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

That is awesome!

This sounds like a SkyRC MC3000, without the bluetooth and PC interface. Which is great, because I have no need for the buggy bluetooth stuff or awkward PC connectivity.

So, the obvious solution is to ask SkyRC to see if they will produce it for $39 (or $49 with the USB stuff, which I don’t need). Has BlueSword asked SkyRC, and if so, have they responded?

If they come back with nothing but laughter, maybe a Plan B is needed. Or, increase the price.

I can’t speak for anyone else, but for me, the difference boils down to two things — usage and availability.

Usage:

  • A flashlight is something I carry around constantly and use dozens of times per day. So I want it to be good because I spend a lot of time using it.
  • A charger is something I only spend a few seconds with once every few weeks. As long as it refills my batteries safely, I don’t really care about the details. I plug it in, put a cell inside, then go do something else. A few hours later I take the cell out and unplug the charger. If I’m curious, I might also glance at it once in a while to check progress, so a display is nice to have.

Availability:

  • I make flashlights because I wanted something and it didn’t exist. The desired features simply weren’t available.
  • With chargers, what I want is widely available and there’s a lot of room to grow if desired, without having to do anything custom.

I mean, with flashlights, first I tried not making it… but that didn’t work. So I fell back to Plan B. But with chargers, when I tried Plan A (not making it), the result was agreeable. So no need for Plan B; the market already met and exceeded my battery-charging needs.

I’ve been googling around for this and haven’t been able to find it. Link? It sounds very interesting.

@Parametrek, I will not link it yet. It’s been in translation from French to English for a while, and I’m debating whether I should release it or not.

It was more of a side-project when I was doing my main project at school(motor oil recovery methods with various solvents, distillation, electrolytic restoration, etc), so maybe I should release it one day.

One thing is for sure: I’m going to release it when I want it. :wink:

To quote myself when I wasn’t as good in science English:

My current hypothesis is that the the lithium concentration inside of the LiCo2 anode is higher than usual, and leads to a phenomenon called passivation layering, along with the lower purity of the cobalt compound, caused the problems we encountered in these cells. It’s still not certain, but I could come to a conclusion in a few weeks.

Basically, this usually happens in lithium primaries due to their very high concentration of elemental lithium, forming a passvation layer as the battery isn’t used. This isn’t really bad for them, as they aren’t rechargeable, meaning it isn’t a problem. In fact, it lowers their self discharge rate significantly.

I came to that statement, because I noticed that with my Sanyo cells from that time, their self discharge rate is very low, even for a lithium ion battery. Even my best new cells didn’t have that low of a self discharge rate. So, I did some more research, and apparently, that behaviour is quite bad for lithium ion batteries on the first cycles, as by clearing that passivation layer, the internal resistance is quite high in the beginning, resulting in much more heat than usual if a battery was stored for a while. With the lower purity of the cobalt used, it resulted in an actual lower thermal runaway threshold.

That, along with charging a possibly months old pack along using the computer in a high heat environment, lead to the thermal runaways, and the massive recall.

@WalkIntoTheLight and others, why are you worrying about this project not coming into fruition?

If we only want the basic features we want, it should be fairly easy to have a charger built with these demands in mind.

It’s the more advanced features like advanced discharged capabilities using MOSFETs, USB data connectivity, microSD card compatibility, deeper slots for very large cells, etc.

It sounds like a great idea, so I’d like to see it come to fruition. I think the best way to achieve that is to make the goals reasonable. I don’t think you’re going to get an “improved SkyRC MC3000” for less than half the price of the current model. Though, I’m happy to be proved wrong. But if it takes 3 years and 10,000 posts to be proved wrong, I’m not sure that’s good either.

Anyway, I don’t mean to be down on this project of yours. I really do wish you the best of luck. I think you should have an idea in a month or two whether it’s possible or not. If there’s no progress by then, I hope you’re still interested in a scaled-down version, like a Nitecore SC4 with settable termination voltage.

Or, continue with the one with all the bells and whistles, and maybe someday it will come to fruition. As someone else said, it’s not costing us any money.

Should be good if it actually happens , as long as lumentop don’t have anything to do with it :laughing:

Thanks, that’s a very interesting site. It seems there is a forum for everything. What a world.

Heh, that’s fair enough. But this project is aimed at those who are not satisfied, for one reason or another, with what is available. And wouldn’t you agree that IF BLF is going to develop a charger (or anything else), it ought to be better, different, and/or cheaper than what is already available?

Value is an important consideration at BLF, which is great. And I think a case could be made that an advanced charger will pay for itself over time, especially if you factor in something for peace of mind. For example, with a LiIon 18650, raising the termination current (in the constant voltage phase) from 0.1A to 0.4A (something you can’t do on any budget charger I am aware of) will reduce the stored energy in the cell by about 10%, but double the longevity of the cell in terms of charge cycles (source: HKJ, and Battery University). With NiMH cells, changing the DV peak (or plateau) so that charging termination is prompt and reliable can prevent chronic overcharging. Restoring a depleted LiIon battery safely to full capacity rescues a cell otherwise bound for the landfill. Testing the actual capacity of batteries can give you peace of mind, as well as help you avoid counterfeit cells.

Batteries are pretty cheap, but there is an environmental cost, too. My point is that there is some hidden value in the price of an advanced analysing charger. And anyone who can learn to use Anduril can learn to use one. Save money. Save the planet. Have more fun. I know I’m mostly preaching to the converted here, but let’s get behind this project!

This is an important point that deserves reflection. When many of us first started we had a 1-2 cells total. Now with these amazing high power lights, we need 4-8 cells per light.

2-3 years ago I never thought I would need more than 5 cells. Now I have 52 just in one bike battery pack.
The longer we can keep them in good shape and extend their life, the better for the environment. The mining of the raw materials does a lot of damage and is not usually a consideration (ahem tesla buyers :person_facepalming: ).

Not to sound like a complete hippy, but we should at least try to be responsible and take good care of our cells so we are not replacing them every year.

INPUT power —- handle variations from solar panel shading, clouds/shadows, etc.

Make this usable off the grid, after the earthquake/tsunami/meltdown etcetera.

That means not resetting or losing track of cell voltage and then overcharging a cell after a power flicker.

Great stuff!!
Hope something comes of this

Suggestions

  1. Dual voltage or provide two models to choose from (110V for US & Canada and a 230/240V for AUS, UK, Asia, Africa etc)

2. I’d like a white charger with a simple black and white LCD will do if we’re picking colours

3. Maybe a naming competition later down the track

Hi Hank & Ragsy. I think Blue has you covered already on spec # 7. 12V-20V compatibility and I think he means input voltage.
That will work well with a 12V solar cell input. Ac to dc wall adapter can have an input range from 120-220VAC for worldwide compatibility.

Yep. Same here.

Agreed.

That’s why I generally charge cells when they get down to ~3.3V instead of waiting until ~2.8V. Also why I usually only charge them up to 4.0V or maybe 4.1V, instead of going all the way to 4.2V. And I don’t quick-charge them. And if a cell is going to be sitting unused (or only slightly used) for a while, I usually drain it to about half full first. These things all extend the cell’s life span in years.

A charger doesn’t really help much with this though… except for chargers built into lights. Those make it a lot more convenient to keep the battery at middle voltages. It’s particularly helpful for multi-cell lights, since married sets are otherwise pretty inconvenient to do partial charges on. So I’m hyped about the charger built into the BLF Lantern.

The kind of charger I’d really like to see BLF make is a circuit which could be integrated into existing lights, to give them the ability to do wireless inductive charging. It should theoretically be possible as long as the host material isn’t ferrous. They’ve been doing this in electric toothbrushes for 25 years… so it’s probably feasible in a flashlight.

Charging to 4.0v or 4.1v certainly helps with numbers of cycles. It might give you 1000 cycles, instead of 500. But at some point, you have to ask, “Am I really going to use this cell 1000 times?” Diminishing returns at some point. I still do it, about half the time, especially if it’s in a light that I don’t use much. Though, that’s probably exactly the wrong way around from what I should be doing.

I’m not so sure about prolonging cell life by keeping them around 50% charged. Yes, you may as well do it if you don’t plan to use the cell for a few months. But, I think it’s a bit of a myth that storing cells at 100% is extremely bad for them. Maybe true in the past, but modern cells seem to hold up well.

I have old laptop cells that are over 10 years old. Samsung 22H cells, and they were always kept fully charged. Original capacity 2200mAh. They still test at an average around 1900mAh. Not great IR, but still good enough for a few amps. I think that breaks the myth of 20% reduction in capacity every year.

The SkyRC MC300 will do all the things you mentioned, fully automated and unattended. If I want to charge a cell to 4.1V at 0.5C rate, I can push one button, come back hours later, and voila. Ditto for storage charge, balancing cells, and so much more. I think people are much more apt to take better care of their batteries if it is easy.

So, I’m almost finished on the feature list.

If I can, I’d like to make the full featured charger available either at the end of the year, or next year.

About input power, can we adapt to Quickcharge or power delivery type C port?, they are popular, and maximum of power delivery is 90W, more than enough for us. And using Type C port we can reverse charge our phones or tablets.

Anker atom 30w pd charger is much smaller than 12V 24W adapter.