PDA

View Full Version : Puffed pack??



forescott
12-16-2010, 10:34 PM
How do you know if a pack is puffed? Mine looks normal but it feels as though it has a slight bit of air between the shrink wrap and the cells. My hyperioin charger wont charge it, and says "low voltage, check pack"

GP73
12-16-2010, 10:54 PM
It could be the wires, a puffed pack would be... well... puffy! :lol:

Check the video:

http://www.youtube.com/watch?v=7JkMTBiXJFY&feature=related

forescott
12-17-2010, 12:56 AM
I cut the connectors off and put them in a bucket of water, then read a post from another member saying to charge them for a couple of minutes in nimh mode to bring the voltage back up. So I ran outside, took em out, removed the shrink wrap and blew em out with compressed air. Soldered the connectors back on and put one on nimh charge for 5 minutes. Now its balance charging in lipo mode!! Yikes!!!

Fluid
12-17-2010, 08:26 AM
You probably did the right thing. Putting the packs in water for a few minutes probably did nothing - you need to add some salt to the water to speed up the discharge.

You told us nothing about the packs or their history, but it appears that at least one cell was under-volted due to over-discharge. Even if the pack charges fully, keep an eye on it to make sure it does not do this again or worse actually puff. Try to find out why this happened, particularly if it was due to abuse.



.

blackcat26
12-17-2010, 08:50 AM
When you gonna listen to me Scott........

forescott
12-17-2010, 05:39 PM
I think the lvc on the proboat esc wasnt working correctly. I programmed it with the programming card once, then again yesterday. The second time I programmed it I got a different set of beeps when I turn on the esc. First time I got one beep, followed by a set of 5-beeps. The second time I programmed I got the same configuration of beeps, but instead of single beeps, I got sets of three beeps? I'm thinking the lvc didnt kick in the first time I programmed the esc and the Batts over-discharged. These packs were turnigy 3300mah 4s 30c, about 6 months old with about a half dozen runs, so they were relatively new. Good news is one lipo took a charge last night, unfortunately the other one I could not revive today. Gave it about ten minutes on nimh charge, and took a lipo charge for just a couple of minutes before the charger shut down. It was a little warm too. Not sure if I want to mess with it anymore.

forescott
12-17-2010, 05:40 PM
When you gonna listen to me Scott........

This thread is dedicated to you buddy! You saved me a 4s pack!! :bowdown: :hug1:

igottalongone
12-17-2010, 10:22 PM
Once a pack does something "sketchy" I run it through a few cycles under load to make sure it doesn't burn my boat to the water line the next time I run it. You need to build yourself a discharge tree.. I believe your running a 4S pack, go on e-bay and find some 15v bulbs. The last ones I bought were 150watt ,15v bulbs and I got them for $2 per w/free shipping... Just solder 6 of them in series along with whatever connector you use. Hook your pack to the battery side of your watt meter and the load side to your discharge tree.. You can now see how fast the voltage drops, amps your pulling, watts your making, etc.. This will tell you tons about the pack. If you can cycle the pack a few times under a load and no puff, numbers stay good etc, it may be fine.. But, If you "trick it" into taking a charge and then run it without testing it, your totally rolling the dice... Bad news on the bench is always better than bad news at the lake... The discharge tree is also handy for the times you charge a pack, but can't run it... Makes discharging it at home quick and easy...
Ron

forescott
12-17-2010, 11:48 PM
Cant you discharge a pack on most chargers too? I think my hyperion does that.

igottalongone
12-18-2010, 12:54 AM
Using the discharge feature on your charger is (a) hard on your charger... the internals get very hot during discharge... (b) painfully slow... the charger cannot discharge too fast, if it did it would burst into flames, lol... (c) most important, it won't put a load on the pack...
Ron

sailr
12-18-2010, 11:26 AM
It takes forever to discharge a pack with a charger. I set up a discharge station. I mounted a large outrunner motor with 16" airplane prop to my workbench. I set up with a watt meter between an aircraft esc and the battery and also a volt meter plugged into the balance plug so I can read each cell. I use an airplane transmitter/receiver so I can set the throttle at any position and just let her run while I monitor the pack condition. I can discharge a pack in a couple of minutes down to storage mode, etc. I watch the amps it's pulling and the volts in each cell. Just remember, when you take the pack off, the volts in each cell will go back up a bit.

When I go run I carry about 20-30 packs. Sometimes I don't get to use them all for various reasons. Putting them in storage charge state has been a royal pain until now.