#qi-hardware IRC log for Thursday, 2016-03-17

arossdotmethis is an interested BMS http://www.aliexpress.com/item/FMA-Balance-BMS-PCM-for-4S-14-8V-Li-ion-Li-Po-Battery-C-20A-Temp/32630267805.html?ws_ab_test=searchweb201556_9,searchweb201602_2_10034_507_10032_10020_10001_10002_10017_10010_10005_2020019_10011_10006_10003_10021_10004_10022_10009_10008_10018_10019,searchweb201603_8&btsid=b219447d-4b95-4dbd-8162-3fe68263931317:04
arossdotmeits got an thermistor17:05
arossdotmeor this one, a one i prev linked to, looks like it also has connections for a thermistor but doesnt include one: http://www.aliexpress.com/item/4S-14-8V-16-8V-Lithium-Battery-Protection-Board-20A-BMS-PCM-for-18650-Lithium-Batteries/32611828360.html?ws_ab_test=searchweb201556_9,searchweb201602_2_505_506_503_504_10034_10020_502_10001_10002_10017_10010_10005_10006_10011_10003_10021_10004_10022_10009_10008_10018_10019,searchweb201603_8&bt17:07
arossdotmesid=eab159c2-6860-492f-81c2-340fa406b7ff17:07
rohi'd recommend using lifepo btw...17:37
rohsimply 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 winter17:42
whitequarkalready suggested lifepo to him17:53
whitequarktoo expensive apparently17:53
rohwell.. 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 year17:58
whitequarkinteresting17:59
whitequarkbtw roh, i had an idea recently17:59
whitequarkas you well know li-ion/poly is prohibited on planes in certain configurations17:59
whitequarki haven't found anything that prevents me from bringing a 200Wh lifepo4 external battery on an intl flight17:59
arossdotmeoh drat didnt think about winter18:07
arossdotmeerr lots of bubble rap to keep it warm?18:08
arossdotmeroh, i hear you and i put bat life time and quality into my considerations. 18:09
arossdotmeso for example. i only want usb power banks with those really high mah Panasonic cells18:10
arossdotmeposted a link for a bank that used them yesterday18:10
arossdotmei 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 cycles18:14
arossdotmethe problem with lifepo cells i think was finding somewhere to buy them from18:15
arossdotmegot any links?18:15
arossdotmeroh, ^18:16
whitequarkebay.com18:18
arossdotmebtw this monitors are brill! wise there was a version with a huge display and a much bigger time remaining countdown? http://www.aliexpress.com/item/80V-50A-Coulomb-gauge-electrical-parameters-lithium-battery-LCD-display-instrument-TF01N/32232092752.html18:18
DocScrutinizer05LiFePo has a vastly different cell voltage18:19
arossdotmewhitequark, i dont normally search ebay, ill have a look18:19
DocScrutinizer05only 3.2 to 3.3V18:19
arossdotmeDocScrutinizer05, yep. not so high... oh ok so not much diff18:19
DocScrutinizer05o.O ???18:19
DocScrutinizer05you can't use any LiIon standard stuff for LiFePo. Neither chargers nor balancers nor any other stuff18:20
arossdotmei 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. thx18:20
DocScrutinizer05it's a whole 1 volt diff18:21
arossdotmedoh18:21
DocScrutinizer05try to charge a LiFePo to 4.2V and watch it go dead18:21
arossdotmeoh 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  ;)18:23
arossdotmesorry thx18:24
DocScrutinizer05well, the end charge voltage is around 3.6 to 3.65V, so it's 'only' a 0.6V difference to LiCoO2 (standard LiIon)18:26
DocScrutinizer05invariably you need a special LiFePO4 charger and balancer/protector circuit18:30
whitequarkchargers often support multiple standards18:30
whitequarki have a charger thats liion/nimh/lifepo418:30
whitequarkfor 18650s18:30
DocScrutinizer05well, depends18:31
DocScrutinizer05you need one that explicitly does18:31
DocScrutinizer05charfing a LiFePO4 in a LiCoO2 charger is a sure bet for disaster18:32
DocScrutinizer05LiFePO4 is less likely to catch fire and explode, but it's not impossible18:33
enycI didnot' know 18650's came in form of NiMhs  -- woul think that would be worng voltage for whats expected in that size 18:34
DocScrutinizer05a smart charger could distinguish cell chemistry by (delta-)V/t observing18:35
DocScrutinizer05a LiFePO4 will stay at ~3.3V for quite a while, then suddenly sharp rise to 3.6V18:36
DocScrutinizer05a LiCoO2 should stay at 3.6 to 3.9V and then less sharp rise to 4.2V18:37
arossdotmeis LiCoO2 the old li-ion that had a norm of 3.6V?18:41
qi-bot[commit] Stefan Schmidt: flashi/spi: Use tabs instead of spaces. (master) http://qi-hw.com/p/ben-wpan/15b15b921:33
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/55de8c621:33
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/583a7b721:33
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/fde38d521:33
--- Fri Mar 18 201600:00

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