USB powerbank WITHOUT auto off?

subwoofer

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Hove, UK
And it gets worse:

So, only flat top bare cells fit; forget using any of your other 18650s.
I need to keep running at 0.014A, even at 0.05A this turns off.
I was getting 7.88Wh out of the PB and wondering why - it only uses the right hand slot for the USB output (when viewed with the positive terminal at the top).
You have to take out both cells and swap them to use the full PB capacity. The only thing about this is that you do know when you really get to 50% remaining capacity!
Even on one cell, it is outputting 2A, so that is quite impressive.

Considering I bought it for the low output current, and as a PB, this is a big fail for me.

Can I get a V4.0 from anywhere?
 

lipton5001

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Aug 13, 2018
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Hi guys, first post on here .. hope I don't walk on glass ..

I had a very decent powerbank which always outputted 5V, even with a 50MOhm load (multimeter). It did die out a couple of days ago ... and I've since learned that Samsung has a pretty dodgy record in powerbanks ...

It's this one: https://www.amazon.de/dp/B00S8JYW7M/

Alongside those, the square DIY ones from China also always have the output enabled, however !!! Some of them use chips that don't completely cut the cell off when its voltage drops below the cutoff, and don't have any short circuit protection: so, these ones need thorough testing before being put into service:

1-cell-chinese: https://bit.ly/2nBMPHS
2-cell-chinese: https://bit.ly/2KNZpNo



Hope this helps!


PS: the Anker power banks .. although awesome, cut off at <65mA.
 

angerdan

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Feb 12, 2015
Messages
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Location
Europe
The Just Mobile Gum Pro Battery Pack (4712176184434) did stay owered on until its energy has been drawn.
ebay.co.uk/itm/Just-Mobile-Gum-Pro-Externen-Akku-4-400-mAh/202494217375

Unfortunately it has been discontinued several years ago like many other USB powerbanks with toggle switch.
bhphotovideo.com/c/product/814648-REG/Just_Mobile_PP_08_Gum_Pro_Battery_Pack.html
lygte-info.dk/review/Review%20USB%20battery%20box%204x18650%20%235%20UK.html

Also the precedessor did have an on/off switch.
popgadget.net/2007/08/mobile_gum_for.php

But you can also use some Universal battery chargers to power their USB output with 18650 cells when they are inserted:
lygte-info.dk/review/Review%20Charger%20Folomov%20A1%20UK.html
lygte-info.dk/review/Review%20Charger%20LiitoKala%20Lii-402%20UK.html
lygte-info.dk/review/Review%20Charger%20LiitoKala%20Lii-500%20UK.html
lygte-info.dk/review/Review%20Charger%20Efest%20LUC%20UK.html
lygte-info.dk/review/Review%20Charger%20Xtar%20WP2s%20UK.html
lygte-info.dk/review/Review%20Charger%20Xtar%20VP2%20UK.html
lygte-info.dk/review/Review%20Charger%20EFest%20Xsmart%20UK.html
lygte-info.dk/review/Review%20Charger%20ML-102%20V8.0%202015%20UK.html
google.com/search?q=%22USB+output%22+inurl%3Alygte-info.dk%2Freview%2F&ie=utf-8&oe=utf-8&client=firefox-b

Other solutions:
enerprof.de/shop/batteries/power-banks/tensai-tb-13600-kfz-car-jump-starter-battery-charger-power-bank-48-96wh/
enerprof.de/shop/energy-cases/enerpower-ecd-500-energy-storage-unit-powerbank-500wh-li-ion-generator/
 
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subwoofer

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But you can also use some Universal battery chargers to power their USB output with 18650 cells when they are inserted:

It's funny you should post this as before I saw it, I found an old Xtar 2-cell charger with USB output (WP2 II). The USB output is switched on with a toggle switch. Not sure how efficient the output circuit is, so I'm giving it a runtime test.
 
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Hopkins802

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Jan 11, 2019
Messages
1
I'm hoping the collective can point me in the direction of a USB powerbank which can be permanently turned ON. I have a USB powered clock which on the lowest brightness setting draws so little power, every single USB powerbank I own, automatically shuts off. I have to set it to the highest output for the current draw to be sufficient to keep the powerbank operating.

What I'm looking for is a powerbank that will keep the USB output live regardless of the current draw (like a mains charger would). I realise this means the calls will run down even with no USB load, but need to be able to decide myself when the USB socket is live.

I'd like it to be a reasonable brand (not a no-name hope-for-the-best type product) if possible.

Any ideas?


I have found a simple workaround that should work with just about any USB powerbank that has 2 output ports. It must have 2. I found this tiny USB stick LED light that draws just enough power to keep the power bank on. Then you can plug the device that draws very little power into the other output. Works like a charm! This is the type of thing I’m talking about: Sinywon Flexible Mini USB LED Light Lamp for Laptop, Keyboard, Power Bank, Portable Night Light or Reading Lamp (Pack of 3) https://www.amazon.com/dp/B0191S9I4K/?tag=cpf0b6-20

i just put some electrical tape over the tiny light, and you wouldn’t even know it’s there.
 

Lynx_Arc

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Joined
Oct 1, 2004
Messages
10,691
Location
Tulsa,OK
Hi guys, first post on here .. hope I don't walk on glass ..

I had a very decent powerbank which always outputted 5V, even with a 50MOhm load (multimeter). It did die out a couple of days ago ... and I've since learned that Samsung has a pretty dodgy record in powerbanks ...

It's this one: https://www.amazon.de/dp/B00S8JYW7M/

Alongside those, the square DIY ones from China also always have the output enabled, however !!! Some of them use chips that don't completely cut the cell off when its voltage drops below the cutoff, and don't have any short circuit protection: so, these ones need thorough testing before being put into service:

1-cell-chinese: https://bit.ly/2nBMPHS
2-cell-chinese: https://bit.ly/2KNZpNo



Hope this helps!


PS: the Anker power banks .. although awesome, cut off at <65mA.

I have a few of the rectangular ebay DIY kits and all but the last one I bought would stay on, the last one had a different circuit board in it that wouldn't stay on with a very small load on it. Any power bank with an on switch or a separate LED light mode won't stay on when the load is too small.
I have 3 Anker power banks..... two of them are 3 and 4 cell banks with no LED light and both shut off and the 3rd is a 2 cell one with an LED light and it also won't stay on either. I've bought a lot of different cheap power banks off ebay from china and very few types of them have a circuit that stays on with low loads.

I've also experimented with boost and buck boards plugged into power banks to power 3v and 9v devices to see how they work.
 

angerdan

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Joined
Feb 12, 2015
Messages
284
Location
Europe
I have found a simple workaround that should work with just about any USB powerbank that has 2 output ports. It must have 2.
I found this tiny USB stick LED light that draws just enough power to keep the power bank on.
Then you can plug the device that draws very little power into the other output.
That's an good idea. But it uses more space and blocks the 2nd port. The USB LED stick is from Xioami:
aliexpress.com/item/Original-Xiaomi-USB-Light-Xiaomi-LED-Light-with-USB-for-Power-Bank-comupter-Portable-Shining-Led/32744457452.html

Another option would be an small load (15-30 mA), which can be an cheap USB meter:
ebay.com/itm/USB-2-0-Y-Kabel-A-Stecker-2x-A-Buchse-0-30m-30cm-schwarz-Y-Adapter-Power/173644238419
lygte-info.dk/review/Review%20Xtar%20USB%20current-voltage%20detector%20UK.html

lygte-info.dk/review/USBmeter%20safety%20tester%20J7-t%20UK.html

With an USB Y-cable, you can even charge 2 devices simultaneusly.
ebay.com/itm/USB-2-0-Y-Kabel-A-Stecker-2x-A-Buchse-0-30m-30cm-schwarz-Y-Adapter-Power/173644238419


Any power bank with an on switch or a separate LED light mode won't stay on when the load is too small.
Please avoid full-quotes, this makes the thread less readable.
 
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