| > "It is recommended that you completely discharge the battery
| > during the initial test flight before following the charging
| > guidlines outlined below."
| That MUST have referred to NiCD or NiMH batteries - definitely not for
| LiPo packs.
Of course, that's not even a good procedure for NiCd or NiMH
batteries. And the original poster didn't actually tell us what the
charging guidelines are ...
| Ok, LiPo Batteries... :) To prevent deep discharging LiPo packs there
| are so-called Battery Eliminator Circuits (BEC), which provide an
| automatic cutoff.
That's not actually what the BEC does. The BEC powers your RX and
servos, and generally has no cutoff whatsoever. (Because you'd
generally rather ruin your battery than lose control of your plane
| Some of them provide advance warning by artificially lowering power
| output and/or beeping so that your heli doesn't drop out of the sky
| all of a sudden - highly recommended.
That's the function of the ESC itself. Your ESC may have a BEC built
in (many do) but it's not actually the BEC that does this.
| Others like the ones in my planes just cut the power to the engine
| as soon as the battery drops below a certain voltage. Okay for
| e-planes where you can glide down, but not for helis.
Right ... cutoffs are not suggested for helicopters. A beeper or a
LED to warn you when you're losing power isn't a bad idea, but
suddenly losing power when flying low and inverted is.
Cutoffs aren't actually that important. As a rule of thumb, when
you've dropped from 4.2 volts/cell to 3.0 volts/cell, you've lost half
your power, which should be very noticable on any plane that's not
flown far away (like a powered glider.) As long as you pay attention
to how your plane/helicopter is flying, you'll generally know when
it's time to stop and charge. An automatic cutoff is a nice safety
measure, but it's not essential.
| Balancing chargers are often more expensive, but better for LiPo battery
They don't have to be expensive. For example, this one --
is only $12.
| Remember the recent laptop fires? That's approximately what happens
| if you're not careful with that type of battery. These fires burn
| very hot and cannot be extinguished with normal fire extinguishers.
Yes they can. This isn't greek fire or anything like that. (And if
you feel that I'm wrong about this, please, provide some references
for this claim.)
Yes, LiPos can spontaneously catch fire when abused, which makes them
dangerous, but the fires they create aren't more dangerous than other
fires of similar sizes. (Though you may have a bunch more LiPo cells
near by, waiting to catch fire on their own -- but that's not any
different than many other things that can burn.)