NEW! Redilast Mini USB Li-ion Charger! CC/CV 500mA

Commercial Sellers' Spot
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Hi Guys,

I’d like to introduce you to a brand new product, our very own Mini USB Li-ion Battery charger. This charger was in the works for about 2 years, but kept being put on the back burner (due to other projects). I designed and had the circuit boards made up over a year ago, just never got around to putting some together and listing them up for sale! These are quite time consuming to make due to the tiny enclosure they have to fit into. Well, they are here and they are sweet little chargers! Laser engraved aluminum case, CC/CV charging IC with 500mA charge current can charge most cells out there! I tested IC’s from 3 different companies, and also found most of the IC’s from China were fakes, and performed poorly, so I bought all the IC components from the USA. I also found most of these IC’s when you connect a battery backwards, the charger literally smokes and burns out the IC. So I built in reverse polarity protection. The PCB is assembled in China, the final soldering of the wires, alligator clips, thermal compound application and enclosing the unit in the aluminum case is done in the USA! Enough talk, now onto some more details and pictures! :smiley:

Features & Specifications:

  • CC/CV (Constant Current / Constant Voltage) Charge Method
  • Thermally Regulated (automatically reduces charge current if needed )
  • IC is heatsinked to the aluminum USB case for maximum performance
  • Works on any 500mA capable USB port (99% of computers)
  • High Charge Accuracy (4.20v ± 0.03v)
  • Reverse Polarity Protection
  • Short circuit Protection
  • Soft start charge current for overdischarged cells (10%)
  • ~40mA charge termination current (CV stage)
  • Blue LED indicator turns off when charging is complete

Description:

The Redilast Mini USB Charger is a full featured USB powered CC/CV Li-ion battery charger. The charger with the included magnets can charge a variety of cells of varying sizes and capacities including: (14430, 14500, 14650, 16340, 16650, 17360, 17500, 17650, 17670, 18350, 18500, 18650, 18700, 26650 etc). Only charge cells with a capacity of 500mAh or greater, or you will exceed the recommended maximum charge current of most Li-ion cells which is 1C.
The standardized USB connection allows charging in a variety of locations: from a desktop computer, AC outlet USB power supply, USB 12v Car charter, solar panel or even from a portable laptop or power bank. This versatility makes this charger the ideal choice to take with you on the go.

Approximate Charge times:

RCR123 — 1.5hrs.
14500 — 2hrs
17500 — 3hrs
18500 — 4hrs
18650 — 7hrs
26650 — 10hrs
*Depends on cell capacity, state of charge, and power source.

Pictures:

Introductory price of only $19.99!

Redilast USB Li-ion Charger

Also: Order $80 or more of Redilast batteries from edcplus.com, and mention “USBCHARGER” in the order, notes and we will send you a charger for FREE!

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Typo?

I wouldn’t call 3.90V-4.50V termination voltage too accurate or safe.

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Yes, should be 0.03. Edited.

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It doesn’t look like a brand new product.
An identical looking usb li-ion charger has been out in the market place for some time now.

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Are you referring to cotton pickers? If so, these were actually made long before he made anything similar to these with the USB cases. Also, this actually has a custom made charging circuit, not an off the shelf charging board with the cheapest TP4054 IC on the market.

The case is just a generic USB case, I can assure you the internals are completely custom and went through 3 versions before the final product was ready.

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Can you show us the insides?

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And supported USB 3.0 (1 amp) perhaps with switchable current settings for smaller cells, it would definitely be worth considering as a travel charger.

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How much does it weigh?

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I was very kindly given one of these to test a few months ago. I keep it in my EDC backpack, which I always have with me. I have used it quite a few times while driving and at my desk at work to top off an 18650 or 16340. I’ve been very happy with it. It is easy to use, works on almost any battery, is idiot proof, and makes it so I never have to worry about running down my lights on a vacation, camping trip, at work, etc. It is nice that I can charge my batteries right off my computer’s USB port, which allows me to keep an eye on them. I also appreciate the fact the LED on the charger is not annoyingly bright like a lot of LED’s are these days. It is bright enough to easily see, but not so bright that it catches your attention. The magnets are very strong and have had absolutely no problems staying securely attached to any of my batteries, even my protected Fasttech NCR18650B’s, which have chintzy protection circuits.

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It looks nice and I like that you have added reverse polarity protection and heatsinked to the case (Usual these IC's throttles the current, because they get hot).

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I don’t want to post a picture of the internals, as it would be too easy to reverse engineer. Lots of manufacturers watch these forums… This is not an open source project.

The idea behind this was to make a charger that could charge 90% of the Li-ion cells in your collection. 1A would be too much for CR123/14500 etc. Secondly, the heat dissipation of the aluminum case wouldn’t be sufficient for 1A. Lastly, not all USB ports put out 1A. USB 2.0 specs call for 500mA+, most computers currently don’t have USB 3. Of course its possible that I would consider releasing another version in the future thats different, but have no plans as of now.

Very light less than 20g, 1oz with the alligator clips and magnets.

Thanks glad you are enjoying using your charger!

Yes, those are two very important features that most designs lack (even the reference designs for most of these IC’s). I tested and instantly destroyed a couple of the TP4054 IC samples I tested when I reversed the polarity. The bottom of the PCB board touches a large aluminum plate which touches the case. Arctic Alumina is used. You can feel the case get reasonably warm when charging lower voltage Li-ion cells like <3.5v, then it cools down as the cell voltage increases and less heat is dissipated. If this type of heatsink was not used initial charge current could be <250mA in my testing.

A couple of tests I did:

You can see the thermal management working throttling down the charge current slightly to around 400mA during the first 20 minutes or so of the charge cycle. This will only happen if the battery is very discharged (3.20v in the above test), or if the USB voltage is above 5v, there will be a little thermal regulation during the start of the charging process. This is done to protect the circuitry.

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If you want some independent tests, I would like to test it and add it to my charger reviews.

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Yes, thanks I will probably contact you soon.

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Ordered. I’ve seen similar chargers, but they never seemed as refined, or didnt come with any wires or magnets, or were just raw circuit boards.
I need another charger like I need another hole in my head, but I like gadgets, and your gadget has appeal.

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Thanks, your order along with a few others have shipped. Enjoy! :slight_smile:

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Can you let me know what freight would be to Australia :slight_smile:

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About $6. You can calculate it on the site, thanks. I can also send it for about $2 as a flat (but couldn’t send the magnets or plastic case).

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You might want to update your website too.

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I got mine today. It’s even nicer in real life. The quality is there, and it shows. Where did you get those nice little chromed cube magnets.
I was thinking about a small container to put in so it wouldn’t be loose in my bag. The answer came in the mail, along with the charger.

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Cube magnets here or here.