Rx Battery Pack testing?

[Plaidfish]

Anyone have a reliable way to check battery packs?
I have 2 packs that I had short out...one was via a servo shorting out through the RX...and the other I had a plug in the pack lead and they shorted out just long enough for the wire jackets to melt a little....not a lot and not enouhg to let them stay shorted out....once I removed the lead for the charger it stopped shorting out.....I hate to have to toss them cause both were brand new and I only had 1 day on each of them...ar ehtey worth saving and is there a good way to test them????
I have a duratrax Ice charger so I can ge tpack data from that but I'm not sure I'm reading everything right.....any advice from the RCNT pool o KNowledge is appreciated...
Thanks
Eric

 

[jon2]

I think you are fine. A better way to find out is to have them apart and fully charge them and then discharge them. See which falls out first or see which doesn;t charge correctly.

 

[FastEddy]

Does your charger have adjustable discharge rate and a discharge timer?
If so cycle them a few times and watch how long the discharge takes.

 

[beason]

i would guess if it would hold a charge.. and keep a decent voltage under load.. it would be ok.. (keeping a charge would signal if it was shorted internaly, and voltage under load would signal a shot cell)

 

[Plaidfish]

cool thanks for the quick reply guys....
Jon:
do you mean take every cell apart and do them individually? and should I charge them at 1.2V at like .5A

Eddy:
Yes it does....I usually charge the packs to 6V at .7amp and discharge to .9V @ 1A....I'm not sure if it's the correct settings cause I get different answers every time I ask what people set their stuff to at the track....I figured this were good base settings w/ a little quicker charge rate than usuall so I can do 4 packs in one night and not be waiting 5 hours for every one to finish......
Beason:
the Only way I can test under load is to break the shrink wrap on my pack and every time I've done that in the past they turn to crap on me......I guess I'll just have to bite tthe bullet and re-shrink em, Huh?

one more thing....when my pack is done charging I almost never see the current rating at what the pack is....does that mean I had a false peak?
and do I need to re-peak or should I discharge and then charge it again?
I know I got the settings from you guys before but I'm still learning how to read my charger...it's funny I can design a system that I decide what type of signal to use and how many counts of resolution tat siganl need s to be sliced into to give a value for different variables in an HVAC system but Ican't understand my Battery charger...I need a degree in Battery technology for this thing....LOL
thanks for the tips guys I'll give it a try tommorow nite and see how I do.....

 

[beason]

why do you have to un wrap??

 

[jon2]

cool thanks for the quick reply guys....
Jon:
do you mean take every cell apart and do them individually? and should I charge them at 1.2V at like .5A

It is more anal then really needed. It is just a suggestion to get a more accurate measurement of each cell charge and discharge rates.

ED's method is easier.

 

[Plaidfish]

I got ya^^^

Beason I use the XS power packs ant they are all covered, I can only get to the pos/neg on a battery if I break the wrap a little...once I do it the shrink wrap he uses just falls apart quickly....if I leave it they tend to last a long time....is that not normal?
I ust ASS-U-MEd it was...

 

[FastEddy]

I would just test the pack as 1 unit.
Figure out what the draw is of all your electronics under driving conditions and set your discharge rate as close as possible. Time the discharge. If your comfortable with the outcome, your set. If not, you can tear the pack down and find the dead cell. or just poop can it and get another. I have got some good RX packs from flea-bay for under 20.00. How much time do you want to spend?

I call this real world testing.

 

[Plaidfish]

I agree....I was hoping there was a more sure fire way like what you were discribing...I have gotten packs that seem to be charged fully but don't last for chit.....my digi meter is shot right now so testing is difficult to say the least....I have 2 Fluke 87RMS meters and both crapped out on me now....AAAAGHGGHHHH....

 

[beason]

you can get the the leads on the plug.. thats where i check mine at.. at the plug that plugs into the swich..

 

[Plaidfish]

OH...that's why..I don't have a switch hooked up....I run it hot-wired.....I'll set that up so I can test it...thanks