Custom electronics: Would you guys be interested in a router UPS?


deusExMachina

Member
Disciple
Just asking out of curiosity. I sometimes make small electronic items on the side for personal use. One of these was a small lead-acid 12V UPS as my area had frequent and long power cuts. It was designed with estimated run time of 48 hours (but practically ran for 3 days on testing). The unit is 4 years old and still gives backup beyond 2 days (didn't test till exhaustion recently; it's a bit overengineered).

Would you guys be interested in this? I'd say the advantages are:
1. It's durable (I won't optimize the design to the detriment of service life)
2. It'd be modular and relatively serviceable from use of simple discrete parts. So, there's potential for repair and reuse instead of the consumerism that we're used to these days.
3. If it matters, it's made in India.
 

seshu

*
Adept
it's made in India
does it mean, assembled in India ?

based on my experience with 3 well known brands of router UPS :
some of currently available brands are stated as startup of India BUT their parts are from China.
its difficult to analyze quality of such products - either they work for some time / fail soon ...
 

vink

Member
Disciple
do you a working prototype? post images, test results etc..
and running for 40hrs.. this gonna need big battery i dont think it would fit in any ups enclosure along with ups circuitry itself.
 

deusExMachina

Member
Disciple
@seshu
Nope, designed and built from here. I designed it myself (including the circuit) with all parts sourced locally. The battery is from Exide. The circuit board is hand made in my prototype but if enough people are interested, I'll get it fabricated (again using a local manufacturer).

I know what you mean and sourcing parts from China probably reduces the cost by 10 to 20x.

The UPS that I'm talking about was made for personal use and has been working 24h for about 4 years now without any issues. This is in part due to the battery management/charging, I didn't cut corners with the circuit so it does the full 3-stage charging. From what I've seen, the cheaper designs either have only a CV (constant-voltage) charging for lead-acid or use very poor quality Li-Ion.

I chose a lead-acid based design for the following reasons:

1. It's relatively safer than Li-Ion (no risk of explosion and VRLA lead-acid batteries won't leak, there is very little liquid inside)
2. It's easier to source from good local manufacturers (AMARON Quanta and Exide chloride)
3. Depending on design, these can have long service life (as evident from my own experience). Li-ion batteries will degrade even when not in use. This is especially accelerated when you maintain the charge at ~ 100%
4. Good quality Lead-acid batteries are cheaper than even a poor quality Li-Ion of same capacity.

The only disadvantage is that Lead-acid is bulkier (40 Wh/kg for VRLA vs 150 Wh/kg for Li-Ion)

@vink,
Yup, I have a working prototype that is already in use. I've put some pictures at the end of this post and will post the SoT vs time graphs later to prove how long it lasts as I need to be on station for 3-4 days at a stretch to take measurements (need to travel briefly this week)

It was intended for personal use and does the job but can be improved in terms of size and better wiring. The prototype also has extra features that you guys probably don't need (multiple output voltages and a wifi signal used to indicate a powercut to a script that runs on a PC)

The ~40h run-time is for an average router (max current 500 mA @ 9v) and uses a 14Ah lead acid (Two small UPS batteries). It's about the size of two V-Guard 600VA stabilizers put side by side (but it's not space optimized).

Pictures:
 

skoka123

Well-Known Member
Adept
I would love to have one. My requirement is that it should support 100 W ( 18 W submersible pumps x 5) which will run for 2 mins once every 15 minutes. That would be 192 minutes / day running 100 W of pumps. The longer it runs the better. Ideally a 10 days capacity would be great but I would settle for 4 days. How much would such a setup cost?
 

deusExMachina

Member
Disciple
Could you share some more details of the pumps? What is the nominal voltage that it runs at? How long do you get the power supply for on average?
 

skoka123

Well-Known Member
Adept
Could you share some more details of the pumps? What is the nominal voltage that it runs at? How long do you get the power supply for on average?
It would be something like this submersible pump. They run on regular 220 V. This required to run only when there is a power outage and I am out of town. We generally have no more than a few minutes of power outage once in a while. I also have Inverter. Basically the UPS is required for one of the two following situations.
  1. Out of town and power outage for long duration.
  2. Out of town and the MCB has tripped (happens every once in a while due to RCCB/ELCB during rainy season)
These pumps recirculate water from a reservoir in my dutch bucket Hydroponics setup.
 

deusExMachina

Member
Disciple
@skoka123,
Apologies but I won't be able to make to those requirements at a reasonable cost/time. You need a regular line voltage UPS, the one I was talking about is a low power 12/9 V unit meant for routers and possibly SBCs.

Assuming that you'd be using a line voltage sine wave UPS that uses 12V batteries. You'd need a ~110Ah battery for 4 days of backup and a ~270 Ah battery for 10 days of backup. The usual 600VA UPS unit should be more than adequate for the load.
 

skoka123

Well-Known Member
Adept
@skoka123,
Apologies but I won't be able to make to those requirements at a reasonable cost/time. You need a regular line voltage UPS, the one I was talking about is a low power 12/9 V unit meant for routers and possibly SBCs.

Assuming that you'd be using a line voltage sine wave UPS that uses 12V batteries. You'd need a ~110Ah battery for 4 days of backup and a ~270 Ah battery for 10 days of backup. The usual 600VA UPS unit should be more than adequate for the load.
OK. Thanks.
 

Lozil

Well-Known Member
Adept
Nice Idea, I have been on a constant lookout for something like this, Many times I have sat through and jolted down the requirements, But gave up when it comes to getting my hands dirty. :)

Output Needs:
1. Regulated 12V 2A : 2
2. Regulated 9V 2A : 2
3. Regulated 5V 2A : 1
4. Regulated 5V 2A : 2 USB

The above will be a proper power bank for all the Modem + Router + USB based devices.
The Lead acid is a good solution for cost and ease but the bulk is what makes it boring.

My thoughts always hovered around:
1. Charging circuits : Based on Battery
a. Lead acid charging circuit will be for things which require insane backup​
b. 18650/32650 based ones for the smaller backup requirements which keep the size small.​
2. Charger:
a. Capable of charging battery as well as powering the things connected to it.​
This is a decent thing. It's complex, But will solve many problems. You have any additional thoughts on these? You can DM me.
 

deusExMachina

Member
Disciple
Yeah I know the feeling. Sitting down and actually building stuff almost always takes longer/more effort than I'd anticipate. :)

The design would also changed based on whether you plan to use all those outputs at the same time or if it's a one-or-the-other thing. With the batteries, one thing to keep in mind is that lead-acids will last much longer in these applications because the charge is kept close to 100%. Li-Ion batteries will deteriorate much faster when you do the same thing.

All the best with the build!
 

booo

BA BA BA BABANANA
Veteran
This is a very good idea. why dont you guys team up and come up with something like a home 5g router? it would be a good product including ups, router, pihole, home nas kind of thing and other stuff.
 

deusExMachina

Member
Disciple
@Lozil , I'm planning to build the dc convertors etc using a microcontroller instead of analogue circuitry, just to see if I can (also cause it'd interesting) XD

@booo , Thanks!

Except for the power source, the rest of it would be like assembling a computer. pcengines.ch (Switzerland based) has a bunch of AMD boards with multiple NICs and custom enclosures. It also has PCIe slots to put in a wifi / 5G network card. Finally, on that hardware you can install pfSense which is a much better router OS than openwrt (or any of the proprietary stuff in most consumer routers). pfSense can run snort and pfBlockerNG which has a much better DNS and packet signature based blocking than using just a pihole.

In general, from what I've seen, if there is a mass produced product (especially from China) which fulfills all your needs to a T, it's gonna be cheaper and faster to just use that instead of building an equivalent.

Also from some experience (I didn't pursue this deep enough), it seems to be much more harder to get permissions to sell stuff than it's to build them. If you don't have the right set of licenses, they can shut you down any time. A small company nearby had licenses to manufacture cleaning chemicals and I think IPA. They tried to supply sanitizers when the COVID pandemic started (there was a scarcity at the time) but were quickly shut down due to not having the right set of licenses. There are other requirements too, but don't want to rant about it too much.

In general, it just feels like the systems in place in the country are designed to just discourage you from manufacturing. I just build stuff for myself / friends / family when a better alternative isn't available.
 

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