Piccolo Batteries
So far I have tried a few different types of battery for the Pic.
First the standard pack, tends to be supplied with the Piccolo all-in deals. 250mAh AAA x 7 cell nickel cadmium, or nicad. Flight times typically 4 minutes, depending on weight and efficiency of the helicopter, and the state of health of the pack.I get about 4 minutes from my Sanyo pack, I believe it is a not-so-good example as I am using a brushless motor and expect longer flights. However it seems happy to plod on, accepting a 1 amp fast charge without getting hot. Here's a photo:
By the way, the connectors are 2mm gold plated plugs and sockets, widely used for small electric flight models and probably useful up to 15 amps. I got these particular ones through my work, but they are available through specialist electric flight suppliers.
Next I have some packs of 350mAh 1/2AA x 7 nicad. Flight times typically 5.5 minutes, these are a little heavier. They are cut from some welded 12 cell packs bought from Hillcott electronics, and the cells are marked N350AAC. Happy to fast charge without getting hot, I have gone up to 1.5 amps charge so far. I believe the extra weight would drag down a standard motor Pic somewhat, I seem to remember lending a pack to someone and confirming this. Ah yes, Colin's Hughes 300 at Dewsbury.
I usually fast charge my nicad packs on a Robbe Infinity charger just before use. If I am short of time I can charge 3 packs of 350 nicads at the same time, connecting them in series.
720mAh AAA x 7 NiMH (nickel metal hydride). Flight times 9-10 minutes. This one used to be an 8 cell pack like the 250 above, but with another cell along the bottom. In that form I had flights around 11-12 minutes. These are good cells, bought from Overlander, but not cheap, £22 for the pack. The eighth cell was removed when I started reshaping my packs to suit the Bell 47 style undercarriage, it was easier to simply remove the cell than to rewire the whole lot! Anyway I thought the experiment needed doing. The standard 295 motor may not do well on 7 x NiMHs as the cell voltage drops under load more than the nicads do.
"550mAh" AAA x 8 NiMH. Flight times 12 minutes! These are the "famous" Camlink cells from Asda supermarket, and certainly don't act like 550mAh. As I write this the cells are on sale for £4.94 per pack of four, intended for use in calculators, remote controls, toys and portable electrical goods. This means I have to make up the packs myself. The "seven + one on the end" configuration of the pack is mind boggling to wire up, but necessary to fit in the Bell undercarriage if I wish to keep the pack near its original shape and position. I really like these cells! There is a drawback or two to long flights, one is the sheer effort of concentrating for so long (especially if your flying is as bad as mine!). It leaves the hands sweating. The motors get hotter, undoubtedly leading to shortening of the tail motor's life, mine seem to be lasting about 100 flights each. I let the motors cool a few minutes after flying a NiMH pack.
I try to keep the charge current down to 600mA for my NiMH packs, so they don't get too hot on charge. This is obviously an inconvenient rate to charge at a flying session, so what I usually do is charge them at home, then top them up at the flying session just before flying. I am presently charging my NiMHs on a Jeti mini charger. Both this and the Infinity mentioned above share a 13.5 volt 3 amp switched mode power supply, running from the 240volt mains.
Suppliers:
Camlink cells from - Asda! Look for the battery display, blue and yellow packs.
Update! The Camlink cells are no longer available but Maplin electronics suppliers are selling an even better cell, the Vanson 750mAh, they have even had them on special offer a few times, 2 packs for 1, making 8 cells for £6.99.
Latest! Flying with some 2 and 3 cell Kokam lithium polymer packs - big increase in duration, decrease in weight. I'll do some pictures soon.
Overlander