kyak changed the topic of #qi-hardware to: Copyleft hardware - http://qi-hardware.com | hardware hackers join here to discuss Ben NanoNote, atben/atusb 802.15.4 wireless, anelok and other community driven hw projects | public logging at http://en.qi-hardware.com/irclogs and http://irclog.whitequark.org/qi-hardware
solrize has joined #qi-hardware
<roh> you all like good hacks, do you? ;) just stumbled onto this: http://blog.vinu.co.in/2016/03/stm32f407-discovery-board-as-100mhz-fm.html
fengling has joined #qi-hardware
fengling has quit [Ping timeout: 240 seconds]
fengling has joined #qi-hardware
kyak has quit [Ping timeout: 244 seconds]
DocScrutinizer05 has quit [Disconnected by services]
DocScrutinizer05 has joined #qi-hardware
<wpwrak> roh: that 22k resistor is disappointing. should have used chip-internal tuning caps ;-) (dunno if the stm32f407 has them, but many MCUs do)
rjeffries has quit [Ping timeout: 250 seconds]
sandeepkr__ has joined #qi-hardware
archang has quit [Ping timeout: 260 seconds]
sb0 has quit [Quit: Leaving]
sandeepkr__ has quit [Read error: No route to host]
sb0 has joined #qi-hardware
FDCX has quit [Remote host closed the connection]
GeorgeHahn has quit [Read error: Connection reset by peer]
solrize has quit [Ping timeout: 268 seconds]
<arossdotme> usb power banks btw. there older version (no quickcharge) has panasonic cells too i think. there selling them for £15! cheep, prev model stock http://www.amazon.co.uk/gp/product/B019GJLER8/ref=ask_ql_qh_dp_hza
<arossdotme> guess the cells have aged
<arossdotme> that or there not valued so much now they have a new product version to sell instead?
archang has joined #qi-hardware
solrize has joined #qi-hardware
solrize has quit [Ping timeout: 248 seconds]
solrize has joined #qi-hardware
kyak has joined #qi-hardware
FDCX has joined #qi-hardware
pcercuei has joined #qi-hardware
pcercuei has quit [Quit: brb]
pcercuei has joined #qi-hardware
<DocScrutinizer05> the latter. LiIon don't age that much when stored vharged to >50%
<DocScrutinizer05> if however they - for whatever reason - got stored a few weeks in depleted state, they are dead
* DocScrutinizer05 should trickecharge all his GTA02 batteries again
<DocScrutinizer05> about time, last time I did that is more than 2 years ago
<DocScrutinizer05> ((good hack)) well yes, it's a not bad but the last kick is somehow missing
<roh> hm. i got thinkpad batteries with sanyo and panasonic cells.... i must say... panasonic is _so much better_
<roh> keeps >80% capacity even over years.. sanyo wears down fast, if used or not
jow_laptop has quit [Ping timeout: 260 seconds]
jow_laptop has joined #qi-hardware
<arossdotme> thanks again!
<arossdotme> mmh panasonic cells that good... ill have to see how long this discounted £31 s4 20Ah rc batt lasts heh. the experment as arrive and is in lap :)
<arossdotme> oh its a 10c one. one of the lowest discharge, aimed for more Ah instead.
<arossdotme> awww 1.5KG for battery! :D
<arossdotme> for=of
<arossdotme> if i charge it now i start its life cycle and from them on it needs to be used or it will decay? or does it make no differance when i charge it for the first time? what matters is that i discharge/charge it to something like 50% for when im not using it, right?
<DocScrutinizer05> right
<arossdotme> good :)
archang has quit [Ping timeout: 240 seconds]
xiangfu has quit [Ping timeout: 260 seconds]
xiangfu has joined #qi-hardware
pcercuei has quit [Quit: leaving]
<arossdotme> hmm it came charged to 3.9v per cell :/ hmm thats 90%(i think i did my maths right) charged. no where near being 50%
<arossdotme> hmm
<arossdotme> is it so its ready to use when it comes in the post?
<DocScrutinizer05> not completely, it's supposed to get charged for a 16h - arguable if that's backed by facts or cargo cult from NiMH/NiCd
<DocScrutinizer05> I guess once charging in a CC/CV charger until I_trickle signals end of charge is enough
<DocScrutinizer05> of course you also could use a decent lab PSU, adjust it to 0.1C current limit and 4.20V*number of series cells, and connect the battery pack for 16h
<DocScrutinizer05> or, if your charger actualy does same, keep it in charger for 16h
<DocScrutinizer05> if your charger has no trickle charge function, you also can restart charging after 4h, 8h and 12h (unless your charger is of the completely braindead kind that first DIScharges battery before charging it - strongly deprecated for LiIon)
<DocScrutinizer05> ((3.9V) seems fine. The "50%" is a ballpark number, other suggestions are "75%" and for air freight the cells will not be allowed to have more than 30%. Actually I think it's about voltage rather than charge percentage level
<DocScrutinizer05> at least for aging during storage. There's also a recommendation to store the cells at between 0° and 10°C. Some recommend freezer, while others (incl me) strongly discourage to do that
<DocScrutinizer05> fact is: LiIon cells age faster with keeping them floating at max voltage (4.2V), and they age *much* faster at elevated temperatures of >25°C
<DocScrutinizer05> and they age like mad when overcharging them
<DocScrutinizer05> like >4.2V
<DocScrutinizer05> this even applies to cells that are specified to 4.3V or 4.4V
<DocScrutinizer05> I.E. those "overvolted" cells specify for a maybe 5% or 10% more capacity (from the 0.1 to 0.2V higher voltage) but they also state a factro 10 lower cycle count until EOL
<DocScrutinizer05> factor
<arossdotme> arr i was wondering about those higher voltage cells. thanks
pcercuei has joined #qi-hardware
<arossdotme> wondering = there pros and cons
<arossdotme> my chargered is designed for rc lithium batts
<arossdotme> it has a storage or discharge mode
pcercuei has quit [Quit: brb]
bzb has joined #qi-hardware
bzb has quit [Remote host closed the connection]
pcercuei has joined #qi-hardware
pcercuei has quit [Client Quit]
pcercuei has joined #qi-hardware
pcercuei has quit [Quit: leaving]
GeorgeHahn has joined #qi-hardware
rjeffries has joined #qi-hardware
dcht00 has joined #qi-hardware
solrize has quit [Ping timeout: 240 seconds]
solrize has joined #qi-hardware
jwhitmore has joined #qi-hardware
rjeffries has quit [Ping timeout: 240 seconds]
FDCX has quit [Remote host closed the connection]
FDCX has joined #qi-hardware
FDCX has quit [Remote host closed the connection]
FDCX has joined #qi-hardware
FDCX has quit [Remote host closed the connection]
FDCX has joined #qi-hardware