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DIY 18650 20 bay Arduino managed Charger
#11
Legit ones have the big TP in the upper left corner and the lettering is very clearly visible. If the TP isn't visible and/or the text is very faint (needing a mag lens and light to see it), it's probably a fake (especially if the TP isn't there)


This one is most likely fake


This one is legit. See the TP logo in the upper left corner?
LEDSchlucker likes this post
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
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#12
Actually no, but i will look when they arrive, i take it the fake ones dont work or work badly?

I contacted the company I bought the LittoKala 500 II from, they are sending a replacement, no need to return old one.
So because I dont have to send it back, I did what everyone does, I pulled it apart to find out why it died if possible.

2 out of the 4 ss34 Schottky diodes are cooked. 0.342 cents each or less than $2 for 10. dunno if its worth the effort, diodes dont die without a reason... meh, might try anyway. It would leave me always wondering What-If.
YOLO is wrong, You live every day. You only Die once so it should be YODO. Angel
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#13
i read that an Arduino mega will run on 12vdc, however a few posts on various sites say they dont fully recommend it.
So I have ordered a adjustable DC-DC Buck converter, I will set to to give 9VDC and add 1 or 2 1000uF electrolitics just to get the smoothest 9VDC supply.
YOLO is wrong, You live every day. You only Die once so it should be YODO. Angel
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#14
(02-20-2019, 11:16 PM)Gremlin Wrote: BTW my liitoKala 500II bit the dust last night... grrrrrrrrrr.

Can you donate it for the greater good/science?
No. cells
Indexed: 53
Processed ok, not yet indexed: ~3200
Broken down, untested: ~0
Not yet broken down: ~200 kg
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#15
(02-26-2019, 12:39 AM)Gremlin Wrote: i read that an Arduino mega will run on 12vdc, however a few posts on various sites  say they dont fully recommend it.
So I have ordered a adjustable DC-DC Buck converter, I will set to to give 9VDC and add 1 or 2 1000uF electrolitics just to get the smoothest 9VDC supply.
The Arduino has a linear voltage-regulator on board. It reduces the voltage from the "Vin-pin" to 5V.The thing is, the excess energy is waisted  as heat. So when feeding in 12V and 500mA the output is 5V and 500mA so 3.5W of heat. That's why it is not recommended to feed 12V dc into the Arduino. The best way is to use the Buck-converter to generate 5V directly and feed it into the 5V pin. This way, you get an efficient power-supply. The additional caps are not necessary but its a good addition to get a more stable voltage.
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#16
How bad are the fake's? I think i ordered the fake ones.
Or what they don't do that they actually must do? and vica versa?
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#17
(03-04-2019, 06:49 PM)100kwh-hunter Wrote: How bad are the fake's? I think i ordered the fake ones.
Or what they don't do that they actually must do? and vica versa?

I've Used the "fake" ones. For my small batch (20pcs.) I could not find any dangerous differences to the real ones. The Charging current is not exactly 1000mA but that could be due to low tolerance resistors. The maximum charge-voltage however was always within the Specs of the data-sheet. I use them in some Projects where they are soldered to phone-batteries (they might have build in protection) and so far everything looks good. You should check the end-of-charge-voltage by connecting an electrolytic capacitor to the output of the TP4056 and powering it up. As soon as the chip says the cap is charged, check with a multimeter if the voltage is correct.
I can not say how age or temperature effects the values but so far and for my applications I'm satisfied with them even if they are not genuine.
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#18
Hi guys, back with more information and updates on this Charger unit project. As per normal several things have been thought of or suggested by interested readers. This means YAU yet another upgrade.

OK the basic concept still holds true, however my idea for running 2 x 15w 10ohm resistors as a dump load has been thrown out of the window. Several reasons for this, bear with me as I run through the logic behind my thinking.
Here in AU those 2 wire wound ceramic resistors would have cost me $0.35 cents less than a HW586 unit. Now i am not rich and am trying to build this thing for a reasonable cost. My dad once instructed me on the principle of "penny wise and pound stupid" and I applied that here.
I have decided to go the 20 HW586 route for a few reasons (22 actually more on the extra 2 later).

Buying the HW units actually saved me a bit of money,
A) I no longer have to buy Oled displays to get some real time feedback of whats going on.
B) Although I had enough I2C resources to run several Oled screens, I have now freed those prossesing times and resorces for the Arduino Mega processor.
C) The sketch is just so much shorter to write and maintain.
D) the 20 mini Volt meters I ordered are now 15 too many. ( that will teach me not to be over enthusiastic)
E) This one is complicated:-
Using the 2x15w resistors would have worked fine, but would have needed the Mega to keep an eye on the dropping voltage and turn OFF the relay that selects between charge (tp4056) or discharge (Resistors). That would have tied up 20 data lines (or a multiplexer) to monitor this condition. The next problem would have been , as soon as the relay reset from the discharge path, the TP4056 would have seen a flat cell online and launched off to charge it again.
By substituting the HW586 for the resistors, I can now program how low I want it to discharge too, and once that figure has been obtained the HW unit simply switches off the discharge and nothing happens until I instruct the process to repeat.
Bonuses are the HW counts the capacity and displays it at a glance. The Mega is still writing these results to a excel sheet for permanent recording

Hope that was not too boring a read.
As for Vincents Reverse polarity Circuit contribution, I am just waiting for the arrival of he IRL540N mosfets. These circuits will be assembled on a 1" square vero board, then fitted into a 3d printed frame and poured with resin to seal them from harm and damage.

This is still a work in progress, I have a box that is slowly filling up with all the hardware I require. once everything has arrived then the layout will begin. Next post will contain the thinking and reson why I have increased the charger unit from 20 to 22 bays.

Mike
All comments appreciated.
Gummiadler likes this post
YOLO is wrong, You live every day. You only Die once so it should be YODO. Angel
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#19
OK new day...

As mentioned I have decided to increase the charg board by 2 additional bays, but these bays are "different" .
These 2 bays are going to be used for 0v cells that we all know and love soooo much.

My classification of a 0v cell , zero volt cell, is a cell that a commercial charger like a LiitoKala or Opus refuses to acknowledge when presented to it. It may actually have more than 0v, but not enough to trigger the charger(s).

Please remember I am a Newbie at this game and am still learning.
Now when I got my first few hundred cells, I sat at the bench slotting then into a Liito charger, if it recognized the insertion the cell went into one bucket, if not it went into another. When all sorted I had 380+ in the good bucket and way way to many in the other. This was initially rather disappointing.
Fast forward a few weeks of reading,video's, chatting and repeat. I grab the "bad" bucket and cobble up a "Dumb" charger system. Taking 20 random cells , one by one I hit them with a lab table top power supply set to 2.8v @ 1amp.
Each cell was timed in this "hard" charger for 10 mins.
Out of the 20 cells I got all 20 to be recognized buy the Litto unit, but, as you may already have guessed with varying results.

Of the 20 cells (red Sanyo's) turned into heaters and were placed in a new DOA bucket
13 others cycled 3 times over 2200mah
3 cycled to 1200-1600mah.
1 just tripped the short circuit protection of he Lab PSU.

Do I think I miraculously recovered a large percentage of 0V cells? Nope, I may be new, I am not dumb.

So *I* think I need to adopt a testing regime for these class of cells. Currently I am leaning towards this:-
3 x dump to 2.8v and recharge to 4.1v then Shelf time of min 14 days to test for self discharge or losses.
Then if they show little or nil voltage loss I can start to look on them as a possible use full cell.

That is the reason for the 2 additional bays on the charge unit, basically to hypothetically slap the cell into paying attention and find if its worth keeping or not. A second chance if you will.
Normal chargers wont do this, the TP4056 module wont do this, so I have designed two bays to play nasty with the cell.

I would love to hear what system others use to sort their cells. Is what I mentioned before a suitable regimen/system?

As always comment appreciated and welcome. Good or bad.

Mike.
YOLO is wrong, You live every day. You only Die once so it should be YODO. Angel
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#20
Gremlin,

Quote:I would love to hear what system others use to sort their cells. 
I sort my cells into 3 different categories. 0V to <2V, 2V to <3V and 3V+
Left to right
 

0V to <2V are initially resistance checked. If they are 0V and have infinite IR then the CID has popped and to the recycle bin they go.
If they have an IR of over 100mΩ they are set aside for further study but they generally don't give any good results other than the green sony GR series which for some reason the IR drops drastically if slow charged.
I gather 20 cells of very similar V and put them into my 20p CC/CV charging board at 4.2V and ~50mA per cell.

I fire up the CC/CV power supply and set that to 4.2V and 1A

I watch the voltage rise on my Fluke to 4.19 and the amperage will drop to almost nothing when they are done. This can take a day or two.

Sometimes the V will stall at 3. something V and then I know I have what I call a "Vamp" cell. A vampire cell that is pulling all the mA from the others.
I pull all the cells out and check their V. Inadvertently there will be 1 or 2 cells with lower V than the others. I put all the cells that measured good V back in and the meter will show a slow rise again. The LG cell you see there was a "Vamp".I have checked the 20p pack with a thermal camera but so far I have not been able to determine a "Vamp" cell by temp.

The 2V to <3V I mostly treat the same way. IR check first if reasonable and the V is 2.5 and up I will charge them at 300mA on my Zanflairs.
If the V is <2.5V into the 20p charging board they go for a slow rise to 4.2 at 50mA.
3V and up get IR checked again and anything at this point that is over 100mΩ gets binned. 100mΩ is a pretty high criteria so there are very few that don't make that grade. Then I charge them on the TP4056 boards and some of the other of the shelf chargers I have.

Quote:Is what I mentioned before a suitable regimen/system?

I initially did the same thing to "shock the battery into submission" but I have found out that doesn't really do the cell any favours. It's like hitting them with a defibrillator when they aren't dead yet they are just hibernating and need a slow waking up curve. Kinda like a bear coming out of hibernation.
That doesn't mean you will have a good cell or not but I just had 43 UR18650A Sanyo that where ≈1V after the harvest and treated to the slow wakeup curve come back with very good results. Of course the initial IR showed good promise and no heaters.
Gummiadler and Oz18650 like this post
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
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