ability to withstand minor abuse such as deep discharge, overcharge etc. NiCads still outperform NiMh in all respects except for energy density where most NiMh have a 20 to 40 % advantage.
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Old 11-01-2009, 09:47 AM
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Quote:
ORIGINAL: pilotpete2

Three seasons with Sanyo 1100mAh AA Nicds for 5 cell receiver and 8 cell transmitter packs and they're fading fast
These packs are always charged at C/10
Next season my glow powered models will have 2S A123 1100mAh packs[8D]

Pete
I had similar results with Sanyo 1100 mAh AA NiCds. I no longer use them. The lower capacity Sanyo NiCds last much longer in my experience.

For higher capacity I use NiMH. I'm trying Sanyo Eneloop 2000 mAh cells. So far they are holding up very well.
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