Let's design our own UPS

Magnum said:
How the UPS coming on guys?
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I gave up after finding something suitable for my needs on Takealot. I'm an electronic engineer so you'd think I should be able to design something, but between my actual job and making sure my family is cared for, an extra design project of this magnitude on the side isn't trivial.
 
Although that being said, I have noticed that 19V output UPSes are quite difficult to find. I scored one of these:

Takealot.com: Online Shopping | SA's leading online store

South Africa's leading online store. Fast, reliable delivery to your door. Many ways to pay. Shop anything you can imagine: TVs, laptops, cellphones, kitchen appliances, toys, books, beauty & more. Shop the mobile app anytime, anywhere.
www.takealot.com www.takealot.com
but I see they're "out of stock" now and have been for a while. Just about everything does 12V.

I love Asus routers but damn they use an awkward voltage. So maybe I might have to start taking this project more seriously at some stage.
 
Magnum said:
How the UPS coming on guys?
Click to expand...
Designed and built one over a year ago haha, been smooth sailing since besides the BMS actually kicking in and having to spark it to start charging again.
 
newby_investor said:
Although that being said, I have noticed that 19V output UPSes are quite difficult to find. I scored one of these:

Takealot.com: Online Shopping | SA's leading online store

South Africa's leading online store. Fast, reliable delivery to your door. Many ways to pay. Shop anything you can imagine: TVs, laptops, cellphones, kitchen appliances, toys, books, beauty & more. Shop the mobile app anytime, anywhere.
www.takealot.com www.takealot.com
but I see they're "out of stock" now and have been for a while. Just about everything does 12V.

I love Asus routers but damn they use an awkward voltage. So maybe I might have to start taking this project more seriously at some stage.
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Once you leave Asus you will never look back do itttttt
 
Recently passed 1000 days uptime on my Pi powered by homebrew DC-DC UPS. Also does ONT and router/AP. Total is about 15 W.

This is an old 50 Ah car battery which was "dead" (for car purposes I guess) about 4 years ago, and must be going on 10 years old. Can still do more than 12 hours with this load. Definitely seems the trick with lead acid is massively oversizing it.

ups.png

Next up I need to find a solution for my gate, which doesn't recharge fast enough. I'm going to run into the same problem with the UPS past stage 6.

gate.png
 
Solarion said:
I'm not sure if this is the right place to ask this. I'm looking for something that can power a PC with a 650w power supply, a screen, modem and 1 lamp for 2 hours. Something like this, compact and mobile.

za.ecoflow.com

EcoFlow RIVER Portable Power Station | EcoFlow South Africa

Buy EcoFlow RIVER Portable Power Station at the lowest price in South Africa. Check reviews and buy EcoFlow RIVER Portable Power Station today.
za.ecoflow.com za.ecoflow.com

This the right thread?
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Get a plug that will tell you how much power you use in the time that you want to run from batteries. This will also tell you the peak power requirement: https://www.geewiz.co.za/gadgets/43...10&sfdr_hash=105bbe2e1143851ca6a6836c4c2b3300

When you have this you can look for something that will have the adequate Watt hours (Wh) of power...
(300w for 2 hours = 600Wh for example )
It is always good to over-speck batteries. You don't want to drain batteries dead and inverters are not 100% efficient and there will always be losses.
 
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Solarion said:
I'm not sure if this is the right place to ask this. I'm looking for something that can power a PC with a 650w power supply, a screen, modem and 1 lamp for 2 hours. Something like this, compact and mobile.

za.ecoflow.com

EcoFlow RIVER Portable Power Station | EcoFlow South Africa

Buy EcoFlow RIVER Portable Power Station at the lowest price in South Africa. Check reviews and buy EcoFlow RIVER Portable Power Station today.
za.ecoflow.com za.ecoflow.com

This the right thread?
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Those do look nice design wise and portability, however not sure about the specs. I don't like the only 500 battery cycles and how will you replace the battery? . Won't our current loadshedding kill it within 2 years. Would be nice to see an in depth review on these.

I know Something like this will work and then select the lithium battery option (3000+ cycles) https://www.geewiz.co.za/mecer-long...tery-life-kit-720w-150-200-cycles.html?aff=70

You do not want a high cycle battery, at minimum a deep cycle lead acid, but try go for Lithium.

Mecer 2400VA Inverter (Community Support)

This Thread is for the Mecer Inverter only. My personal opinion on the unit: Seeing that there are lots of question and in lots if threads, here is my review/input on the Mecer Inverter. Instead of reposting I'll just reference here. I'll add more info soon. This should give you an idea what...
mybroadband.co.za mybroadband.co.za
 
maumau said:
Don't aks me, I just saw the ad :unsure:
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No problem, it's actually more general. See lots of adverts for it, I am surprised we haven't seen a thread and user based feedback yet. They do look nice on the outside and practical to move.

Would like to know:

- how well does it work for an always on UPS, compared to an inverter setup like an Axpert or Mecer
- how noisy is it. Mecer and Axpert type is loud.
- how long will the battery last and why only 500 cycles if it is lithium. I would think at minimum 2000 cycles
- what protection is there for the batteries cut off or is that why they say 500 cycles running them flat
- how easily can they be replaced and what are the costs
- how long can you run it at its full wattage etc.
 
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RedViking said:
No problem, it's actually more general. See lots of adverts for it, I am surprised we haven't seen a thread and user based feedback yet. They do look nice on the outside and practical to move.

Would like to know:

- how well does it work for an always on UPS, compared to an inverter setup like an Axpert or Mecer
- how noisy is it. Mecer and Axpert type is loud.
- how long will the battery last and why only 500 cycles if it is lithium. I would think at minimum 2000 cycles
- what protection is there for the batteries cut off or is that why they say 500 cycles running them flat
- how easily can they be replaced and what are the costs
- how long can you run it at its full wattage etc.
Click to expand...

Absolutely, thanks for asking these important questions.

I'm thinking of buying one myself so look forward to the answers.
 
newby_investor said:
I gave up after finding something suitable for my needs on Takealot. I'm an electronic engineer so you'd think I should be able to design something, but between my actual job and making sure my family is cared for, an extra design project of this magnitude on the side isn't trivial.
Click to expand...
Meh, there is plenty of advice to get out of a long term relationship and how to treat "a female" around here so you won't be lonely .

Follow that and have more time then lol
 
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Reactions: rh1
RedViking said:
No problem, it's actually more general. See lots of adverts for it, I am surprised we haven't seen a thread and user based feedback yet. They do look nice on the outside and practical to move.

Would like to know:

- how well does it work for an always on UPS, compared to an inverter setup like an Axpert or Mecer
- how noisy is it. Mecer and Axpert type is loud.
- how long will the battery last and why only 500 cycles if it is lithium. I would think at minimum 2000 cycles
- what protection is there for the batteries cut off or is that why they say 500 cycles running them flat
- how easily can they be replaced and what are the costs
- how long can you run it at its full wattage etc.
Click to expand...
fwiw I think 500 cycles is standard for certain types of Li chemistry. BUT that does mean full to empty or empty to full. So if, for example, you charge between 30% and 80%, that would only count as half a cycle.
 
Hi guys, I finally made the swop from gel to lifepo4. I only use the inverter for TV and a laptop. With my killawatt meter I use between 60 and 80watt so my power need is not that high :) I orderd the victron 12/250 inverter, the 12/7 blue smart charger(victron) and a 50ah vestwoods lifepo4 battery. I do have an outomatic inverter transfer switch from my previous system that ill be using. R9100. What do you guys think?
 
Lately I was thinking what it would take to build a pure sine wave inverter from scratch... should be cheaper than what is on the market?
 
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