<roh>
simply because they deal much better with physical safety and low temperatures. classic li-ion/li-po may be a notch better in energy density, but they are both exotherm and cannot handle winter
<whitequark>
already suggested lifepo to him
<whitequark>
too expensive apparently
<roh>
well.. i use that stuff in packsizes up to 423 or 530Wh for some time now.. and can say for sure that as long as you want to use mobile/outdoor for more than a few minutes, one needs proper batteries anyhow. what sense does cheaping out 10% bring when the pack dies after a year
<whitequark>
interesting
<whitequark>
btw roh, i had an idea recently
<whitequark>
as you well know li-ion/poly is prohibited on planes in certain configurations
<whitequark>
i haven't found anything that prevents me from bringing a 200Wh lifepo4 external battery on an intl flight
<arossdotme>
oh drat didnt think about winter
<arossdotme>
err lots of bubble rap to keep it warm?
<arossdotme>
roh, i hear you and i put bat life time and quality into my considerations.
<arossdotme>
so for example. i only want usb power banks with those really high mah Panasonic cells
<arossdotme>
posted a link for a bank that used them yesterday
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<arossdotme>
i was planning on making a big pack my self but then this discount huge rc pack came along from hobbyking and well, my thinking was ill try and see. i dont expect the mah to be what it was, but it sounds like that they dont lose there mah that quickily according to DocScrutinizer05. so goodie. i hope that if i look after it, like only discharging it to 3.5v and not storging it fully charged ill make it last its 500 cycles
<arossdotme>
the problem with lifepo cells i think was finding somewhere to buy them from
<DocScrutinizer05>
LiFePo has a vastly different cell voltage
<arossdotme>
whitequark, i dont normally search ebay, ill have a look
<DocScrutinizer05>
only 3.2 to 3.3V
<arossdotme>
DocScrutinizer05, yep. not so high... oh ok so not much diff
<DocScrutinizer05>
o.O ???
<DocScrutinizer05>
you can't use any LiIon standard stuff for LiFePo. Neither chargers nor balancers nor any other stuff
<arossdotme>
i was typeing a reply... then you posted numbers so i added a extra sentence to indicate that i thought the voltage diff was bigger that it was. thx
<DocScrutinizer05>
it's a whole 1 volt diff
<arossdotme>
doh
<DocScrutinizer05>
try to charge a LiFePo to 4.2V and watch it go dead
<arossdotme>
oh lifepo 3.2 to 3.3v cus li-ion is 4.2, 3.7 norm. arrgh im confusing my self. 3.this 3.that 333333333 o.0 ;)
<arossdotme>
sorry thx
<DocScrutinizer05>
well, the end charge voltage is around 3.6 to 3.65V, so it's 'only' a 0.6V difference to LiCoO2 (standard LiIon)
<DocScrutinizer05>
invariably you need a special LiFePO4 charger and balancer/protector circuit
<whitequark>
chargers often support multiple standards
<whitequark>
i have a charger thats liion/nimh/lifepo4
<whitequark>
for 18650s
<DocScrutinizer05>
well, depends
<DocScrutinizer05>
you need one that explicitly does
<DocScrutinizer05>
charfing a LiFePO4 in a LiCoO2 charger is a sure bet for disaster
<DocScrutinizer05>
LiFePO4 is less likely to catch fire and explode, but it's not impossible
<enyc>
I didnot' know 18650's came in form of NiMhs -- woul think that would be worng voltage for whats expected in that size
<DocScrutinizer05>
a smart charger could distinguish cell chemistry by (delta-)V/t observing
<DocScrutinizer05>
a LiFePO4 will stay at ~3.3V for quite a while, then suddenly sharp rise to 3.6V
<DocScrutinizer05>
a LiCoO2 should stay at 3.6 to 3.9V and then less sharp rise to 4.2V
<arossdotme>
is LiCoO2 the old li-ion that had a norm of 3.6V?
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<qi-bot>
[commit] Stefan Schmidt: atusb-eui64: add utility to read/write and EUI64 from/to the device EEPROM (master) http://qi-hw.com/p/ben-wpan/55de8c6
<qi-bot>
[commit] Stefan Schmidt: atusb/fw: add EUI64 read and write fw interface to permanently set an EUI64 (master) http://qi-hw.com/p/ben-wpan/583a7b7
<qi-bot>
[commit] Stefan Schmidt: atusb/fw: Bump version to 0.3 after adding EUI64 read/write handling (master) http://qi-hw.com/p/ben-wpan/fde38d5