USB Power Banks Query

MurphyBrix · 26 Dec 2021 at 16:53

Hi all

I bought a duracell 3350 power bank the other month for a lego set I have bought lights for. The lights have a USB only output to power the lights so bought the above power USB bank.

I'm finding that when I connect the lego set to the power bank all the lights come on and then go off barely before 10 seconds.

Ive also received a present which is a statue that changes light of which is also a USB connector. The same issue is happening with that. It stays on for 20 seconds then goes off.

The power bank is fully charged. When I connect both the lights to the mains through a socket and the USB they both stay on.

Does anyone have any experience with USB power banks and what maybe the issue? Would it something to do with the lego and statue drawing so little power it just turns off. I can't see how it is a decent product if that's the case.

Thanks all

Semple · 26 Dec 2021 at 17:11

Normally from my experience it's because it's drawing very little current, it switches off.

MurphyBrix · 26 Dec 2021 at 17:19

Semple said:
Normally from my experience it's because it's drawing very little current, it switches off.

Yeah I had the feeling that may be the case. Anybody with any ideas what else to go for? Something that's a little less powerfull?

d_brennen · 26 Dec 2021 at 17:52

MurphyBrix said:
Yeah I had the feeling that may be the case. Anybody with any ideas what else to go for? Something that's a little less powerfull?

Cheapo poundland type power bank might not have any clever low current cut off? That or add something to the circuit to sink a bit more current

Werewolf · 26 Dec 2021 at 17:53

possibly if you've got a spare usb hub you could try powering both at the same time from the powerbank?

Or different powerbanks may have a lower required "draw" to stay on, iirc you can get some low capacity ones very cheaply.

kona786 · 27 Dec 2021 at 00:12

Yes you need one which handles lower power draw. The smaller anker cylinder ones will do. Also anker E1.

Edit tested E1 and it doesn't work, sorry.

MurphyBrix · 27 Dec 2021 at 13:21

kona786 said:
Yes you need one which handles lower power draw. The smaller anker cylinder ones will do. Also anker e5.

Would the below be one of them:

Anker PowerCore 5000mAh Portable Power Bank

kona786 · 27 Dec 2021 at 16:01

MurphyBrix said:
Would the below be one of them:

Anker PowerCore 5000mAh Portable Power Bank

I can't guarantee that will work you may have to buy and test, return if need be.

You basically need one that says it'll work with low current draw devices in the description.

The one I have tested that works is a Aukey pb n54 which is a small cylinder type one like the Anker you posted.

I thought the Anker E1 worked but it doesn't.

Rroff · 27 Dec 2021 at 22:47

Most of the Anker ones in my experience are designed around charging a phone or lights with >100ma power draw - much below that and they auto power off (some of them IIRC have 40 or 45ma in the manual as the cut-off).

I ended up creating my own with a 18650s, tp4056 charging modules (you can also get prebuilt BMS which will charge multiple li-ion batteries) and a pre-made 5V USB step-up boost board. That setup will have a parasitic draw on the batteries unless you manually switch off when not in use however.

Disco_P · 27 Dec 2021 at 23:10

Look for power banks that advertise trickle charging, otherwise they shutoff at low currents.

Malevolence · 27 Dec 2021 at 23:31

d_brennen said:
Cheapo poundland type power bank might not have any clever low current cut off? That or add something to the circuit to sink a bit more current

Can confirm. Have a couple of the Poundland 2200mAh powerbanks for running some LED lights off and they work fine. Drawing a low current doesn't cause them to switch off.

cheesyboy · 27 Dec 2021 at 23:36

I bought this one for my son for Xmas, and it came with a USB reading light which seems to stay on indefinitely. Either the powerbank has no low power shutoff (can't imagine the light is high-draw) or, otherwise, you can just plug the reading light into the first socket and run your other stuff off the second.

https://www.amazon.co.uk/dp/B07PNL5...abc_G0JXQGBASSJ3N12Q7TWW?_encoding=UTF8&psc=1

Otherwise, get a USB multi adaptor and plug both your Lego stuff and a higher-drawing gadget to it.

kona786 · 28 Dec 2021 at 10:25

MurphyBrix said:
Would the below be one of them:

Anker PowerCore 5000mAh Portable Power Bank

Found one for you

Low-current charging mode
A special mode to charge low-current devices such as bluetooth headphones and fitness trackers .

Aukey Sprint Go Mini 10000mAh PD Power Bank

Competitor so can't link. £15