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

Concerning the discharge feature, I agree with the big axial fan at the bottom idea. However, the charger chassis should or needs to be designed in a way that the fan's air intake may not be inadvertently interrupted. Making the charger a bit taller and setting dual air intakes each side or top and bottom definitively solves this if properly done. So be it imho.

BluewordM, please edit the opening post and change the input voltage compatibility to something like 7V - 30V. Let me also say that this charger may require a very high amount of power when charging at 3A per slot, probably close to 60W. So, I believe it could be better served by a 19V - 24V power supply, similar to the ones bundled with laptops, mainly to alleviate current losses in the cable.

Sun, 08/25/2019 - 00:09

Of course. Never said that full power could be achieved with anything less than 12V.

(5-10V) is the range in which the charger will stop charging, but not completely turn off.

Looking forward to seeing this product come to market!

Will the requirements definitions (document) address accuracy tolerances, safety features, robustness/reliability, assembly quality, QC practices, etc.?

It’s often left to the manufacturer to do this but it can cripple a product if not done well enough, or to the level expected by the community. Defining it up front can also help with the cost analysis and any necessary adjustments to the feature set or MSRP.

No worries Mooch.

I’ll be starting serious discussion with manufacturers about manufacturing and the other stuff Monday.

Say, what made you come up in this forum?

Been a lurker at BLF for far too long!

My apologies for just diving in like that with concerns.

Barkuti posted about the charger over at ECF (electronic cigarette forums) and I was quite excited to see this project coming to light. I had to chime in to say I think it’s a fantastic idea. :slight_smile:

Nice to see you Mooch. Been in the e-cig forums for years. Always enjoyed your candidness with these battery manufacturers. How many years ago was the efest fiasco? lol

Agree. Many laptop power supplies use such standard plug, it could then be powered by a typical 19V 65W/90W brick. The charger could be sold with or without power supply at different price points. LiitoKala does this.

I for example have many “retired” quality laptop bricks which I could easily convert to ∅5.5 × 2.5mm plug if needed.

Of course what I'm trying to imply here is that, with such long list of charger features and a minimum of quality, what manufacturer is willing to make a device which such potential to cannibalize its own products? The ones who already have good chargers at beefy price points may not.

A quality charger with so many features and an expensive power brick at $49? Maybe a little more money would be more realistic. Or a tiny bit less without the brick.

LiitoKala may want to go with this. They do not have a high end charger, thus 0% chance of cannibalization. Careful negotiation may be due to make 'em understand the quality and feature requirements. Also, if they were to want to make a cut-down version later, I'd at least tell them to name it differently.

DLYFULL is also a good candidate. This would turn out to be their “flagship” charger or sort of. Careful negotiation is due too.

By the way, to ensure proper cooling of cells their slots may need some holes or slot gaps on the floor.

Sun, 08/25/2019 - 05:31; Sun, 08/25/2019 - 05:34

OMG…that Efest fiasco. Such a fail on their part.

I’m unaware, what was that about?

+ 1

Efest had some spectacularly overrated cells that I tested and called them out on. They tried to rebut my conclusions with some technically pitiful statements and a laughable video and then tried to attack my integrity and discredit me. They had no idea how a battery rating was set.

And they totally miscalculated the massive backlash they received from it

I remember that now!

I think that's when I learned Mooch's name.

@BlueSwordM:

Sorry for bringing this back to attention once again but is my request from ► here ◄ reflected in the feature list? In terms of safety when charging LiFePO₄ I'd really appreciate a charger that not automatically (re)starts with a 4.20V default. So, requiring a "push button xyz to start charging" would be a nice and inexpensive add on. :-)

On a side note: Should you or the manufacturer need any help with native German language support for the manual, let me know.

Cheers,

Thomas

I doubt a charger would restart with a different chemistry/voltage setting unless power is cycled, which is wrong anyway. Charger restart sucks butt. As an example, according to HKJ reviews LiFePO4 restart is set so high in TP5000 DIY modules (old blue, newer red) that it keeps knocking on/over the battery.

I can say the same for (Castillian) Spanish. :-D

Presuming ≈85% efficiency for the internal buck converters let me say power consumption will indeed go well above 60W peak. 24V 3A power supplies are common (and relatively cheap).

We have to watch out for going too high in voltage though as it increases parts costs (due to their higher voltage ratings) and a higher input-to-output-voltage-ratio can be more expensive to design for. Voltage spiking from plugging an energized power supply into the charger will be more severe too and the supply’s switching duty cycle range can be limited with a high in/out voltage ratio. This limits the possible output voltage range of the supply.

Planned input voltage range for this charger goes up to 30V, to make it compatible with industrial vehicles.

I must admit that “high current” via a standard 5.5 × 2.5mm DC plug creeps me out a bit, already seen many shoddy plugs of that class. HP's 7.4 × 5.08mm DC power connector is a lot better, imho.

@Barkuti, 30V compatibility was not made for vehicles.

It’s been made from a suggestion from a prohiminent member from SecondLifeStorage.

This below?

Who cares anyway. Lets make it good.