jeffk
06-29-2007, 04:16 PM
I've got a TP 2100 mAh 3s 15C pack for my heli. It's not my only pack, but it's the only one I've used so far. There are about 4 cycles on it and I'm concerned that it's not quite right.
I've never gotten more than 5 minutes of runtime out of it before I noticed the motor sound change slightly and I landed immediately, but I didn't think too much about that because it was new. I figured runtimes would increase. No 3D (noob!), just basic hovering. Whenever I bring the heli in, the battery is pretty warm. I've got another pack just like it (still unused) and the questionable one MIGHT be a TEENY bit fatter, but not enough to really tell and I don't think this one puffed yet. Today I had the heli up for about 4 minutes and brought it down. I measured the pack temp at 138 degrees. The motor was 137.
I've always let the pack cool for at least an hour before recharging, and I've never charged it at more than 2.0A (which isn't quite 1C) on a Common Sense balance charger.
The charger is showing that the number one cell is lagging behind the other two. Today when I connected the pack to the charger, it showed 3.1v for cell one and 3.4 for the other two. Under load, I'd imagine that cell would have dipped below 3.0 and could be why it's running hot. Again, this is a fully charged pack after only 4 minutes or so of flight.
The heli is mechanically fine, and the gear mesh is not too tight, nor is the tail drive belt. The bearings are all good too. A hand spin nets several free rotations before stopping so I don't think there's any binding going on.
Should I request an exchange or am I being overly paranoid? The pack is less than a month old and I'd have expected better performance out of this, especially considering that It's a TP and I didn't think I skimped on price...
I've never gotten more than 5 minutes of runtime out of it before I noticed the motor sound change slightly and I landed immediately, but I didn't think too much about that because it was new. I figured runtimes would increase. No 3D (noob!), just basic hovering. Whenever I bring the heli in, the battery is pretty warm. I've got another pack just like it (still unused) and the questionable one MIGHT be a TEENY bit fatter, but not enough to really tell and I don't think this one puffed yet. Today I had the heli up for about 4 minutes and brought it down. I measured the pack temp at 138 degrees. The motor was 137.
I've always let the pack cool for at least an hour before recharging, and I've never charged it at more than 2.0A (which isn't quite 1C) on a Common Sense balance charger.
The charger is showing that the number one cell is lagging behind the other two. Today when I connected the pack to the charger, it showed 3.1v for cell one and 3.4 for the other two. Under load, I'd imagine that cell would have dipped below 3.0 and could be why it's running hot. Again, this is a fully charged pack after only 4 minutes or so of flight.
The heli is mechanically fine, and the gear mesh is not too tight, nor is the tail drive belt. The bearings are all good too. A hand spin nets several free rotations before stopping so I don't think there's any binding going on.
Should I request an exchange or am I being overly paranoid? The pack is less than a month old and I'd have expected better performance out of this, especially considering that It's a TP and I didn't think I skimped on price...