Has been almost 2 weeks with the RavPower connected. Have disconnected the power bank input and the hub didn’t reboot. This appears to work. We haven’t lost power in years, so real world testing most likely won’t happen.
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Interesting... but not quite sub $10.
Does the RAVPower information suggest charging and discharging at the same time is supported?
I guess I'm wondering if there isn't a power glitch when loosing input power or there is a small glitch that doesn't reset the Hub.
We lose power so often I’ve ordered a Tesla power wall and all my comms gear and IT gear are on ups power.
It has been proven the sub $10.00 solution does not work.
Check an earlier post from me where I had a USB tester in series with the hub. I removed the input voltage from the power bank while graphing the output. The output didn’t change a bit when the input was removed
Actually that is not 100% correct. I believe there are two <$10 solutions, one works and the other doesn't.
I would have liked to test the other board but never got the time.
The below is the one that works. It's been in service since August 2020 with out a kickup.
Full disclosure, I did choose to solder wires instead of using the original connectors but that was a personal choice not a functional requirement.
Here is a current link to the board I have found to be fully functional as a UPS
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Mine both work perfectly! You just need the correct parts. I even documented the end to end solution to make it easier for folks.
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Mine also works fine.
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Duly noted. Thanks for teaching this old man.
This feature is called "pass through charging" that is, it allows charging and recharging at the same time.
I you search through the powerbank database in:
and look for models with that feature, you will find a number of units have the feature.
Pass through charging alone won’t work for a hub.
I have a power bank that will power during charging but when the power is applied or removed from the bank there is an interruption to the hub long enough to reboot the hub. See the topic Hub UPS for my experience
I just received my board from that link, and it looks like they have changed them. The board looks slightly different, and the output turns off for about .75 seconds when disconnecting input power. It then turns back on and runs on battery. Pass through charging works. This won't work as needed, however.
Just wanted to let others know.
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There are at least two different boards I am aware of. I've not used the one you posted so I can't comment but I know the board in my post #277 works fine. I've looked at each IC and the circuit and understand why there is not glitch when power switches from/to battery.
One issue I've had is at a little over a year, the 18650 went belly up. Open circuit no energy.
Looking into it the life of the lithium's is reduced when"
- you charge continuously above 80%. So this board running at 4.2 volts 100% of the time is not the best case.
- The batteries like to be "worked" sitting at 100% and seldom if ever being discharged even a little is not the best.
For now I'm just going to change batteries at 10 months or so. I'm looking into a solution but it's not a high priority.
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The one i bought was from the link in your post. That's why I was posting as a public service announcement to let others know that the vendor has changed what they are shipping. Even the picture in the store link is different than what they sent. Maybe i will send them a message and see if they still have any of the other ones as they are pictured.
I found the version I had became hard to find. I think when whomever makes these boards makes a "LOT" of boards. The seem to be selling from numerous ebay vendors. And when there are all sold... their gone for good.
However I was recently looking for something and came across these boards on a vendor site I felt could deliver them. However I don't recall where.
I did find this link on Amazon It's still only going by the provided photo but at least you can return it to Amazon. Or you could ask the vendor before purchase.
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I ordered the one in that amazon link, and it does work as needed. Thanks.
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Found this on Amazon looking for a longer run time. Cost is about 20USD. It takes 2 x 18650 cells and appears well made. It has a much higher charge rate and I observed output up to 2 amps(not that we need that) and it charges quickly compared to the single cell version. I'll be testing it and posting more results.
https://smile.amazon.com/gp/product/B09QKJTQKJ/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
Okay, so I let a C7 hub run till the batteries were dead, it was 24 hours run time. It seems to me, based on casual testing, that the circuitry in this 2 cell version is less efficient than the single cell version, which ran for over 13 hours IIRC
Rookie mistake, I used 2 high power Samsung 18650's(3000mAh) versus the 3500mAh panasonic cells in the single cell version. If I can find 2 newer panasonic cells I'll retest with those.
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hey @lewis.heidrick any chance you can make one of your cases that could have this built inside it?
edit: maybe scratch that. so much conflicting info here, and for solutions that to seem to work, the pricing is higher than a pre-built ups.
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Has anyone looked at this? Wondering if this is worth pursuing. I'm sure someone could do a 3d printed enclosure easily enough
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That looks really good, I’ll take a look at the design and look into the BOM costs tomorrow.
If it can be built for a reasonable price, I’ll make them available on my Tindie store.
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Looks nice. For 20 USD the Pi Power seems to be an economical solution, although I like the design & battery handling of the device you linked.
I'm still using 3 of my intial sub 10$ solution. The power has only blipped once since I implemented the UPS, and the board kept things running easily. I've had to swap out 2 of the 18650's as after being charged for 3 years, they're worn out.
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