HeliStyle

My Feedback: (2)

I got a new charger with a power supply yahhhh lol I got the turnigy accucell-6 it looks like a pretty sweet charger, charges lipos, nimh, nicad and such packs.

Could someone explain what acouple of things are as far as functions on a such charger?


1. What is discharging a pack? and why or what is it used for?


2. What is auto cycling a pack mean or cycling a pack? why or what is it used for?

3. And would I be using these two fucntions on lipo's or just nimh and nicad packs mostly

thanks in advance everyone

Clay Walters

Some battery chemistries develop a "memory" in that continual charge & discharges less than complete cause that battery to not develop a good charge after charging. The term "charge" is multipurpose - both voltage and available amperage are implied.

Transmitter batteries have a lot of "charge" remaining in the pack even though it drops below the necessary voltage capability to support the electronics in the transmitter. So we recharge the battery at that point. A lightbulb would have been happily burning for a good while to go but we can't wait that long because we need the voltage higher to support the electronics. You might consider that this means we are "teaching" the battery its low when it actually has a lot left in it.

Cycling the battery completely discharges down to a lower level (on some chargers you can set this) and then recharges up to full. A few cycles can often return the battery to a higher level of performance.

I know NiCd's benefit from this every now and then and believe NIMH batteries do when they are new but not so much once a good "forming" charge has been established. I cannot say about LIPO's as I have no experience with them.

Hope I've imparted a useful concept,

Clay

HeliStyle

My Feedback: (2)

thanks for the explanation

so when I cycle a nimh, its alright to discharge it to nothing then charge it up full?


Also I heard people say not to discharge a lipo/ or auto cycle it, is that true?


Another question is they say it has auto balance when discharging a lipo, so does that balance out all the cells to 3.7 volts on a 3 cell lipo and charge it to its max capcaity?


Sorry im new to a nice charger, I have been using the stock wall lipo chargers that come with rtf models lol


thanks

KW_Counter

Do not discharge to -0-.
It is recommended to about .9 volts per cell on NiCd and NiMh.
There is a lot of controversy about battery memory.
I don't have the definitive answer but believe they still suffer from this effect.
Not as badly as in prior years but still somewhat.
The other reason to discharge and charge is to check the capacity of the battery as compared to the label.
When you can only put in about 75% of the rated capacity it is time to retire the pack,
or put it to work in a low critical application like your electric toothbrush.
Good Luck,
KW_Counter

Rodney

Check out www.rcbatteryclinic.com for some good reliable advice on how to care for your batteries, all types. On NiCad, it is okay to discharage a single cell down to 0 volts, in fact this is NASA's preferred way of storing them (they also place a shorting bar across each cell while it is in storage. On NiMh, I am not so sure but some say it is not wise to take them all the way down to zero. What will hurt either NiCad or NiMh is a reverse charge. While it is okay to deep discharge a NiCad as a single cell, it two or more are in series and you deep discharge them, the weaker one will be reverse charged to some extent and that will most probably harm it. You will find NiCad more immune to damage from minor abuse than NiMh plus NiCad will provide you with twice as many charge/discharge cycles and will have a slightly lower internal impedance than NiMh. Do not worry about the so called memory on NiCad's, it just does not happen the way they are used in our applications. Now both NiCad and NiMh can suffer from voltage depression which some mistakenly call memory problems. This is where the crystalline structure reforming within the cells during the charge/discharge cycle is larger than desired and is usually corrected by a long slow charge (charge at 0.1C for 16 hours) and both NiCad and NiMh will benefit from this slow charge (some times called a forming charge) occasionally, especially after being fast charged a number of times or after having been in storage or inactive for a few weeks or months.

HeliStyle

My Feedback: (2)

thanks for the response, I will deff read the link you included, I'm new with these kinda chargers and don't really know where to start on a charger like this lol

JohnMuchow

HeliStyle
I have some NiCd/NiMH info on my web site at http://www.camlight.com
Check out the Why Discharge? and Tech Tips sections.

Capt Lou

Helistyle:

Inaddition to the above information, look at this web site: www.batteryuniversity.com

Capt Lou