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

Yeah, that’s not enough.

We need to use graphite electrodes that can reach 2000C.

600-1000C is not enough.

Excellent Idea and I am totally interested.

Agree with your bare minimum requirements. Want to reiterate them and also have a few questions:

1. Adjustable charging current (0,1A-3,0A) in 0,1A steps. - Could this be done using Constant Current (without PWM on low end) from .1-3A? (Upgrade from OPUS)

2. Support for multiple chemistries. - Perfect

3. Temperature monitoring (45C max below 2A, 60C max below 3A). - Temp sensor to monitor cell temp (approximate) or internal board temps?

4. 4 cell channels - Perfect

5. Active cooling if temperature exceeds 45C, and if all channels are active above 2,5A. - Temp at cells or board location? If for cells, maybe active cooling can turn on lower, say 35C? Variable speed fan please, or connector for us to plug our own in.

8. Nickel coated phosphor bronze/brass rails. - Perfect

9. Internal resistance measurement. - Perfect

11. Adjustable max voltage for lithium ion charging: 3,90V-4,20V in 0,1V steps. - Perfect

12. Storage charge mode: 3,6V. - Could this also be adjustable (from say 3.2-3.7V) or would discharge mode have adjustable termination voltages?

15. 100-200-350-500mA-750mA discharging functionality. - Adjustable termination voltages possible? Say 2.X-3.7V?

1. Most chargers use individual buck converters, unlike the OPUS, so it shouldn’t be a problem.
2. Great.

3. Temp sensors right beside the terminals. At max power(charging 4x30Qs at 12A total), the C4-12 doesn’t get too hot. It’s the cells getting hot, so monitoring cell temps is more important than the electronics’ temps.
4. Great.
5. Same thing as number 3.
8. Would be very nice, and would make inaccurate internal resistance measurement a thing of the past, most of the time anyway.
9. Great.
11. Great.
12. Storage charge mode would just charge/discharge the cell down to 3,6V. I would really like a it down to 3,4-3,5V, but 3,6V is a happy medium.
15. Yes, from 2,6V-3,3V. 3,7V is rather high. What would you want to do with it?

Tip o’ the hat to BlueSwordM! May your knowledge in this area and interest in BLF see you through to the end of this customization project.

As to those who will point out the possible/probable length of time for the project to end in product fruition, either help or wait patiently. Input is easy; Output is hard.

For me, the mere vibrant, constant, and constructive discussion in this thread and constancy of BluSwordM’s leadership will put my acquisition of any more “shelf” chargers on hold (perhaps for many months) pending the outcome of a final product.

If it really were to be designed and built, I know the focus will be on big and long cells. But, if the low charge rate is really going to be 100mah… please make sure it will at least fit 10440 cells without spacers.

I for one, think this community could design a charger to put most chargers to shame and would love to see it happen!

Thanks Blue!

3. Totally agree that monitoring the cell temps is most important. Very happy this charger will attempt it.

15. It would be nice to select discharge cutoff from our storage voltage of around ~3.6V all the way down to 2.6V.
Sometimes I know I’ll need a light for only a few hours and I have a mostly charged cell. 3.7V seems to be the sweet spot since it will end up around 3.5-6V after use. Then it’s ready for storage.
If its easy enough to accomplish in software, I guess its good to have a wider selection range but don’t think its a deal breaker.

Very happy to see such a large response to this thread so far. Seems others also feel there is a void in chargers still.
Let us know how we can help make this a reality.

I’d buy one for sure

this could force me to spend more money! why do i read these things :person_facepalming:

And we want it by Christmas.

How about degrading test?, you put battery into it, it will charge/discharge for a number of times in setting, and logging data into micro sd card.

It’s a tedious task if done by hand

You should try ISDT UI. It’s really quite simple. Yet it allows to conveniently do advanced stuff.

Interesting project. Will pay attention on it

Awesome idea :beer:

All I would like to see in a charger would be:

  • 4 x 2A charging
  • Storage charge/discharge

Basically an upgraded Nitecore SC4 (my main charger now)

Some of those bells and whistles suggestions I could most def be without.
I fear it ending up like this

Like Bluetooth/WiFi connectivity, RGB lighting… Calm down X to the Z Xzibit, don’t pimp my charger.

BlueSwordM, you might want to think about moving this thread to the BLF Special Edition Products subforum.

I think it belongs there, and more people will pay attention to it if it's in that awesome subforum.

I would love to have a charger that I can set for max voltage of 4 volts

Yup, Nitecore SC4, and also add

  • Adjustable termination voltage

(3.6v to 4.35v in 0.05v increments, since that would cover storage voltage ranges, and other li-ion chems as well. It already handles 3.6v, 4.2v, and 4.35v, so should be an easy upgrade)

Done!

The complete list of features proposed sounds great, but I’m really concerned it would never get built, or never meet the price target. And, it might be a nightmare to coordinate, like the FW3A 2-year project, with people eventually dropping out of the development team.

I’d be in for this, no ’bells & whistles’; just a solid charger.

Nice work Blue…. :beer:

I am a little confused by this,

  1. Adjustable charging current (0,1A-3,0A) in 0,1A steps.

I am no expert but AAA sized cells need less than 1 amp for charging?

That is 0.1A - 3.0A in 0.1A steps

0.1A = 1/10A …… :wink:

That’s a tenth of an amp. In some countries written as 0.1 while in others as 0,1.
And that was already updated, the range is said to start at mere 50 mA to work better with 10180 cells.