The evolution of battery technology never stops to amaze me. We always seem to benefit greatly in the electric flight world from lighter weights, longer duration, and increased current delivery capability.

Shown here are three different battery technologies in a common shape made popular by Zagi wings and similar models.

From top to bottom, we have:
[ul][*] Thunderpower [link=http://www.hobby-lobby.com/thunderpower.htm]TP420032[/link] 3s2p, 4200mAh, 11.1v Lithium pack (8.9oz)[*] Sanyo ([link=http://www.flydma.com/batteries/batteries.asp?path1=batteries]DMA[/link]) 8-cell, 1700mAh, 4/5AUP, NiMH pack (10.2oz)[*] Sanyo 8-cell, 800mAh AR, NiCd pack (9.6oz)
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All packs can deliver 20-30amps (or more), and, weigh similar amounts , but the energy density winner is clearly the ThunderPower Lithium technology. Additionally, the TP Lithium pack has the equivalent voltage of a 10-cell NiCd pack which allows for better peak burst performance!

If we based our flight time on a 20amp draw, we can see the duration improvement from the various packs below:

[ul][*] 800AR NiCd pack = 2.4 minutes[*] 1700 NiMH pack = 5.1 minutes[*] 4200 TP Lithium pack = 12.6 minutes
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