Another Battery question from a newbie

Sorry to bore everyone but I am just about to learn about nicads and charging the hard way....

I have/had a Sanyo 9cell 250mah NiCad pack which in my extremly excited state of trying to get beyond the hover managed to charge at 6amps...
only took 5mins... then I noticed the pack stayed hot for ages and there was a popping noise or 2....
After allowing to cool I took the heat shrink off and noticed some but not all of the cells have a rusty end (i assume this is where the gas vented) is there anyway of telling if all the cells are blown or not?

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[rdn1153]

You would have to measure each cell individually to understand their state. How old is the pack? It sounds fried. What are you flying with a 9 cell pack anyways? That's seems like a pretty hot voltage.

the pack is very new under 10 charges discharges, the owner of the shop I bought the pic from suggested this pack, whaddaya reckon I should use? its pretty much a standard FP with standard motor and a pic plus board.... how would I verify each cell?

Standard packs are either a 250mAH 7 cell Nicad or an 8 cell 730mAH Nimh pack - go for the Sanyo ones.

Nicad = less weight, quicker charge, short flight times
Nimh = more weight, slower charge, longer flight times (as long as the heli is at minimum weight)

I charge my Nicad at about 500mah (0.5amp = 2C) for about 30mins or the Nimh at 700mAH (0.7amp about 1C) for about 1hr.

Regards,

James

[rdn1153]

If you only had 10 cycles on it, I'd think it should still be under warranty and was probably a shorted cell in it. To verify each cell, you'd have to take the shrink wrap off and measure the voltage of each individual cell, but that may void your waranty, so try returning it to the dealer first.

Typically you add 1 cell for NiMh over NiCd, so try either a 6 cell NiCd about 650mAh or a 7 cell NiMh about 720mAh. Go with a proven cell in the Piccolo, a lot of batteries can't deliver the amperage necessary even though the rating is adequate. The cost of Lithium batteries has really come down, you might consider them although they do require a special charger. ,

ps. don't go for the 600mah nimh - i am hearing bad things about them