Very good TimBle, your quotes from the manufacturers are right on. Fast charging with somewhat imperfect chargers (and most are imperfect in one or more ways) has ruined many a battery.

and trickle chargers are the most imperfect

Wasn't he actually quoting from Wikipedia?
In any case, this wasn't so much about charger performance but about servo current draw.
My point was that high capacity AA cells, in the main, are not intended for high current applications and I know from my own work with them that high currents and/or deep discharges will degrade AA cells in a very short time. For instance, I have logged a 20% reduction in capacity after 2 discharges at 0.5C to 0.25V from one (mainstream) manufacturer's type.

the quotes are from Wiki who took them from battery manufacturers and consolidated the info. The facts stands, the charging a NiMH at 1C through a high quality charger using delta V program is the preferred method of charging these batteries and prolonging their life.
Slow charging also raises the temperature of the pack and for a longer time which also has a degrading effect on the cells.

The moral of the story is use a high quality charger and do not exceed 1C charge rate.

trickle chargers are great for "waking Up" battery packs after a few months of no use and thats exactly what I use my Futaba supplied TX/RX battery charger for and my batteries suffer no ill effects.

More often than not, the battery manufacturers know more about their own products than the people on internet forums... :/


glow fuel manufacturers, well thats another story...

The article, like you, does not even understand the difference between slow charging and trickle charging. A slow charge rate is C/10 ma and is what most wall mount chargers are designed for. It will fully charge a battery in 15 hours. It is a low enough charge rate such that it will not damage a batter if you leave it on longer unless it is for many days. A trickle charge is C/50 ma rate and is designed to just replace the charge lost through self discharge which both NiCad and NiMh batteries experience. Since they maintain the current charge of the battery and do not over charge it, there is no way a trickle charge will harm a battery. Like I said earlier, I charge at a slow rate when returning from flying for 15 hours and then switch to trickle charge until I next go flying. That way my batteries are always ready to go and they last for many years. If you are confortable charging and a 1C rate that is fine but I sure do not see any one else recommending that as a regular pratice.

Bruce

yawn

Bruce

That goes opposite to my understanding of NiCads or NiHM. You "wake them up" with a peak charger. Even better to cycle them if they have sat around a while. Nicads self-discharge at 15% and NiMH at 20 to 25%. Trickle chargers are good to keep a battery "topped off". Also called a "float charger" for that reason. You charge them rapidly (1/2 to 1C) and then maintain the level with a trickle (1/10 to 1/20C).

I have mine on trickle chargers on a timer for two hours a day to keep them ready for use when I get an opportunity. I plug a 12 outlet strip into a HD appliance timer set to switch off at the hour I leave work. Once a month I cycle them twice with a fancier charger/discharger.

landeck was correct in differentiating between slow chargers and trickle chargers. Of course, a charger can be both, switching from slow to trickle, but the 2 conditions are not the same.
It is quite valid to say that older generations of NiCd and NiMH cells could be charged at 1C and they would be quite happy with this, providing end of charge is managed correctly.
However, it was posited that the answer to battery life reduction caused by heavy current draw is to use higher capacity cells. I maintain, and I do know what I'm writing about here, is that modern high capacity NiMH cells are much more fragile than older cells. The increase in capacity is brought about by using thinner etched metal foils for the electrodes. By being thinner, the foils cannot accept currents as high as lower capacity foils without being damagingly heated. Low self discharge NiMH cells will lose no more than 25% capacity in a year, which is fine for a digital camera, pointless for RC applications, and they are even more sensitive to current draw, as I have found.
My experience of dealing with battery manufacturers is that they know only about 1/4 as much about their products as they ought to, and then they won't tell you what's really going on because it's commercially sensitive. So you get the same old drivel about "Charge at 1C until the end of time" because that's what GP batteries say, about everything.
I asked for capacity maintenance information from GP four months ago, for a professional application.....dum de dum de dum, .......still waiting. You need to take manufacturers' recommendations about fast charging under advisement; one thing is sure: if you use a slow charger and turn them off after 14 hours, you won't damage the batteries.

So, I will be charging my packs on a slow charger and turning then off when they're charged