Laowa 25mm ring light not working on power bank

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Dieter
Posts: 12
Joined: Sun Nov 08, 2020 7:59 pm
Location: London, UK

Laowa 25mm ring light not working on power bank

Post by Dieter »

Hello macro friends,

my ring light should work on a 5000 mAhs power bank (description from UK big dealer) but it does not work on my even 5200 mAhs Hähnel DuoPal Extra. Original cable for the ring light used. I also tried other cables - no result.

It works only with the cable from my mobile phone carger, which is connected to the mains. So, I'm not able to use it in the field - but that's what I desperately want to get my hands on.

Any idea or help, please?

Dieter, London

Chris S.
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Re: Laowa 25mm ring light not working on power bank

Post by Chris S. »

Dieter,

Just a guess, here—I have not used this ring light.

Before we go further, you’ve made certain your power banks are fully charged, right? I'm sure you have. :D

----

If so, my guess is that neither of your power banks has sufficient wattage to power your ring light. The numbers you’ve given—5000mAh (milliamp-hours) for one, 5200mAh for the other—tell us only the storage capacity of these power banks. They do not tell us the discharge characteristics of the power banks--how quickly or forcefully the power banks discharge into a connected device.

My bet is that you need a power bank that delivers electricity more expeditiously into a connected device. A measurement for this is wattage.

If you check the output wattage on your power banks (which don't work with your ring light), I suspect it will be lower than the output wattage on your mains power supply (that does work with your ring light). What I think you need is a power bank capable of outputting a higher wattage.

One known-good solution has been documented by photography blogger Walter Sanford, who makes this ring light work with an Anker PowerCore+ 26800mAh PD 45W power bank.

I’ve oversimplified a bit, and purists may cringe at reading this post. But you indicated in another thread that you are not an fan of heavy technical details. If you do happen to desire additional discourse on electrical theory or the behavior of power banks, let us know!

Cheers,

--Chris S.

MarkSturtevant
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Re: Laowa 25mm ring light not working on power bank

Post by MarkSturtevant »

I am surprised that the light needs more power than is delivered from a common kind of power bank.
I have a few of these batteries, and generally there is a small button on them. You can plug them into led lights (I use USB led lights), and ... nothing. But push the tiny button on the battery, and bingo, the leds light up.
Mark Sturtevant
Dept. of Still Waters

Chris S.
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Re: Laowa 25mm ring light not working on power bank

Post by Chris S. »

MarkSturtevant wrote:
Wed Sep 06, 2023 10:00 pm

I have a few of these batteries, and generally there is a small button on them. You can plug them into led lights (I use USB led lights), and ... nothing. But push the tiny button on the battery, and bingo, the leds light up.
Thanks, Mark! And you may be right. I have no power banks similar to yours or Dieter's--the closest item I have is a Goal Zero Sherpa 100AC that I use when camping, with a pair of Goal Zero Nomad 20 portable solar panels. My Goal Zero Sherpa has no "tiny button" as you describe, but it is intended for a different use (charging devices when the sun is not shining).

If Dieter's power banks have a small button similar to yours, and if it works for him--great!! I'm just trying to help, with my limited knowledge.

So Dieter--is there a "small button" you can press on your power banks?

Cheers,

--Chris

MarkSturtevant
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Re: Laowa 25mm ring light not working on power bank

Post by MarkSturtevant »

From this web site: https://www.photospecialist.com/hahnel- ... ra-charger I believe I see a little round button on the battery, and this is needed to actually deliver power to another device. From the link, I read that there are two ways to push the button, depending on what it is used for. I don't know why that should be different.
It might depend also on the kind of usb cable that is used. Maybe they have a chip that controls whether power gets through?

Anyway , at the link I see a way to ask them questions. You can ask them whether this can be used for LED lights. I don't know why it would not work, except for that button.

You mentioned you can use the lights thru your cell phone charger. Why not just use that?
Mark Sturtevant
Dept. of Still Waters

Dieter
Posts: 12
Joined: Sun Nov 08, 2020 7:59 pm
Location: London, UK

Re: Laowa 25mm ring light not working on power bank

Post by Dieter »

hello Mark and all the other "good ghosts",
thanks for trying to help, but ...
... how to get the mains with the mobile charger out in the park to take shots with the ring light? LOL !

Also, I used quiet a variety of cabels - no positiv result.
And yes, the power bank has this "little button" to jump into action, but it makes no difference - and trying different ways of pushing that button does nothing different.
My "un-technical" assumption is, that the Hähnel power bank is simply to weak to make the ring flash working.
I will try to find a more powerful one (and this one will end up at ebay). Possibly I should ask those YouTube guys who use the Laowa ring flash in the field.

Dieter, London

Chris S.
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Re: Laowa 25mm ring light not working on power bank

Post by Chris S. »

Dieter wrote:
Sat Sep 09, 2023 2:53 am
Possibly I should ask those YouTube guys who use the Laowa ring flash in the field.
Chris S. wrote:
Wed Sep 06, 2023 9:21 pm
One known-good solution has been documented by photography blogger Walter Sanford, who makes this ring light work with an Anker PowerCore+ 26800mAh PD 45W power bank.
Why not just purchase a known-good solution that has been documented by a photographer who uses the Laowa ring light in the field?

--Chris S.

Dieter
Posts: 12
Joined: Sun Nov 08, 2020 7:59 pm
Location: London, UK

Re: Laowa 25mm ring light not working on power bank

Post by Dieter »

reply to Chris:
my research and than the final option is to buy another set, ment to work together. As a pensioner I live only on a very narrow budged which leaves me not much room for fancy financially escapades.
Also I will try to build myself around my flash some kind of diffuser (and bringing the light to the front end of the lens) to overcome the technical problems with the Laowa. This one can work in studio setup where the mains is available.
I had the Hähnel and the ring flash already sitting here for years, but could not do anything photography-wise because I was very ill and occupied by other live-keeping things. But with a great victory over the big "C" my life started again and I jumped recently back into my hobby.
Thanks guys for all your advise,
Dieter London

macrolophus
Posts: 15
Joined: Tue Mar 07, 2023 11:10 am

Re: Laowa 25mm ring light not working on power bank

Post by macrolophus »

There might be some quality problems with this LED ring light:
https://www.amazon.com/Venus-Laowa-Fron ... B07NKD75WB
(But I really don't know, I never tried it.)

It's not so plausible that the power bank might be too weak. No indication of special requirements in this statement from from Laowa:
"Simply connect the LED ring light to a portable charger with the included cable to start using."
https://www.laowalenses.ca/product/25mm ... ing-light/

Dieter
Posts: 12
Joined: Sun Nov 08, 2020 7:59 pm
Location: London, UK

Re: Laowa 25mm ring light not working on power bank

Post by Dieter »

to all who tried to help:
Laowa replied with mentioning that the power bank should have a min. of 30 Watt power output !
My Hähnel power bank has only 12.5 Watt, therefor it was simply too weak to work on the ring light - but good enough to recharge or power something else.
This is a decent one that I will consider: Anker Nano Power Bank (30W, Built-In USB-C Cable).
For now the problem is solved.
Thanks again to all that tried to help me.
Dieter, London

macrolophus
Posts: 15
Joined: Tue Mar 07, 2023 11:10 am

Re: Laowa 25mm ring light not working on power bank

Post by macrolophus »

Good to see that you sort things out!
30W is quite a huge amount of power. It's what I use to light up my medium sized kitchen. At about 1m distance from the LEDs it allows me to exposure 1/30 F2.8 at ISO 100 (of course not useful for extreme macro work). But the Laowa LEDs sits just 5cm from the subject. I wonder if the Laowa LED is a bit of overkill for a mounted camera setup and static subjects. If used hand-held and/or for non-static subjects, I guess a tiny custom flash with LED modeling light might be better to avoid motion blur (and not scare away small insects).

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