This may be better off in the battery forum, but the beginners forum seems to get the most activity and also gets some very interesting replies. So, here goes.

I have a Venim 1200mah NiMH 5 cell (yeah, 6 volts) batter pack. I put it on my Accucycle to cycle it through a few times and it seems to have topped off at about 978 mah, according to the Accucycle. These have a history of being off in the total discharge current, but this is a tad bit off the deep end. Charged to full at 978.. then..

I also have a Sirius Super Test discharger. It only discharges batteries. I was concerned about ths battery becaus I plan on using it in my Super Star 120. Actually, I plan on using two of them.

So, I put it on the Sirius Super Test discharger and, so far, it has discharged 1800 plus ma.

Is this a normal thing for NiMH batteries to be that much underrated? I mean 1200 mah rated but discharges to over 1800 mah. What's going on here? Just to preclude anyone chastizing the Sirius Super Test, it's new and has been calibrated.

CGr.

How deep is the Sirius discharging it? The mAh ratings can get a little misleading since different discharged voltages can be used to come up with it. The Sirius may be taking the battery down to a lower voltage than the Accucycle or even what the manufacturer used for the rating.

If I'm not mistaken, the Accucycle Elite uses a discharged voltage close to what most common receivers will still function at. I'd have to read the manual to verify that though.

On the same subject, I recently bought a number of 4-cell Spektrum 1100mAh ni-cad receiver packs and decided to charge and cycle each one. All of them have shown 1300-1400 mAh according to my Accucycle. I wonder if a conservative voltage was used by the manufacturer when rating the battery capacity? Most other batteries that I have bough usually perform slightly worse than their claimed capacity. We'll see if the Spektrums keep up this performance as they get used.

Which Accucycle (there are three versions)? If it is the Elite, you can set the discharge voltage plus lots of the other parameters. Set the discharge to 0.9V/cell and set the discharge current to 0.25C before doing your cycling. This will most closely match most manufactures specifications for depth of discharge and for rate of discharge. If either is higher than this, you will get reduced mah readings. Do make a full 16 hour charge at 0.1C prior to the discharge if you are comparing to factory specs.

CG,
If you have the original version of the Accu-Cycle, here's the thread for calibrating it. I did mine and it made a big difference.

Sorry, after looking at the thread again I see you seen it.

http://www.rcuniverse.com/forum/m_15...tm.htm#1526489

The elite is set to discharge to 1.1v per cell which is as low as any reciever will work for. It is set like this so you can get a rough idea how many flights you can get. To find out how many mah you battery has you need to set the discharge to .9v per cell which is as low as you can safely go with your battery. This will give you your full mah rating.

Austin

Gunfighter:

Thanks for that. I was looking for that thread, thought I had it, but did not. I also found this information in my archives today, I believe from the FAQ's from Radical RC, but not exactly sure where it came from.

I am going to calibrate my Accucycle tonite. By the way, it is the exact version you pointed out in that thread.

Thanks for that.

And, thanks to the rest of you that replied. Most helpful.

Acarter.. the version I have does not allow setting the discharge voltage. Only the # cells and discharge current rate. Thanks for the input, though.

CGr.

CG,
I did mine about a month ago thinking I had a bad battery, mine showed 277 on one side and 263 on the other.