Review: USB battery box 4x18650 Coolook PB-2000

This 2 x 18650 box can do 2 amps. Ebay $8.29. Also the 4x18650 Huamen/Evertones ET-406. Neither are ideal for charging the 18650s. With luck there might be room to cram a tp4065 charger board in the 2 x 18650 box under its pcb.

it’s not that your Coollook can’t put out 2.1A on one of the ports…its the device charging needs to see the apple charge signature from the charging device…if it doesn’t see it, it will automatically restrict it’s maximum charging capability…

You need to setup a charge controller or build a dedicated charging port for your device

http://oshpark.com/shared_projects/NIDe7kjj

The chip mounted on this lets the device plugged into it know it can deliver the proper current

Actually to fix your problem…you need a USB wrapper…a device to get between your charging device and charger and then tell it thru resistor bridges and whatnot what juice to pull

hmmm…wonder how accurate that is

Alot of times I see these chargers say they have that coding but looking thru a charge doctor it just won’t pull more than 1A, then opening it up see the pads for the resistors connected to the center data pins and nothing being there…save that .0001 cents by not putting those resistors in

The one I tested used that coding.

The new verson 7 miller ML-102 might be able to do 2.1A.

I managed to buy some PB-2000 off the bay, togheter with the newer Aili Power box. The PB-2000 have a superior electronics, but I like the Aili for their look.
The PB-2000 is the best power bank I have seen around; it doesn’t use electrolytic capacitors, and have an output LC noise filter only seen in high-end power supply design. Also, the efficiency is the highest in this class of equipment.
While conducting some current measurement, I did a mistake. I connectected the multimeter, set on the 10 Amp range, in parallelel with the batteries. I have a multimeter with a fuse on the 10 Amp range, and initially I tought that the multimeter fuse was the only one casualty conseguent to my mistake. The batteries, even if unprotected, had their own PTC device, they were undamaged. But.
I tried to power on the PB-2000, but the green LEDs behaved erratically. Connected a light bulb, but it lighted dimly; measured the output, it was 3.2 Volt. All in all, the circuit was not stepping up the battery voltage anymore. After some trouble shooting, I found the switcher MOSFET (the only visible big transistor) had the gate shorted with the source, and the driver chip (a tiny six pin SMD component on the other side of the PCB) had the output open. After a tracking analisys, I realised that, by shorting the batteries a capacitor had discharged, via the ESD protection diode in the MOSFET, thru the driver; destroying the driver IC itself and the power transistor. So, my advice, do not SHORT the input!
Aside this fault of mine, the PB-2000 remains the best DIY power bank available at the moment, and I would like to thank HKJ for the insightful review.
Anthony

Mine doesn’t seem to be coded for apple as it won’t give more than 1A to my ipad.
OK, too bad, but the thing that gets me is that if I charge it up full and leave it for a week or two, the cells seem to self discharge down to the cut off. These are brand new Panasonic 3400 cells, and there is nothing wrong with them. Why is the Coolook draining them when it is turned off and not being used.

For what it is worth, I’ve noticed that knock-off lightning cables don’t get things right for delivering full current to apple devices with powerbanks that work fine with genuine cables.

Question going back to the original review at the top:

It says: “When using multiple batteries, remember that they must have the same voltage when put into the box, easiest way to do this is to charge all batteries first.”

No problem with that, I can charge the batteries in an Intellicharger I4 independently.

But — after they’ve been run down a bit — trust that the batteries now are at the same voltage when partly discharged, and use the charging port?

Has anyone checked voltage on cells after the batterybank has been used, to see if they come down at the same voltage?

Look at this photo:

The two metal rails connects the batteries in parallel, it is simply not possible for the batteries to have different voltage.

Thank you for another great review. I’m going to grab one or two of these.

Could be a bad cell…a bad cell in the “battery” (multiple cells) can draw all of them down

Would you be able to see if this battery box will accept charging voltage other then 5v? Im looking to have it attach directly to a 10w solar pannel and not go through the solar pannel usb controller for better efficiancy

Sorry, but no.

The box has two inductors, this probably means that the charge controller is using a switching regulator, i.e. it might work with higher input voltage.

Seems like a good power bank but I’d like to add one thing.

As HKJ stated there are no directions at all included including no indication on how to open the darn thing without breaking it. Slide the lower cover straight back (away from the USB outlets) until it stops, about 8mm then lift.

Hopefully this will help.

I had the same trouble with the sliding cover on the Coolook, but once I figured out the direction to push it got easier.
Also, buffing the edges of the sliding parts a bit with coarse cloth seened to take off some rough edges, plus adding a bit of grease (well … nose oil, actually, nature’s lubricant …)

Loogies work wonders also. :Sp

> if I charge it up full and leave it for a week or two, the cells seem to self discharge down to the cut off….
> Why is the Coolook draining them when it is turned off and not being used.

How are you testing that? I have a couple of the Coolooks, loaded with eight Samsung ICR18650 26C cells (salvage from a Mac battery pack that had quit working)

(the 10th cell in that pack failed to take a charge, when I tested each of the cells original; so I’ve got one spare that seemed as good as the other eight).
So I put four in each Coolook and one to spare.

So they’d been sitting for a few weeks in the two Coolooks
and using a USB Doctor plug, just today, one of the Coolooks showed 5.2v and the other 3.6v.

So I’m suspecting I’ve got one or more bad cells
— I’m charging all eight cells tonight in my Intellicharger I4, then will see if I can determine any difference among them with a Liitokala charger.
Then back in the box for a few weeks and recheck.

Something funny, anyhow.

For HKJ, if you have advice on how to test individual cells, or a pointer to such, I’d be glad to be educated about doing that the best way.

Any thought about replacing the springs on the Coolook?

I — uh — had all the cells out of one, and put the first two cells back in with one reversed — WRONG
Yanked the cells out again right away.

Barely in time.

Both springs had collapsed and changed color from overheating (and the springs were HOT)

I stretched them out again but they’ve lost some temper.

It doesn’t appear my screwup affected the electronics, I just — “just” — created a short circuit briefly.
Not enough to drop the measured voltage on the cells. Or catch the house on fire or poison myself or anything.

So I’m mentioning this as a caution — flat top cells salvaged from computer packs without the little bump on the positive end need to be looked at carefully twice.

I’m not sure if I need to replace those springs I overheated; if so I wonder if something other than stock chrome plated steel springs would be a good idea in this use.