What do you guys think of this: callpod fueltank?

http://www.callpod.com/products/fueltank
http://reviews.cnet.com/power-device...-33481171.html

The idea looks solid though depending on how the adapters exactly work, they might be gouging you for money with them. Also on long trips there's the problem that you need AC to charge the battery pack in this one, standard batteries are easy to come by (just about) anywhere.

The specs say nothing of battery voltage, if it's single-cell LiPo (3.7V) then the 4300mAh is actually 35% less due to the need to boost the voltage to 5V for charging (minus any inefficiencies and the fact that you cannot deep-discharge LiPos and expect them to survive the experience)

Did this refer to the battery voltage?
Output Charge Power 5.4V / 6.4V @ 500mA per port

Full list:
Electrical
Battery Capacity 4300 mA/hr
Battery Source Lithium Ion
Estimated Charging Time 2.5 Hours
Input AC Power 110-240V AC, 50-60 Hz
Output Charge Power 5.4V / 6.4V @ 500mA per port
Power Source Refuel via AC power

Environment
Humidity 5% to 90% Non-Condensing
Operating Temperature -10°C to 50°C
Storage Temperature -10°C to 50°C

Physical
Dimensions 3.4"W x 4.9"L x 0.722"H
Weight 7.3oz (207.0 g)

User Interface
LED Indicators Charge capacity indicators
Number of devices supported 2

That's the ouput eg. charge voltage, but the question is whether the battery pack(s) have 1 or more cells in them, eg. what's the internal voltage. I would say it's likely 2 cells in series (which would conviniently give the 6.4V without boosting as long as the batteries are full, of course as they lose charge the voltage drops as well).

Current is not a problem for lithium batteries: my heli batteries are rated (as in can supply without damage to the battery) for 30 x capasity for burst and 25 x capasity for continous current, with 2.2Ah capasity this comes to 55A continuous current (at 11.1V nominal voltage thats 610W of power! [for about 2 minutes]) and 65A burst... If you short-circuit the battery expect very violent results...

Aside the main point: it just occured to me that the TEC103 can charge single cell lithium batteries too, so the frankencharger could be rigged to work with single 18650 as well (something I'll be sure to try once I get the torch agent770 suggested)

Args, it took 6 days for DealExtreme to even get my order shipped, depending on luck it might or might not arrive before I leave...

Anothar nice review from anythingbutipod.

I still prefer the external battery mentioned before. Just receive my new N810, and charge it without complaining (and the N810 is far more picky than the 770, for exemple, ny N810 refuse to charge with a genuine nokia phone charger, while the 770 did)
The callpod get double capacity, but is more than 2 times bigger, uses proprietary connector, and is nearlly 3 times more expensive.