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Regular readers of this blog know I’m a huge proponent of Battery Backup devices.
Truth be told, they are absolutely essential if you live in an area that’s served by an unreliable power grid, especially if you work from home and need to keep your computer gear up and running during frequent outages.
But as awesome as battery backup devices are, all consumer-grade models share one major disadvantage…
Their batteries only have enough storage capacity to power your devices for a few minutes. In fact, even a relatively expensive 1,500VA model will only keep a typical home computer setup running for about an hour.
That means if your power occasionally goes out for longer than an hour at a time you’re going to have some down time.
But guess what? For just a little more than you’d have to pay for a quality 1,500VA commercially-built battery backup device you can build your own “home-brew” battery backup system that can keep your computer, monitor, modem and router all up and running for several hours during extended power outages.
This is a good time to present my semi-standard disclaimer…
Important: This project involves the use of a lead-acid battery and a power inverter that produces 110 AC volts.
Although this is a very simple setup to put together, there are still some very real risks involved.
Therefore, if you don’t feel comfortable working with these types of items and/or you don’t have the skill set required to do so safely, I recommend that you either skip this project entirely or ask someone who has experience working with these types of devices to help you.
In short, before proceeding with this project you must agree that if a goat ends up eating your car and burping up a tricycle, a mid-summer snowstorm kills all of your petunias or something goes seriously wrong with your home-brew battery backup system, you agree that it won’t be the fault of your humble tech blogger (namely me).
Now that we have that out of the way, you can proceed if you wish to.
What you will need to build a “home-brew” battery backup system
Despite the relatively low price and much longer run-time, this home-brew option is incredibly simple to build. All you need are three components:
1 – 12VDC to 110VAC Power Inverter
2 – Battery Charger
Note 1 – I believe the specific items I linked to above offer the best cost to performance ratio for this particular project. That being said, there are plenty of similar devices on the market that will also work if you have specific brands that you prefer to use.
Note 2 – Lead-acid batteries should only be discharged to 50% capacity to avoid damaging the battery. You could effectively double the run-time of the connected device(s) by using a LifePo4 battery instead, but that will also effectively double the amount you’d have to pay for the battery.
Once you have acquired all the parts, simply use the charger to charge the battery to 100%. After the battery is fully charged, disconnect the charger from both the battery and the 120V wall outlet.
When the power goes out, connect the inverter to the battery according to the included instructions (be sure to pay careful attention to polarity), then plug your computer, monitor, modem and router into the inverter (using a power strip) and you’ll be all set.
Be sure to top off the battery charge once a month or so to keep your home-brew battery backup system ready to use when you need it.
And now, here’s a little bonus tip…
If you keep your computer equipment plugged into an inexpensive commercial battery backup device instead of a power strip, you can simply unplug that battery backup from the outlet and plug it into the inverter on your home-brew battery backup when the power goes out. That way your devices won’t shut down at all due to the outage.
Then when the power comes back on simply unplug the commercial battery backup device from the home-brew battery backup and plug it back into a wall outlet.
What you can expect in terms of run-time…
Of course the actual run-time you’ll get out of your home-built extended run-time battery backup device will vary according to the number of watts each device that’s plugged into it consumes.
The good news is most modern computers, monitors, modems and routers don’t draw anywhere near as much power as their vintage predecessors did, which means you should be able to easily get five hours or more of run-time out of a single battery charge.
And of course you can expect to get a lot more run-time if you have a laptop instead of a desktop computer.
Remember not to let your lead-acid deep cycle battery discharge past 50% in order to prevent damaging the battery. You can avoid this limitation by using a LifePo4 battery instead of lead-acid.
Here’s the bottom line…
You don’t have to settle the mere minutes of run-time you’ll get out of a commercial consumer-grade battery backup device.
You can easily build your own home-brew device that’ll keep your essential gear up and running for hours!
To finish up, although it’s entirely optional, I strongly recommend that you watch this short, but very enlightening video that explains in more detail how all of this works. It’ll really help you understand exactly how this type of setup works.
Note: You can watch this video at full screen by clicking the little “square” icon in the lower-right corner of the video after it begins playing.