I have this collection of 40Samsung INR18650-29E thatbehave strange according to me.
After charging them to 4.2V they drop to 4.15V in a matter of minutes. After a few hours they drop top 4.12V and seem to stay stable there "forever" (only had them for so many weeks). If I recharge a 4.12V cell...
I'm sick of the crappy springy cell holders you find everywhere. Want to get a bunch of the kind usually found on cell testing devices. What are they called or where can I get them?
I.e. not these:
But the kind found on this:
If I getbatteryuniversity.com right, then keeping my packs between 3.2V and 3.9Vgives me about ten percentage point less capacitycompared to3.2V and 4.0Vbut two to four times the longevity of life. Sounds like apretty good deal to me.
Given I have enough cells to handle the capacity loss and...
I do 11m dxpeditions during the summer. Enjoy climbing rocky knolls in the Swedish west coast archipelagos, bringing a small QRP rig and a simple dipole. Almost always great conditions to somewhere in the Brittish isles, but have over the years been getting QSOs with pretty much everything but...
I've posted a couple of images in requested thread.
Btw, the capacity I've measured on brand new cells when charging to 4.2v, waiting 24 hours and then discharging at 500mA to 3v is 3326mAh, 3184mAh, 3180mAh, 3176mAh and 3165mAh.
I'm looking for a charger circuit with variable over charge cutoff voltage, alternatively one set to 3.8v cutoff. Anyone aware of such a thing? I'll be charging very small cells with this, say 500mAh or so, to be used as UPS for up to an hour or sowith small WiFi-routers.
Freelance software developer.
Do a lot of my own projects too, but they're generally economic disasters compared to working for the man. :D
Open source, open data. Machine learning and information retrieval. Geography. I suppose you could put me in the "big data" box, if that helps, although...