Top side, left of double white line on board is the TP4056 SOP-8 package Li Ion charger IC and supporting hardware, right side both top and bottom looks to be the output portion of the PT1301, but it looks like there are 2 (maybe even 3) of them there, but they are using a single inductor
As HKJ said, look at the white silkscreen text on the board. Q1, Q2, Q3, etc is used for simple transistors. Can’t be 3 x PT1301 even if you ignore the single inductor.
Really, U3 appears to be the only PT1301 there.
Yeah, just trying to figure out what those are…from the schematic unless those Q1, Q2, and Q3 are the current boosting transistors
Either way it looks as if this type of setup is going to be much better than the single chips from those other cheapo ones…I was hoping those with the single chip would be good ones…but alas they seem to not work as advertised
Either way, I have 4 of these inbound…going to set them up as semi-permanent portable power rigs [maybe save one for a charger](going to drop a Sanyo laptop pulls I got from 18sixfifty in em, then wrap a single wrap of clear packaging tape to hold it in but still be removable), I don’t trust those other ones I got in, sad because a single chip should have been more efficient or less costly as there would be few associated components to drive the price up…but as we have seen…they aren’t stable enough to be safe
I did order (10) SS24 diodes , some (100) 2.2k ohm 0805 SMD resistors , (10) SMD micro USB plugs from digikey…going to try to mod it to have dual power inputs and 500mA charge current to the battery
Currently by the above 1301 resistor (R2) charge current is right at 1A (per RProg on pin 2 of the TP4056, 1.2K is 1A)
So simply changing this R2 1301 resistor to 2.2k is enough to drop the current to lower value? Or put 1.8k to get something about 0.7A current.
Yes, read the datasheet to find the right resistor (the RProg) level to adjust correct current
2.2K is right around 500mA
And wouldn’t you know it…after I ordered the micro USB connectors and diode, they ship me Version 6 which eliminate the Mini USB connector going straight to a Micro USB…yay
Thanks, I also read that the termination current will be lower, but I don’t understand if it’s good or bad:/
Does the LED shows the capacity state when you put the battery inside, or only during the charging?
Only when the battery is in…red charging, green when charged…under the negative connector is a blue LED on the board, when it is “outcharging” the blue led glows alot brighter and you can see it shining thru the semi clear plastic body
Terminating current is when the “charging” IC detects the battery is full, at a full 1A charge rate it’s 60mA, at lower its maybe 40~mA…
Depends, you get a slight higher charge (This is NOT over charge), but the charge time is longer.
The exception is very old cells that might have problems terminating, if the current gets to low.
Thanks for the excellent review. I ordered one late last week (v5.)
I really like the graphs so I can see whats going on.
I changed out the RProg on my Miller ML-102 Version 6’s (the 1301 resistor next to the TP4056 chip)…today I changed out the resistors on a fellow members small TP4056 charging modules. Output with a 2.2k (0805 sized resistor) resistor was .53A and .48A respectively. Yes it will take longer to charge…but puts less stress on batteries while charging
Nice mod! One could put a little slider switch, to choose different charging currents.
Just thought I would mention this - I picked up an iPad Air recently and the ML-102 V5 actually does charge it - you would need a large capacity cell, or a few smaller ones, to get much juice into it, but the little guy does charge it with enough current to avoid the “Not Charging” message. 
I will probably do a bit more testing to get a better idea of how much can be expected from the 2600mah cell I keep in the ML102 I carry with me.
Topped off from 92% to 100% so far.
UPDATE:
It looks like I can get about 14% (79–93) on the iPad Air from one cell (I believe it measured somewhere in the 2200-2400 mah range when charging, IIRC)…
You can charge a 5VDC device with a 3.7VDC battery ?
The ML-102 has a boost circuit. It provides a usb port with 5v.
ML 102 V5 heavy use update, it won’t always terminate, about 50% of the time the light stays red, the battery is at full voltage (it charges to 4.11V and after 4-6 hours the battery is at 4.10-4.12V). The battery is not warm or hot, but the charger says its still charging.
I have used it for maybe 200-300 recharges since i got it.
Why they didn’t add a charge level indicator on it ? It’s not like they were going out of space.
It is not a a CC/CV charger, but is that really better than something like
http://www.fasttech.com/products/0/10004229/1443600-sc-0217-1-0a-diy-mobile-power-bank-pcb-board
that gives the same + charge level (we would have to replace the pcb) ?
You could just add a little voltmeter:
Or, if you want to make it really interesting…
Since this thread hasn’t been updated for a while I will report some numbers…
Ordered 16/9/14 and received V7.1.
-Same terminals as V5.0
-With nothing plugged in, just the battery, blue led stays on dimly and standby current is 0.2mA.
-Auto turn-on with the slightest load, my USB power meter turned USB output on.
-Doesn’t turn off USB output as long as there is a load.
-Charging a power bank, draw is 1.8A, tested for 3 minutes and didn’t drop. Gets warm.
-Charging an iPhone 6, draw is 0.95A. This is weird because the iPhone 6 takes up to 1.3A from a power bank or regular charger. Apple 1A coded? Gets a little warm.
-Using a topped NCR18650B, it can fully charge an empty iPhone 6 (1810mAh battery) in about 2 hours.
-Efficiency of the ML-102:
IN: 3.93V 1.50A = 5.85W
OUT: 5.05V 0.98A = 4.95W
About 85% efficiency, not bad.
-Battery reads 3.43V at the end. I think there is some juice left in the battery, so I would assume an overall efficiency of 60%. Not really sure why, because the iPhone is efficient, doesn’t get hot at all when charging. I believe efficiency of the ML-102 drops when the battery voltage drops. Will test again with a mid empty cell.
Because I only have one, my testing is slow. Tomorrow I will do charging and monitor the termination, I expect it to be in the 4.1-4.2V range.
This is the led that stays on when you put in a battery, hardly visible with the case on.
Awesome…I have V6.0, they did a massive re-do when they hit 7 I believe
Excellent post Will!
My V7.0 has a TP4056, this one has a buck circuit from what it see