I exploring the option of using a powerbank as a UPS for a router that is confined to a small lock box. Every time the power goes out, the IP changes and it losses connection. The router takes a 5v/3A power adapter. If I could find a powerbank that has passthrough, I am wondering if I could keep it connected to a 1A charger and have it output 5V to a barrel plug for the router (this part might have to be a mod).
Any ideas on this concept?
I am not sure if I can get a ups that is small enough to fit in the lock box. However, I need to make sure whatever I come up with is safe.
UPSs don’t have actual (literal) pass-though, instead the output regulating circuit is ON all the time while the charge regulator supplies the battery with a float voltage, so when the power goes out current flow is uninterrupted.
There are very few powerbank with “pass-through”, and for this application I can only comment on the Miller ML-202. It has regulated 5V output and a separated input charge module that can take up to ~20V. However I’m not sure if the output part can supply constant 5V3A without overheating.
You may also want to go the DIY route:
- 18650 parallel pack : 2, 4 or whatever number of cells you wish to use. LifePo4 is a safer chemistry.
- AC-DC adapter : for the CC/CV buck converter. At least 12V 3A.
- CC/CV step down buck converter : keeps the battery at a certain charge state, but make sure to set it on constant voltage and lower than 4.2V to avoid cell overcharging. Current must be higher than your device requirement.
CC/CV step up boost converter : this will convert your 3.7V into 5V, set it into constant voltage mode by adjusting the current range beyond the device draw.
It might sound complicated but it is actually fairly simple, this would be like some sorts of poorman’s solar backup system, but instead of solar input you use normal DC input. The CC/CV boost/buck boards are under $10 each, batteries about $5 each, and any cheap laptop charger should do the job here.
I have experimented with the Miller ML-202 recently, and it does work well except for one condition… when the batteries are depleted and the unit cuts off (as a battery protection measure), then it wont cut back on when line power returns without user intervention. In my case I had to pull both batteries and line power to reset the charger. Then the batteries will charge back up so long as the load doesn’t trigger the battery protection again…
The newest xiaomi QC power bank has this function…and your plan seems okay but the problem might be the 3A, if the router really needs 3A for a longer period this is probably to much for the most pass through power banks…
HKJ has some reviews and since a while he marks the item as UPS if it has this function.
I must not have notifications set up properly, I didn’t know anyone had replied. Thanks for all of the responses. I definitely need a hands off solution, so I am glad to know about details like the battery protection cutoff that netprince mentioned.
I agree that 3A is a pretty high requirement. Since this group of experts doesn’t know of an off the shelf solution, I think I am better off buying the smallest UPS I can find.
The first thing you can do, today, is to use a fixed IP address for your Router (and any other infrastructure equipment you have).
If you can’t do that, see if you can get some sensible IP address Reserved in the DHCP Server for your Router (by MAC address, but you can see that from the DHCP server while everything’s working).
Then you’ll only have to deal with the howling silence coming from whatever’s on the other side of that Router when it’s down.
Then you can take your time digging up a wee UPS. Like this maybe
I wish I could use a static IP but that is cost prohibitive. Both devices behind the router are static.
Nice find on the APC 70. I found this 400w that might fit. It is cheaper and offers more run time. I will have to get the dimensions of the enclosure itself to see if there will be room for either.
The brick wall and the metal door are both tough. Wifi is used to get the new public IP so Wifi is enabled. It’s range is only actually good directly in front of the door.
Worse, this is on Frontier who bought out Verizon in this service area. They have done such a bad job with the transition that they are getting sued for it. This router doesn’t update the DDNS address I got from dyndns after a power outage. I don’t have a Windows/Mac/Linux device that can run their DDNS update client. A UPS seems to be the better choice over configuring a RPi to run the update client.
Why not just pay the good folks over at DigitalOcean $5/mo for your very own VPS server? Then you don’t need all that… stuff.
They bill by the hour, so you can leave anytime.
Yeah, the Router would have to support it, and I can’t really tell from your picture which Router you had, so I took a shot.
Have you monitored your mains supply to see how long & how frequently it goes down? If it’s not a big problem, maybe this Portable Phone Charger could be adapted to plug in to your Router.
EDIT: Knowing how much your Router actually draws (the wall wart spec is for extreme conditions) would help compute the capacity you’d need for the expected downtime.
The only reason I can think of for DNS mattering is you must be running a home server. I was suggesting running it ‘in the cloud’ instead. Then all you need is basic internet access like the rest of their customers, so DNS and DDNS doesn’t matter.
“The cloud” is just a euphemism for “The Internet”. He stated he has deployed 2 cameras & that’s all that’s behind the quite ignorant Router. It wakes up lost in the woods & no way for anyone in the cloud to know how to find it until it reaches out, which it probably cannot be made to do.
The cameras are, essentially, Servers, but they’re quite ignorant too, in that all they can do is be HTTP Servers & don’t know how to detect their WAN IP address & send an update to DDNS.
However, comma, if they could be configured to push their content, the IP address wouldn’t matter… ?? Or have either the cameras or the router save their log files on your end, which would show up when a power-cycle triggers their logging to start… Or have either of them “simply” (yeah, right) try to connect to your end via some weird port, which you could set a Firewall Rule on your end to raise an alarm on access to that port…
Grasping at straws here. What’s your longest Outage to date?
