>> Do you suggest making your own battery packs, or buy them already soldered? <<

Buy them pre-made. They don't cost much more than making them yourself. If you defray the shipping cost over 2 or more packs, you can't make them much cheaper than you can buy them.

Try Mr. Nicad at Batteries America. Make sure you tell them it is a motor power pack so they put the right leads on it. They will also put the connector of you choice on for not a lot more than the cost of the connector. They also make them in a variety of configurations. See their ads in the mags and the web site.

Soldered connections are better if they are done properly. But it is very easy to damage a NiCad cell unless you really read up on it. Save yourself the hassle.

>> What type of cells/packs should I start with, and what should a good pack cost to buy/build? <<

It depends on the size of the plane. If it is a 16 oz or lighter Speed 400 powered plane, you will probably be limited to 500AR or 600AE packs by weight and physical size. The AR's are higher discharge rate and the AE's last longer because they don't have as high a discharge rate. BTW, the A refers to the diamter of the battery cell, as in AAA, AA, etc. One confusing one for me every time I see it is SCR. As an EE, I think electrical component, but what it actually means is Sub-C high discharge Rate. Sub-C's are a little smaller in diameter than C cells.

Read this article and then visit The R/C Battery Clinic .

>> What are zapped cells? <<

Applying a very high current to a cell for a very short period of time allows the cell to discharge at a higher rate. I believe it is because the resistance of the cell is lowered slightly.

It is only worthwhile for cells with a certainly amount of mass which is usually related to the storage capacity.


I'll add one of my own

>> Can I use NiMH batteries in a Speed 400 pylon plane? <<

Not if your primary goal is speed. Endurance, yes. Speed, no. NiMH's don't handle high discharge rates well. They get too hot and are permanently damaged. When I first started flying Speed 400, I bought 3 packs: 7 cell 600AE, 7 cell 500AR, and a 8 cell 550 NiMH. I tried the 600AE. It stayed reasonably cool and lasted about 5 minutes. The 500AR lasted about 3-4 minutes and was faster, but was pretty hot. I started to try the 550 NiMH, and I was ready for the hot rod output of an extra cell, but the power output was audibly much lower, so it never got flown in the pylon plane. It gets used in a park flyer instead.