The making of the BLF UC4 charger: the start of a new venture, INTEREST LIST, UPDATE 7 (Well, ramping stopped :/ )

That sounds very interesting for sure.

IF this happens, can we raised the discharge rate too?? If so, that would be very appealing.

The funny thing is, I use a Nitecore i8 at home. It's extremely simple, and I often charge my eneloops in it. But it auto-detects to my liking, and while it's a bit big and expensive, it was also a gift. It also charges slowly, but I care more about battery health than charge speed. The only step up that makes sense in my head currently is to the MC3000, because for the fun don't-actually-need-them features, that's the one that ticks the most boxes.

I do have a spare single-cell USB-powered charger, it is actually a SupFire AC-16, but I've only used it once. It actually currently lives at work. I have a cool tiny charger for my 10250s from CRX and my Klarus Mini One Ti charges its own 10180 cell. I can't remember for sure, but I might also have a charger that came with one of my ThorFire lights somewhere...

Not for sure yet.

You need to make sure that if a shadow moves across the solar cell and voltage drops below the minimum spec the charger recovers gracefully and continues to charge —- rather than resetting to starting from scratch again. This has been a problem and caution I’ve seen brought up repeatedly with small chargers when people tried using solar cells with them.

sounds awesome very interested! :+1:

Input voltage range: 10V-22V

DBSAR’s LT1 lantern built-in charger has this issue figured out already. :wink:

@DavidEF, that’s a bit different

But you just gave me an idea on the software side that would be extremely nice.

Why not make an emergency mode in which it turns off charging if the voltage drops between 4,5-10V, trying to consume as little power as possible just to keep itself on and preventing settings from changing?

It should be relatively easy to implement.

Well, what I meant was that the hardware doesn’t have to crash or “reset” when a shadow looms overhead. It can be made to gracefully recover as if nothing happened. I don’t know if it needs software support for that or not. I assume not. But I’m not an EE. :wink:

Only french will understand : drapal !

If the discharge rate for a single cell was limited to 4.2v at 3 amps it shouldn’t take much more than a 30mm x 30mm space to have it inside the unit.
https://www.aliexpress.com/item/32528721413.html?storeId=923042&spm=a2g1y.12024536.productList_2808692.subject_9
In the model above, you would have to have a few more components added to turn the potentiometer into electronically digital controlled. Like this one.

https://www.aliexpress.com/item/32882318330.html?storeId=923042&spm=a2g1y.12024536.productList_2808692.subject_8
.
The icharger 208b is relatively small in size with alot of power handling but the power supply to reach the capabilities of the charger takes almost twice the size of the charger.
Charging 4 li-ions at 3 amps each would need around 70 watts from the power supply. The max charge rate would all depend on how small and efficient you could make the power supply for it’s size.

I think this was going to do 4 cells at once. 4cells*12.6w=50.4w

Yeah.

You’re going to need at least 50W to dissipate the heat generated by the fully-saturated MOSFETs at full load.

50W would be absolutely massive, especially for a CONSTANT CURRENT load inside of a charger

If your referring to ‘discharge’… I hope it is going to do four cells at one time.

If the heatsink setup mentioned above is added, can the discharge rate be raised above the 750 mAh that is planned now.

Would it be possible to get it up to 2000 mAh (2A) x 4 cells??

Is “mAh” the correct terminology for discharge rate?? :person_facepalming:

If your trying to find out the discharge capacity and have it graphed like HKJ does, I don’t see why you need to do more than one cell at a time. To me seeing what one cell can do at 3 amps is more important than what 4 cells can do at .5 amps.
Doing 4 cells at a time would require 4 data logging graphs going at once which I guess is possible but the first link I posted would handle one battery at 3 amps, so for 4, you’ll need 4 of those or one 4 times the size.

The DIY Powerwall community has hundreds of 18650s to load test. They often buy multiple 4-slot dischargers.

And how much power are they discharging and how big is the load discharger.
If its going to be all in one unit a middle ground has to be meet somewhere, if not then bulkier additional devices could be added I guess.

They only need to find matching cells, so I would guess the faster they can discharge a set and move on to the next set, the better.

And yes, this would be a use case for the CPU cooler add-on. Not a core requirement of course.

How about small cells like 10180?? Make it universal for evey battery out there. And make take protected and unprotected batteries with power bank functionality.

Opus and skyrc and maybe xtar is my choice for manufacturers

So I was went over to https://secondlifestorage.com before dropping a link in this thread, and it turns out BlueSwordM is an active member with a matching display pic. So I guess he’s more qualified to explain this use case. lol

Oh and it seems many of them check the capacity of Thousands of cells. :open_mouth: