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'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.
Sort of off topic, but I can't think of a better forum to ask this question.
I've been using the more recent TP4056 based circuit boardswith power out terminals as a smallUPS for my WiFi-router.
The problem is that it will not give away any power on the load terminalswhen...
Thought it could be nice todocument my progress on the forum.
Starting of with my 7s20p witha maximumcapacity ofabout 1kWh.
Best cells (~2500mAh)in the top left pack, crappy cells (~1500mAh)in the bottom right pack.
Waiting for a couple of meters withshrink tube from Chinato isolate...
I'd love some general feedback on my project.
I'm working on a 7s20p. Arather small solution I hope to be able toscale up two or three times over as I get my hands on more cells, i.e. upgrade to7s40p and then to7s60p.I wish to do this without having to replace any existing wires etc...
Just saw that Dacian managed to hit the $40k goal with just a few days left. Very happy for him but even more happy for me and reallylooking forward to my SBMS120.
I'm a city dweller that for a long time have planned anoff grid cottage to spend a week innow and then. Started picking up and old laptop cells at the recycling center a few months ago when I had a lot of business going there to get rid of the excess stuff we've gathered though...