--> FS: Cottonpickers Chargers incl. Worlds smallest Li-ion charger with display

[cottonpickers]

Worlds Smallest Charger in the World with Built in Voltmeter

This is a combined voltmeter and li-ion charger in one with multple current levels to suit different sized li-ion cells.

Use it to quickly check li-ion battery voltages, and if low just plug it in to a usb socket to charge them -Its neat watching the voltage rise in real time plugged in to my laptop usb socket. The voltage meter will show voltages from 3v to 25v so is perfect to let you know when you've overdischarged a cell.

Note this is for 3.6v / 3.7v rechargable li-ion cells, not 3v rechargeables, primaries or nimh. Never leave cells charging unattended. If you don't know the dangers of li-ions cells and proper management please don't purchase.



Charger details:
The USB Charger is suitable for rechargeable 3.6v /3.7v li-ions that get charged up to 4.2v (The 4.35v CC/CV charger is Only suitable for specific cells of which there are only a couple : eg Samsung ICR18650-30A)

* It will taper the current as full voltage is reached. (so you get to 4v quite quickly, and a slower finish to the charge)
* CC/CV charging algorithm
* Uses a soft start for cells below 2.95v applying 10% current until 2.9v is reached.

See the graphs below for typical charging times, and how the charger typically operates:




FAQ:
What integrated circuit is inside these chargers? If it doesn't have a display it uses a Chinese TP4054. If it has a display I upgrade to the USA LTC4054. The 4.35v specialist charger uses a Microchip MCP73831
What range is the voltmeter good for? Range is between 2.8v & 14.6v
How accurate is the voltmeter? Its rated as accurate to +/-0.005v my tests agreed
What is the current draw of the voltmeter? Its about 10ma
Will my laptop deliver More than 500ma?: Many do, but I can't guarantee yours will. Ask for a 480 model if you are unsure or use a 'walwart' charger capable of the current you need else you risk going outside the spec of the port
Do I need to plug the charger in to see the voltage?: No
What happens if I connect the battery the wrong way around? Its important that you connect the charger the right way (red to positive) otherwise it will damage the charger
What happens if the two leads touch whilst plugged in? I suggest you connect the charger to the battery before plugging in, and unplug before removing the connectors. This then prevents you leaving it plugged in with no battery connected. If you leave the charging magnets connected together without a battery and leave it plugged in it will eventually break the charger. (accidentally letting them touch whilst plugged in doesn't immediately break it, but you should get into a good habit.)
What if I move the switch whilst charging. You can move the switch on the fly and it will move eg from 90ma to 320ma to 620 and back - If you do this on a small cell you risk damaging it by giving it too much current..
Is the cell fully charged when the display shows 4.2v? No, the charging algorithm means you'll see 4.2v or 4.21v on the display for quite some time before the cell is fully charged. See the graphs to see what you should expect to see on the display.
How do I know when its finished charging? There is a small secondary LED at the back that goes out. Of course you can stop the charging early if you wish by unplugging.
Can I use this with your solar panels? You can, but I recommend the 'Basic no display' version see here for reasons:
You use magnets to connect to the battery - Are all batteries magnetic? No, some don't have magnetic ends. Some Redilast will have issues & Yezl 18650. Before you purchase, take a magnet and check your cells have magnetic + and - ends. Most do, but not all -let me know any that don't so I can add to this brand list!
What current setting do I need? The maximum charge rate is around 1C for most cells. So a 350mah 10440 should not be charged faster than 350ma. Many people recommend a lower rate (0.6C) to prolong battery life. This means a 10440 would have an 'ideal' setting of around 210ma.
What leads come with your chargers? The basic chargers without the display come with one set of leads with Magnets soldered to the end. All the chargers with the built in voltmeters also come with Croc Clip leads with small magnets supllied in the jaws.


All the prices below include Paypal fees and international shipping (Not tracked) I will resend any lost items at my discretion. If you need to add a 'note' to your order you will need to manually pay in paypal rather than use these links.

Basic Chargers	These are amde from aluminium and use a Chinese TP4054 IC which isn't as accurate as the USA version present in the chargers which have a voltmeter. Add to Cart: 100ma Basic Charger in silver -$17 Add to Cart: 200ma Basic Charger in silver -$17 Add to Cart: 300ma Basic Charger in silver -$17 Add to Cart: 400ma Basic Charger in silver - $17 Add to Cart: 500ma Basic Charger in silver - $17 Add to Cart: 600ma Basic Charger in silver -$17 Add to Cart: 700ma Basic Charger in silver -$17 Add to Cart: 100ma Basic Charger in RED -$19 Add to Cart: 700ma Basic Charger in RED -$19 Add to Cart: 100ma Basic Charger in BLUE - $19 Add to Cart: 700ma Basic Charger in BLUE - $19 Add to Cart: 100ma Basic Charger in BLACK - $19 Add to Cart: 700ma Basic Charger in BLACK - $19
Double Current Chargers	A simple switch toggles between two current settings. Common settings below. These all have USA upgraded ICs and a built in Voltmeter Add to Cart: Dual 480ma / 700ma Leftie -$39 Add to Cart: Dual 90ma / 200ma Leftie - $39
Triple setting charger	A simple switch toggles between three current settings. Common settings below. These all have USA upgraded ICs and a built in Voltmeter Add to Cart: Triple Leftie 90ma/320ma/620ma - $44 Add to Cart: Triple Leftie 90ma/320ma/700ma - $44
Quad Setting Charger	A simple switch toggles between four current settings. Common settings below. These all have USA upgraded ICs and a built in Voltmeter Add to Cart: Quad 90ma/300ma/480ma/700ma - $54
'Octa' Charger	8 Current Settings: 50ma, 100ma, 200ma, 300ma, 400ma, 500ma, 600ma, 780ma Add to Cart: Octa Black Rightie -$59	$59
High Current Chargers	These all require a high current (2 amp) USB socket. Most computers are unable to supply enough current. Add to Cart: High current 500ma/1200ma Black Rightie - $49 Add to Cart: 500ma/700ma/1200ma Black Rightie- $54 Add to Cart: 500ma/1000ma/1200ma Black Rightie - $54
4.2v / 4.35v Charger	This is a specialist charger - Most 18650s will be damaged with this when used on the 4.35v setting. Only VERY limited number of 18650's are designed to take this 4.35v setting. If you don't know for SURE that your your cell is compatible, please do not purchase. 4.2v setting set to 500ma ; 4.35v setting has max 1000ma (dropping to 500ma at 4.2v) Add to Cart: Dual 4.2v/4.35v Black Rightie - $49
18650 Cradle	This is a cradle for 18650's suitable for all chargers with built in voltmeter. Particularly good with the Octa charger as it ensure you get the polarity correct. Only available when ordered with a charger Add to Cart: 18650 Cradle - $7

If you want something different to the above, you can Post to the thread, PM me or Email me at This is also my paypal account. Changing any of the current settings is easy and not chargeable. I can also swap Leftie's for Righties etc. If you know what you need and can specify it , I'm fine with you doing that directly in paypal with a paypal note. If something isn't right I can email you.

[biker1]

I miss the other thread j/k

This thread is Simple, and to the point.
I wish you much success

[afraidofdark]

I have a v1 charger with display, as well as a basic charger + large solar panel. Consider me a satisfied customer, I use this stuff all the time (in fact I'm using the panel + charger as I type this ).

The chargers are very small and very convenient and work perfectly.

[RocketTomato]

What happens if your laptop cannot deliver the 620 mA? Will the laptop just deliver as much as it can or will it not charge at all?

[DM51]

Do you want me to close your other thread? You can't have 2 threads selling the same item - it just causes confusion (and it is a contravention of Rule 9).

[cottonpickers]

Yes please, thx

[DM51]

Done.

[cottonpickers]

RocketTomato: I tested on my netbook, and dell laptop and they both (surprisingly) delivered the 620ma just fine. If your PC can't support more than 500ma then the most likely outcome is they will either deliver 500ma or possibly will temporarily switch off the port until its rebooted. If you have an external hard drive or similar you could always see what happens if you plug it in with only one usb lead and not two (assuming you have something with one of those Y leads to let you join the current from two ports.

Many PCs now support higher current than the 500ma- usb3 certainly will as the standard is now 900ma for that.

[gunga]

Would it work if we simply plug it into many of the common usb chargers (you know, like ones used for iPods or iPhones)?

[cottonpickers]

gunga: Yes, works with any USB port (eg car usb port, walwart usb port used for many phones etc) These usually can deliver 1000ma which is an advantage.

[RocketTomato]

Cotton, your PM box is full.

As far as my charger goes, let's do 150/300/620 mA. Thanks!

[biker1]

Just picked up my Worlds Smallest Li-ion Charger with Display, and it's working Great!!
The leads with the alligator clips and magnetic balls are the best version yet!

I am very Happy, and again, I want to thank you cottonpickers for your Persistence, and Fantastic work. A job Very Well Done

Oh, and thanks for the USB Car charger


UPDATE:

- I charged my AW R123 cell, and after 40 minutes, the end voltage was 4.2V. I removed it from the leads, and after a minute or so, the voltage read 4.17V which is fine. (I since read in post #1 that if I left charging when it says 4.2V, the voltage inside the cell will continue to increase)

- I am charging my AW 18650 2900mAh cell. Starting voltage was 3.87V, and it has been on 4.1V for 40 minutes. I am trying to read through the previous thread to find the voltage the charger cuts off at, but it is hard to find the exact posts. I know the 2900mAh will take longer to charge, but is stopping at 4.1V the norm, or will it take a couple of hours to get it past 4.1V with the setting on 620mAh? I think I remember something about lowering the setting on the charger to 90 or 320mAh to get it past 4.1V, or something to that effect.
----I just checked the charger after reading your 1st post, and noticed the led light was 'out' in the back, and the voltage read 4.1V. I removed the leads, and the red light came on. I then connected the leads, and the red light went off. I repeated the lead removals and switched the settings, and then back to 620mAh. This time, the red light came on and stayed on, and the v reading said 4.17V. A few seconds later, the red light on the back went off, and the voltage now reads 4.10V. I am a little confused as to what is happening.
------I removed the leads a couple of times, and placed them back on the cell. The red led on the back is now on, and the v reading is 4.18V ?? The led just went off 30 seconds later, and the v reading is 4.11V.
I am trying to be as detailed as possible with my observations to help see what is occurring.

----I just connected the charger back to the usb port on my laptop from the wall usb charger (plugged in the wall charger for a few minutes, where the voltage remained @ 4.11V.)
----The red led on the back is now lit, and the voltage on the display says 4.19V.

It appears that when the leads are attached to the cell, the charger charges sometimes, and sometimes not. I then have to remove and then reattach the leads until the charger starts charging again.
I am leaving the leads alone, and the charging has been stable for the last few minutes. The red led indicator light is on and the display is reading 4.19V.

Update >

-----The above 18650 2900mAh cell came off at 4.16V, and is fine.

-----I have an R123 @4.10v and an 18650 2900mAh @ 4.05V and I can't get the red led on back of the charger to light up at all now.
I just checked again, and the red led on the back is very dim, not completely 'off' like when I remove it from the usb port.

[hotlight]

any plans on lowering voltmeter reading? (to test nimh...)

any plans to be able to charge nimh+ Li Ion?


can I charge x2 Li Ion at the same time?(using a magnet in between the 2 cells).... *so I can keep the set balanced*


sorry if this has been asked before.
great product, need to pick one up.

[Rexlion]

hotlight, 2 li-ion cells in series would be double the voltage. This unit only charges to about 4.2v.

[cottonpickers]

Biker1: Per your PM, yes please let me take a look. I understand some of what is happening on your post (for example, whenever you charge a cell which is about 4.1v , the voltage reading will immediately jump to around 4.17v, and when the charge current is removed it immediately drops back - This especially occurs the higher the voltage) But let me give it a good look over to understand.

[biker1]

I sent you a pm, and will be shipping back the chargers to you.
I appreciate you posting another one to me.

Thanks again.....

Update:
Chargers shipped back.
PM sent....

[afraidofdark]

Cottonpickers, I sent you a couple PMs about replacement leads on Sunday, have you received them?

[cottonpickers]

afraidofdark: Yes, got them. I think there must have been a PM issue as I did reply. Leads went in the post on 31st, no charge -so hopefully will be with you on Mon or Tue.

[afraidofdark]

afraidofdark: Yes, got them. I think there must have been a PM issue as I did reply. Leads went in the post on 31st, no charge -so hopefully will be with you on Mon or Tue.

Thank you so much! That's very kind of you

[malakye666]

Hey Cottonpickers
Would like to order the newest version of your charger for a left hand port. default settings. and could you put some shrink wrap on the magnet cables for me if not thats fine. If you could pm details I will PP directly thanks mate hope all is well with you and yours.
Cheers Tim

[Romanko]

How much time it will take to charge AW's RCR123A 750mah with Basic No Display Charger 400ma? And what is better to take Basic No Display Charger or Charger with Display?
Which one charge better? Or the difference only in Display?

[nfetterly]

Looks great, email sent.

[cottonpickers]

Malakye: PM sent

Romanko: The charging circuit in the triple follows a true cc/cv algorithm which is recommended for li-ion cells. The basic charger follows a similar algorithm at low currents (eg 60ma) but can't be called true cc/cv especially at higher currents. (effectively I 'upgrade' the charging circuit when I build the triples. by replacing the original integrated circuit)

The triple has the unique selling point of the built in voltage meter and different current settings for different sized cells. Having the 620ma setting means it will charge a rcr123 in around 1.5-2 hours whereas the basic unit will take 2.5-3hours I would think (due to 400ma current)

I can also tailor the solution a little by putting a display on a basic charger if you are interested. This would be cheaper than the triple -Please PM if you think that may interest you.

[biker1]

An observation >
I am very pleased regarding the charging of my AW RCR123 cells with the World's Smallest Charger, as compared to my Pila Charger.
The cell comes of the Pila @4.11V, while the cell comes off the 'World's Smallest Charger' @4.15V ( and that's because I removed the cell a little sooner after the display read 4.2V) If I would have left the R123 cell on charge longer, it would have charged even more.
The units are both cc/cv, but it appears the Worlds Smallest Charger charges the cells a little more. The same is true for my 18560, 2900mAh cell.
Oh, and in addition, the World's Smallest Charger has an on-board LED Display which is a huge plus!

[Romanko]

An observation >

The cell comes of the Pila @4.11V, while the cell comes off the 'World's Smallest Charger' @4.15V ( and that's because I removed the cell a little sooner after the display read 4.2V) If I would have left the R123 cell on charge longer, it would have charged even more.

Does it mean that I have to monitor the charging progress ?

[kaptain_zero]

Just an observation I've made regarding the terminal voltage of LiIo cells. I too felt for some time that a cell that comes off the charger at 4.2V obviously has more charge than one that comes off at 4.1V but I never really knew just how much.

Well, I recently received in the mail a "hobby charger" that allows me to set it to either charge to 4.1V or 4.2V with liIo cells (it's a fudge really because to get to 4.2V I have to tell the charger that it is charging a LiPo instead of LiIo and in practice, only the terminal voltage differs between the two). So I set out to charge a ~600mAh RCR123 to 4.1V which went as expected. I then reset the charger and told it to charge to 4.2v using all the same settings which meant it would continue to charge briefly in CC mode until it reached 4.2V and then CV until it reached 1/10th of the initial charge current. The end result was that the charger added a total of 14mAh input to raise the battery up to the 4.2V level. On a 600mAh battery, an additional 14mAh input would result in perhaps 10mAh of extra capacity.... which does not go very far with a high draw flashlight!

The moral as I see it, is to not fret over the terminal voltage of your particular charger. If it does the proper CC/CV and you end up at 4.1 instead of 4.2, the difference is very very small on an RCR123 and not enough to make any significant difference if you are sizing your battery correctly and never using it to full capacity before recharging. Overcharging on the other hand, needs to be avoided at all cost, as does over discharging.

So to me it sounds like both your chargers are working just fine and in real world use, either charger would serve you very very well.... I'd give the edge to the USB charger as there always seems to be a USB port nearby, and it takes up a whole lot less room than a Pila.

Regards

Christian

An observation >
I am very pleased regarding the charging of my AW RCR123 cells with the World's Smallest Charger, as compared to my Pila Charger.
The cell comes of the Pila @4.11V, while the cell comes off the 'World's Smallest Charger' @4.15V ( and that's because I removed the cell a little sooner after the display read 4.2V) If I would have left the R123 cell on charge longer, it would have charged even more.
The units are both cc/cv, but it appears the Worlds Smallest Charger charges the cells a little more. The same is true for my 18560, 2900mAh cell.
Oh, and in addition, the World's Smallest Charger has an on-board LED Display which is a huge plus!

[kaptain_zero]

Does it mean that I have to monitor the charging progress ?

No, the WSC as well as the Pila will both terminate the charge when they reach the end of the CV portion of the charging cycle, unlike many other cheap chargers. Biker1 just took the battery off before it finished charging because he wanted to, not because he HAD to. But yes, you DO have to monitor ALL LiIon chargers or at the very least place them in a fire safe area..... Something can go wrong with these types of cells, no matter how careful you are. It's the nature of the beast.


Regards

Christian

[Romanko]

If I will use it in usb 3.0 it will be ok?

[Kaichu Dento]

If I will use it in usb 3.0 it will be ok?

Yes, 3.0 is configured to still allow older USB devices to operate.

[Romanko]

Does Worlds smallest Li-ion charger with display use inside USB 2.0 chip?