mm-a-bat.htm; updated: 16 June 2002
MicroMag Application: Batteries
NEW SUPERIOR LITHIUM POLYMER BATTERIES NOW AVAILABLE !!!!!!!!
Just about to arrive and deliver are the new Lithium Polymer batteries.
145 mAh, 3.7 Volts, 3.5 Grams ! ! ! !, and up to 1 Amp continuous. What do you want more?
performance is amazing, the Tri-X triplane shown in the picture
gallery did barely fly on 3 Sanyo 50 mAh because the weight was
rather high. On 3 GP 80 mAh it did only 2 minutes because the
cells cannot realy take the current draw of the KP-00 motor.
With the new LiPolymer cell the plane is only 18 grams and flies over 12 minutes. doing loops and barrelrolls. These cells did really transform the model.
only (slight) drawback is that they need 2 to 3 hours recharge
and a dedicated (but not expensive) charger.
See Confectioning the Li-Polymer cells for information on soldering to the new Li-Polymer cells
The 50 mAh Sanyo NiCd cells of 3.6 gram each are still good batteries when you want cheap quick rechargable batteries that can deliver a substantial current. Three are required for powering a motor model, these weigh 11 grams with connector. You can draw more than an Amp from it (for a very short motor run) they are reliable and you can safely charge them at 300 mA. (some even use 500 mA or more).
The rather new 70 mAh Nickel Metal Hydride cells from GP looked promising, but are not really suitable for E-power.
The newer 80 mAh
cells are better and lighter. Each is 2.2 grams, so 3 cells and a
connector only weigh 7.0 grams!!!
The capacity is good, don't expect as much current as you can draw from the 50 mAh Sanyo NiCd's.
A constant discharge current of about 300 mA is the absolute limit. But then you can fly several minutes. When you keep the current down to below 200 mA you can expect to fly 20 minutes or more. This needs an efficient plane and/or motor.
Charging is done at 120 mA when the cells are new and 180 mA when broken in.
The new LiPolymer batteries makes these cells redundant. You get half the weight at double capacity and three times the current capability with the new LiPo's.
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