fordman86

iTrader: (35)

I have three gp 3300 packs I got used. I am not getting 3300 out of them on a charge only around 2600 to 2900. But I get better numbers when I dead short them on my smart trays. I charge them with a ice and a mill. pro both at 4 amps. Is there any hope for them or do I need to start looking for new packs?

o.s. power

iTrader: (14)

charge at 5-6 amps

jbrow1

iTrader: (28)

They are fine. As you stated they take more charge when you put them on a tray. And depending on what amps you charge they will take more or less mah's into them. As said above charge them at 5-6amps (4 is fine if you prefer as well) and they will be fine. You don't really want to dead short them or take them down to zero though. Set your trays to .09 and call it good.

fordman86

iTrader: (35)

But shouldn't they be charging at 3300 or is that just for newer packs? So there ok for there age. I run stock truck and they seem to last the 5 min race and I have 2 4200's for the A main and when I run bad the other main I have to run.

jbrow1

iTrader: (28)

It also depends on what the peak detect is set at on your chargers. But if it's lasting the five minutes and you like the performance don't worry about it. I race with a bunch of 2 or 3 year old 3300's myself and they do the job plenty good enough for me.

fordman86

iTrader: (35)

On the mill. pro what is the peak detection for the nimh is you can't change it in that mode can you?

jbrow1

iTrader: (28)

I don't know anything about either of the chargers you said you have, you'll have to check out the manuals or find somebody who does. If you like the performance of your 3300's and the 4200's on the track, and the batteries are fairly warm when they stop charging then just leave it as is.
Sounds like everything is fine the way it is to me, getting 2900 into them is plenty enough. Any more and they may get to hot which isn't good anyhow and possibly pop em which definately isn't good.

Cain

iTrader: (294)

How do you do your charging process? are you traying them prior to charging them so you equalize all the cells prior to charging?

I know that if you don't do this, you may experience what you are seeing. I am seeing this with two stick packs that were race quality GP3300s when they were side by side but got set to starter box duty. They went from there 3500 mah common level to about 2800 mah.

Dead shorting as I have experienced will bump up your voltage (what you want for stock) but cut down your runtime. I always had two packs around that I deadshorted and they usually keep around 3300mah for awhile. Good packs.

If they are beater packs, I don't have a problem deadshorting. Good new packs should be good out of the box.

fordman86

iTrader: (35)

Well I start off by draining them in a 20 amp bulb discharger with cut off switch then tray them in my smart trays at .9 per cell but have messed around and went lower because had one cell in one pack that the light would go off right away but now after setting it to .3 per cell at .9 it stays right with the others and after that put them on a charger at 4 amps.

rc pro

cycle them it might help...

fordman86

iTrader: (35)

Thats what I been doing for the past couple days or track opens next week.