question about new batteries

Loading thread data ...
Very high capacitry to weight and pretty hiogh power to weight ratio is the advantage. Disadvantages are teh need for a different charge regime, and the ability of te cells to catch fire and pop - sometimes even explosively - if overcharged or damaged in a crash. The cases are deliberately less tough than Nicads to stop them being shrapnel grenades if they over heat, and that makes them less crashproof.
Lots of info on the E-zoen -
formatting link
Suggest you look there and abosrb all the data before dedciding.
For us leccy flyers the pleasure is well worth the pain. I am not sure the advnantages for glo flyers are sufficient to make it worth while tho.
Reply to
The Natural Philosopher
Nowhere. Not $40 for a 40 sized plane. More like $400.
Hmm. TYhats an ambigous statement..did you mean 'current capacity in mA/h or CURRENT capacity, in amps?'
:-)
Actually, capacity martches nicads, but peak currents don't. You can dischareg a sub C at 100A plus and get 4 15 minuite burns out of it, but a Lpio will explode ...so you nbeed them in paralellel.
The real reaosn for low capacity is that sub C Nicads were developed for power tools, LIPOs were developed for mobile phones and laptpos - which donb';t take that sort of power.
Yes. If someone can post the all up weight of a typical wet powerplant including fuel, tank, muffler and servo, and engine mount, it would be interesting to compare the two. The lower vibration of elecetrics means that lighter structires are possible as well.
As someone else has pointed out, another great gain from LIPO technology, is that even fairly inefficient brushed motors can gain huge increases in power to weight and duration. This makes multi-engined electric scale models a LOT easier - and cheaper - to design, and fly.
Reply to
The Natural Philosopher
Actually LI batteries are a cinch to charge right. Dump a voltage and current limited supply on them. Limit the current to the one hour charge rate and the voltage to (IIRC) 4.2v per cell, and when the current drops to bugger all, they are charged. Or near enough for most puroposes. You CAN get a bit smarter than that - using pulses to shorten charge time a bit, but that will get you 90% there very easily.
The big danger is overheating by applying too much of volts or current. They burn nicely, and may semi-explode (pop?) or turn into miniature rockets. They will also do this if shorted. Protection circuits introdce too much power loss for electric flyers, so we run em 'dangerous'
Precautions of a more strict nature than with Nicads are indicated, however for every LIPO fire there have been dozens of Nicad fires. Again, there are more Nicads out there...
Reply to
The Natural Philosopher
One pother hint from the E-zone. Dump suspect and rapidly heating packs in SALT water. Its sup[posed to cool, discharge safely, and generally ruin the ability of the pack to be dangerous fairly quickly.
I wopuld disagree on the 'don't charge them in teh model' thoo.
That's tantamount to saying 'never put methanol fuel in a model as the model may catch fire'
Its true, but an acceptable risk IMHO.
Red Scholefield wrote:
Reply to
The Natural Philosopher

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.