I am putting together a GP Extra 27% and was getting some stuff at the store today when i started looking at batterys for the EVO ignition that can run on the 2cell lipo. The store owner said Fromeco. Are they any good. This will be my second gas but first 3d gas plane. Any help would be great!


They were costly but i have learned that does not always mean better!!!

Nowadays, with Lipos going to 30C discharge rates, practically all lipos have at least a 10C rating.1C is the capacity of the cell i.e if its 1500mah then the discharge rate at 10C is 15amps.Your CDI will draw much less than 2amps at full power so theres no need to purchase an expensive lipo with a higher rating than 10C. I would go for a 1500~2100mah cell rated at 10C which you can mail order for less than $20/-.

Fromeco is probably as good as you'll get if you're going to run Li-Ions.

Be aware if you're not already, that there is a difference between Li-Ion and Li-Po batteries. Li-Ion is usually for radio or ignition systems and Li-Po for electrically powered models as the Li-Po can put out a lot more power than the Li-Ion. The downside is that it's a volitile chemistry and must be treated accordingly or you'll get a nasty surprise in the form of an explosion/fire. Both battery types usually require a regulator, although some engine manufacturers are now supplying modules that can take unregulated Li-Ion or Li-Po batteries as you mentioned.

That having been said; ditch the Li-Ion or Li-Po options for your gasser and go to the new A123 batteries. Those can put out more power than Li-Po's, won't explode, can be charged in 15 to 20 minutes if your charger can put out that much power and don't require regulators as they have a slightly lower nominal voltage.

A123's are both a company and specific chemistry/construction which is patented. They are a Lithium/Iron nano phosphate technology and are NOT the same as the Li/FeP04 batteries you'll see around as well. Some vendors are saying that these are the nano phosphate technology but are not. To tell the difference, look at the C ratings as the Li-FeP04's are 10C while the A123's are 30C and can burst to 60C.

That's a brief explanation, if you're interested do a few searches as there are a lot of threads and information posted about A123's now.

92s,
I have no experience with Li-Ions or Li-Po's. In my 28% Edge with a ZDZ 50 I went from NiMh cells to 123 cells. It has a 2300 (DeWalt) for the airborne electronics and an 1100 (B&D VPX) for the ignition. I would never go back, the 123 cells are so easy to deal with and the rapid recharge, without deleterious effects on the cells, means you can fly as many flights as you please. Just recharge while you are taking a break or refueling.

There is a lot of information in here about using a single 2300 pack (two cells) to power bothe the ignition and the on-board electronics. I have no experience with that, but the people who do seem to be very pleased with that method also.

The packs are very easy to make and the cells are readily available. Probably worth giving these cells a little consideration.