MTN Electronics: LEDs - Batteries - Lights - Chargers - Hosts - Drivers - Components - 1-Stop-US Source

@ FT

mini c8

or

mini c8

I’m glad you posted this. That changes my plans for my build. Now I’m going to look for a different host. I’ll have to see at Christmas what my wife bought me from RMM and go from there.

I don’t know where this one came from, it was a gift to me.

It’s branded Guolin with GL-037-86 and 3W, even though all the literature says 1W. Need to change mine to 10W. :wink:

I got my mini C8’s from FT. They work, but they are pretty much junk stock. Not much more than a tiny host at the… $2.80 or w/e I paid per.

Btw batteries and assorted misc arrived today. I thought part of the order was missing “Why did he include this tiny box of foam” and then started pulling out foam from the cutouts and it was like a surprise miniature christmas present unwrapping.

A bunch of orders from other vendors arrived today as well… now I’ve got a pile up of parts and no idea where to start first. :bigsmile:

Unknown, start at the beginning, makes it much easier than starting in the middle and having to back up to go forward. :wink:

The parts you forgot why you ordered? Those are for me, just forward them on over here and I’ll sort em out for you…

New:

  • Convoy M1 Host
  • 4 x 18650 DIY USB Battery Box (no charging circuitry)
Re-Stock:
  • Convoy S2 Host
  • 20mm Partition Board / Contact MCPCB
Monday 12/23:
  • Lots of Noctigon Stuff (everything except for more T6-4C)
  • Qlite Drivers
  • Nitecore i4 Chargers

Ok guys, beyond the adjustable LM2596 I have been on a small quest to find an inexpensive and simple charger (under $3.25) for the 4.35v cells. I have played with a few different ideas and have finally settled on something that meets those goals. You might think it's goofy, but it works well! I have tested it several times with the LG D1 cell, measuring charge current and voltage along the way. Charge starts at around 0.3A at 3.9 volts and gradually works it way down to nothing when the cell hits 4.36v, where it has consistently terminated, a decent CC/CV charge curve. The best way to use this charger if you're in a hurry is to charge the cells to 4.2v in a faster charger then finish it off with this. Any guesses as to what it is? A YiboYuan Samsung Galaxy Note 2 external battery charger! That phone comes with a 4.35v battery from the factory. No need to open up the internals of the charger, you can use alligator clips or solder directly to battery contact prongs. Cheap enough to have a couple :)

Did you crack one open to check what chip its using?
:ghost:

Re-stock time for Protected Panasonic 3400mAh 18650s? Estimate?

thx

Hopefully by next weekend.

As to the chip, I did take it apart and couldn't find anything identifiable in there. I was going to adapt the MCP73831 chip to one of the existing boards, but the parts alone are more expensive than this entire charger. Sure, it's a bit slower but really not too bad. The faster solution is still the LM2596 buck board, but this works with no adjustment and no external power supply.

Honestly, I wouldn’t recommend cheap AC powered chargers sold direct from china. :~ Often they just don’t obey any laws or regulations concerning safety.

There is a usb powered 4.35v external battery charger for the Samsung Galaxy S3. Its $6 but it doesn’t carry the danger of cheap chinese AC powered devices. Wouldn’t need to go through the adjustment of the LM2596 boards. With a usb charger like this Galaxy S3 one or a MCP73831/2 you can add a tp4065 or other usb charger in parallel to boost its current. One of cottenpicker’s chargers does the same, using a 4.2 chip in parallel with a 4.35v chip.

Good idea RMM. When I started looking at the 4.35v cells I got hung up on the fact that there must be charging ICs for use within phones which use 4.35v cells. A retrofit with an MCP73831 was all I could think of, cost made me give it up. External chargers never crossed my mind!

For more current, maybe we should try the Yiboyuan SS-1 AC, which states 600mA. Yiboyuan has at least 3 different 600mA 4.35v chargers, but the SS-1 seemed least expensive.

I’ve seen others doing that charger swap you mention to speed things up, but I wonder what effect it has. It seems to me that doing a complete CC/CV charge to 4.2v and then starting over with CC/CV to 4.35v might do something undesirable?

Doing a full cc/cv 4.2v charge then switching to a 4.35v cc/cv won’t do any harm. Its just slower & sort of annoying.

I’ve never fully understood exactly what makes a CC/CV charge cycle so good in the first place, so I wasn’t sure.

Is it simply that the CC phase protects the cell from overcurrent and CV kicks in once we reach the maximum voltage for the cell? Would a pure CV charger result in anything undesirable other than a slow charge?

All CV would give a faster charge - too fast. Say you start with a resting voltage of 3.6v, if you apply the full charge voltage across it at that point, the cell will accept many many amps. The CC phase is required to limit the current until the difference between the actual cell voltage and desired finish voltage are closer together. Less spread between actual & desired self-limits the current to a safe range, so holding a constant voltage just a tad over the desired full charge voltage until it finishes is fine.

When I manually charge the 4.3v cells starting from 4.2v as they come off the hobby charger, it's all CV as that difference between 4.2 and 4.3 is small enough that limiting the current isn't needed to stay in a 'safe' range. It limits the current on its own.

Duh, brain fart. First I write that CC clamps the current to protect the cell from overcurrent, then I suggest that CV only would be slow…. clearly a lack of thought. Thanks!

Are you trying to suggest we’re hi-brow here ?
Last thing we need is to become a clone of that other place :wink:

Will have to try one of those next :) Just wanted you to know that this has been the best one so far (I've tried a few others). I have used Yiboyuan phone battery chargers for years with my Droid X and now HTC Rezound, no problems with them whatsoever.

FYI:

More small flashlight holsters in stock, along with the butterfly style XM-L emitter spacers.

Here we talk freely and openly, which inspires suggestions and innovation. Like what Richard is doing with the 4.35V chargers and the feedback.

You don’t have to be on here long at all to have people run amok in your thread, but they most always come back around. :wink:

Richard, any sign of the Convoy C8’s ? No hurry, just wondering.

Indeed, should see them something this next week.

About the charger, no it isn't the most eloquent solution, but it works great and has been reliable. Besides, this is budget light forum, right? I have been testing it all week long to make sure that it was good to go before announcing it here. None of the other solutions I've tried or looked at up until this were going to be cheap enough to be worth it, to me at least.