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View Full Version : recording discharge rate without intelligence?


knightrider
2011.01.02, 09:31 PM
Is there a thread somewhere, or is it possible, to find the discharge rate of a AAA without buying an electronic discharger, like the one MuchMore makes? Maybe connect the battery to a resister and monitor it w/ a meter or something like that?

I'm wondering if the 60 bucks for an electronic discharger is worth it since once you learn a particular battery, you don't need to put that battery back on the unit. Like me, I only have 16 batteries, having something like that may be overkill. Thanks!

EMU
2011.01.03, 09:11 AM
In general, a discharger is used to train the cells to release their energy quickly. You train the cells by discharging, not see how well the type of cell discharges. This is primarily useful for slow motor classes (70t, 80t, etc). I use the Novak Smart Tray SE, which discharges at 3A. You can find them used on ebay for a good deal.

knightrider
2011.01.03, 10:05 AM
I guess this is one of those things where each person has a different preference. You and I race with some people that beleive in matching the batteries by their discharge rate. This product shows that rate and allows that kind of match, http://www.muchmoreusa.com/dischargers/mmrp1020.html

I was just wondering if I could do it with a certain type of resister and V meter.

bermbuster
2011.01.03, 10:59 AM
I guess this is one of those things where each person has a different preference. You and I race with some people that beleive in matching the batteries by their discharge rate. This product shows that rate and allows that kind of match, http://www.muchmoreusa.com/dischargers/mmrp1020.html

I was just wondering if I could do it with a certain type of resister and V meter.

What they are doing is trending the discharge capacity.
If you discharge at 3 amps and you get 590 sec.
That may cost you the 10 minute main....
If your getting 700 seconds those cells are awesome.
If you only race 5 or 7 minute mains the 590 sec cells are good...

The muchmore discharger used to be $130...if it is now $60 get it while you still can.....

EMU
2011.01.03, 12:12 PM
Rate and capacity are two completely different things... Rate = current. The MuchMore unit is fixed at either 5A or 30A. For Mini-Z use 30A is way too high, and you will deplete the cells in a matter of seconds. 5A is still a little high, but the cells will release power consistantly, and wont slow down as much before they completely dump.

bermbuster
2011.01.03, 12:59 PM
Rate and capacity are two completely different things... Rate = current. The MuchMore unit is fixed at either 5A or 30A. For Mini-Z use 30A is way too high, and you will deplete the cells in a matter of seconds. 5A is still a little high, but the cells will release power consistantly, and wont slow down as much before they completely dump.

In the realm of discharging they work together.
Your discharge rate is fixed 5 amps.....it takes a certain amount of time to discharge to a cut off...thats your capacity.....
The reason matching works the best this way is you are testing your cells under a load (amp draw)
The trick is to know the magic number for voltage drop off.....;)

EMU
2011.01.03, 02:03 PM
I just picked up a MuchMore CTX-D2 for $40 shipped on e-bay :)