discharging Tx pack? - RC-Monster Forums

tallyram · **discharging Tx pack? -** 11.07.2006, 11:56 PM

my ice charger won't discharge my Tx pack in my spektrum dx3. im using 8 venom 2400 AA's. please help!

BrianG · 11.08.2006, 12:06 AM

Dumb question: Are you hooking the connection up right? The end of the Spektrum pack looks like a 9v battery. A lot of chargers won't even read the voltage on the battery if hooked backwards - my Hyperion 7i is that way.

Out of curiosity, why are you trying to discharge them? It's not like they need to be conditioned like you would for running an R/C motor. The Spektrum transmitter probably draws between 100-200mA (0.1-0.2A) max so the benefits you get from discharging aren't as apparent. Because of this, I charge those AA's at 0.2A max unless I'm in a hurry. I'd rather have a long "runtime" out of them then a peak voltage that may drop quicker...

tallyram · 11.08.2006, 12:17 AM

i'm using the adapter that came with the spektrum. i put a deans connector on it and plug one end into the Tx and the deans onto the charger. reason for discharging is that i have had these batts for 6 months without use. they only charged for like 5 minutes before peaking? tried repeaking, lasted 5 minutes again. i wanted to discharge and then charge to get a baseline. what do you suggest?

BrianG · 11.08.2006, 12:27 AM

Hmm, maybe one cell was overdischarged and now is too low? Are all the cells about evenly warm at the end of the charge? They should be. If one is cool, then it may be bad.

You could try charging at the lowest rate you have on the charger for a VERY long time and see if that doesn't wake them up.

If you have a 10ohm resistor (1/2 watt), you could use that to discharge each cell. Just keep a voltmeter on it so you can monitor the cell voltage. Once it gets to about 1v, go on to the next one.

tallyram · 11.08.2006, 12:33 AM

i'll try charging at .1 amp. btw, i have an ice charger. any more suggestions?

BrianG · 11.08.2006, 12:57 AM

Not that I can think of.

I think GlassDoctor has a couple of ICE chargers, maybe he can suggest something specific to that charger...

MetalMan · 11.08.2006, 01:01 AM

Have you played around with the cutoff point? You can mess around with that, and see what the results are. Once (if) you get that, then you can have the ICE cycle that pack a few times, to "wake it up."

tallyram · 11.08.2006, 02:12 AM

thanks for the suggestions guys. its been charging at .1 amp for about 95 minutes. hope slow charging helps. if not, i'll try playing around with the settings again. thanks again!

BrianG · 11.08.2006, 02:16 AM

Are you charging through the Spektrum's charging jack? If so, don't. It doesn't seem to work so well because I had issues too. There must be other circuitry in there. Remove the pack from the radio and you will see the "9v" connector on the end. Use clips or something and charge from there.

coolhandcountry · 11.08.2006, 09:45 AM

I tried to discharge on the tx as well. It seems like it has a diode or something that allows current to flow one way. I can charge no problems but couldn't discharge.

BrianG · 11.08.2006, 10:35 AM

I actually added another charging jack at the top of my DX3 and wired it up directly to the battery connector. This works a lot better, but does void your warranty. Simpler to just remove the pack...

tallyram · 11.08.2006, 01:25 PM

i'll try removing it and using clips. thanks for the help guys!

brian, your speed calculator is on the money with my brushless g2r. i had it shot numerous times with a radar gun and it read 48-49mph every time. your calculator estimated 48.7mph with all the correct info entered. super job, it will help lots of people out. thanks again for putting so much effort into it.

BrianG · 11.08.2006, 01:42 PM

Quote:

Originally Posted by tallyram

i'll try removing it and using clips. thanks for the help guys!

brian, your speed calculator is on the money with my brushless g2r. i had it shot numerous times with a radar gun and it read 48-49mph every time. your calculator estimated 48.7mph with all the correct info entered. super job, it will help lots of people out. thanks again for putting so much effort into it.

Instead of using clips, you could make an adaptor by getting this to snap on the battery pack. Just a suggestion.

I'm glad the calculator is that accurate. As you can see by the number of pages/posts in that thread, it's been through a lot of revisions to get it that way! Thanks!