Simple UPS for IoTaWatt

During a power outage, I only need about 60 seconds of battery run time before the generator turns on. So, I’m thinking about splicing a simple battery backup, inline on the IoTaWatt’s power adapter cable. Will it work? The IoTaWatt’s load current should be less than 1A DC.

Don’t know the details. I guess it depends on the battery you mate it with. Another approach that I think would work, and maybe a little simpler, is to get a rechargeable phone battery pack and run the IoTaWatt from it with the charger connected all the time.

You might want to read up on this site.


He has quite a few articles on UPS for Raspberry PIs. While they do require more power, the other needs are similar. Many of the system’s don’t charge, while providing power. It probably wouldn’t be a problem for your usage for a while, but might be eventually.

The board approach above still needs a battery, enclosure, cables, power supply, and a lot of time. Depending on the entertainment value of the project, it may not be worth it. What about just a small UPS on the 120 volt line?

https://www.amazon.com/AmazonBasics-Standby-UPS-400VA-Outlets/dp/B073Q48Z95/ref=sr_1_1?qid=1560872886&refinements=p_36%3A1253504011&s=pc&sr=1-1

The Amazon Basics UPS is what I had initially planned to do, however it won’t easily fit inside my sprinkler control box. So, because the IoTaWatt only requires 5V DC power, I could use a much smaller DC-only UPS.

I ordered the 10000mAh power pack by Ravpower for $20. Hopefully it can be charging and discharging simultaneously, similar to a UPS. And, hopefully it can handle adverse electrical conditions (high and low voltages), similar to a UPS.

The Ravpower power pack unit fits inside my Orbit sprinkler box, however it does not work like a UPS. When the power is lost, it shuts down. When I press the side button, the unit turns on and powers up the IotaWatt, but then turns off after 10 seconds. It works exactly like any power pack, just not a UPS.

Nice clean installation.:+1:

Just ordered this, as my next attempt with a simple DC UPS. Probably shipping from Manila, delivery in 30 days.

This just arrived today. I have verified that it provides uninterrupted power to the IotaWatt when I cut and restore power to the house. So, it does indeed allow simultaneous charging and discharging of the battery bank, like a UPS. I have no idea what will happen if there is a mains voltage spike, or low voltage. Only time will tell. And, I will probably use a 3A power adapter instead of the IotaWatt power adapter because it will charge the lithium batteries faster.

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Great that you found one that works. I tried the one that Scargill talked about, but it drops the power on transfer, so not good for a UPS.

As far as charging the batteries, unless you REALLY need them charged NOW, slower is better. Fast charging is very damaging to the battery and it can’t take it too many times. When a lithium battery has a fairly low state of charge it is possible to charge it faster. Typically, charging at a rate faster than half of the capacity is considered fast charging, but there are different definitions. It is going to depend on the charge circuit in your supply.

Unless you have frequent power drops close together, slow charging will let your batteries last longer before needing to be replaced.

After looking high & low at charger / power bank products I have bought one of these for my IoTaWatt although I’ve only been testing it on other devices so far.