Greg Covey
Posts: 4383
Joined: 5/24/2003
From: Rochester,
NY, USA
Status: online
|
Mitch,
One of the hidden characteristics about all Lithium cells (Truth vs. Marketing) is that if you push them beyond their rated continuous current, you greatly reduce the lifespan of the cell. Unfortunately, many manufactures will not publish cell cycle data per current draw and use attractive marketing techniques to sell their product. As an employee of FMA Direct, I can tell you that only Kokam cells will have this type of data made public.
Keep in mind that the same thing is true for NiCd and NiMH cells. The recent testing on the new 2-cell Scorpion system in the R/C car world has simply blown every existing battery technology away. Look for these results to be published in Fly RC and R/C Driver magazines. The typical NiMH car pack lasted about 20 cycles and the Scorpion packs (2-cell Kokam 3.2AH) lasted over 200 cycles and was still working. This same system will be released in the R/C airplane world first as 2-cell "Balance Pro" packs and then this summer as 2s to 6s Skyvolt packs using 1p to 3p Kokam 2AH and 3.2AH cells. The real key to performance here is Lithium technology, unique Kokam cell plate designs, balancing cells on charge, monitoring cells for discharge minimum voltage, and only charging to 90% instead of 100% voltage.
To answer your question, you can always run a pack under the rated continuous current level without issue. For replacing your 14-cell NiMH pack, you would want a 4-cell Kokam 3.2AH pack (or two 2-cell packs in series). This would drop your plane RTF weight over 1/2 pound so you will also see improved power level and duration.
< Message edited by Greg Covey -- 5/20/2005 2:12:52 PM >
_____________________________
Visit my Web Hangar at www.gregcovey.com/rc.htm
|
Printable Version
All Forums >> Electric Aircraft Universe >> Electric Training >> RE: Multiplex Magister RTF 
RE: Multiplex Magister RTF - 
. 
