TC Projects: Lead-Acid Battery Backup

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Sometimes life throws curveballs. But rather than just get hit in the face, why not do something about them? This video is a mishmash of a project, some insight on Lead-Acid Battery technology, inverters, and applications. A bit different you might say from TC’s normal stuff, but what’s life without a little variety?

*There are definitely different ways to charge lead-acid batteries, with different strategies optimized for different results. However, for general 12V applications, a large battery and a slow-ish charger for a car battery will be an A-OK combo.

Here’s a link to the battery monitor–a really neat thing, I should say:

As far as batteries and inverters, go with whatever you like. But definitely don’t use a car battery. At a minimum, look for a marine deep cycle, and if you can get your hands on a pair of golf cart batteries or a 12v true deep cycle from brands like Trojan, do that.
For inverters, I would recommend a pure sine inverter for most applications, but unless you plan on running some heavy stuff from a large battery bank, what’s shown in the video is way way way way way overkill.

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  1. Dr.JONATHAN’S WORKSHOP Dr.JONATHAN’S WORKSHOP on March 4, 2021 at 10:18 pm

    You should use agm battery

  2. Full Throttle VTEC on March 4, 2021 at 10:18 pm

    My work is the one who sell those batteries and stocks all the menards

  3. Dogukan Çil on March 4, 2021 at 10:22 pm

    Plugging and unplugging is a hassle. If you have a UPS, why didn’t you just upgrade its battery?

  4. Roman Zhovtulya on March 4, 2021 at 10:23 pm

    Why not just replace the small battery in the UPS with the large deep cycle battery? The UPS already has a built-in charger and inverter. Also, you won’t need to keep unplugging the UPS from the wall to the inverter and back every time there is a blackout.

  5. dnwklin on March 4, 2021 at 10:24 pm

    Is there any good stuff to use as automatically switch between wall plug and the inverter?

  6. Niels Raider on March 4, 2021 at 10:24 pm

    Finally ten times better then a ups system

  7. Joseph Lieberman on March 4, 2021 at 10:25 pm

    This is also good to have for home or commercial alarm system battery backup.
    Surprisingly many are highly inadequate.

  8. IceFalken Ace on March 4, 2021 at 10:29 pm

    Will it be cheap to add a filter circuit of some kind to the generator?

  9. mopar1969kr on March 4, 2021 at 10:30 pm

    would it not be easier to wire in the larger deep cycle battery to the ups? i have wanted to try this, most ups systems use the 12v 7ah batteries, replacing that battery with the lead acid should be painless and provide even longer run time without having to run through another inverter. just a thought.

  10. Cameron Stewart on March 4, 2021 at 10:31 pm

    A recommendation for your next video: how NOT to organize cables in a home office 😉

  11. Who Ever on March 4, 2021 at 10:31 pm

    The last car I owned had a bad electrical system. It would blow through alternators every other week (only every other week because I had to wait a week for the auto parts place to get another rebuilt one for me but at least it only cost me time and the initial anxiety of figuring out how to change it from the information in the Chilton when I did it for the first time, plus we had to "borrow" a shopping cart from the grocery store across the street and push the heavy alternator at least a mile to the auto parts store to exchange it). I finally bought a battery charger but there was no electricity in my parking space at my apartment so I had to lug the battery into the apartment to charge it every night. Then I would just hope and pray that it would keep the car running long enough to get back home because, whenever it didn’t, I’d have to walk. At least I was young back in those days. Now I know why the battery was getting worse and worse at this over time.

  12. Adan M on March 4, 2021 at 10:31 pm

    14:00 "Everything is seamless" and continues to manually unhook from wall outlet to inverter tied to battery. What would BE seamless is to crack open that UPS and parallel tie it to your new battery.

    Also, you’re also running your power through 2 inverters with this scheme.

  13. D Sloop on March 4, 2021 at 10:33 pm

    My 1500 watt Tripplite inverter charger (600 dollars) is from an RV, hooked to two huge gel cell batteries and switches automaticly when the grid power goes out. this will power my setup for 6 hours.

  14. sd4dfg2 on March 4, 2021 at 10:34 pm

    I always assumed if the power was out on my block then probably the local cable provider’s equipment was down too.

  15. Davie Dood on March 4, 2021 at 10:34 pm


  16. Abstract Idea on March 4, 2021 at 10:35 pm

    man you should wire a switch so it doesnt need to be plugged and unplugged

  17. Mark Austin on March 4, 2021 at 10:38 pm

    If you replaced the lead acid with a lithium ion RV battery you’d have 4 days of use. A cheaper solution is to use two 6v golf cart batteries in series… Much more capacity for the buck than a marine deep cycle.

    This technology is well used and documented in the RV world

  18. James England on March 4, 2021 at 10:42 pm


  19. Michael Martinez on March 4, 2021 at 10:43 pm

    your emergency set up to convert dc to ac to run appliances that need to convert ac to dc to run.. video ain’t over yet wonder if you mention the irony of it.

  20. LA TEEZI on March 4, 2021 at 10:43 pm

    Great video! As a helpful tip to everyone, could save yourself lots of time and cost. Just open up that UPS, disconnect the leads going to that small internal 12v Lead Acid battery, run leads to deep cycle battery you bought (or even better 12v Lithium Battery) Bam! You got lots of extra run time on that same UPS that likely already is a Pure Sine wave inverter. Even charges that Deep cycle battery when Power isn’t out in the house since it’s designed to keep a slow float charge on the original lead acid battery inside.

  21. Daniel Beard on March 4, 2021 at 10:43 pm

    It’s significantly easier to wire a ups directly to a large capacity lead acid. The only shortcoming is that most smaller inverters are only 1-2 amps on the charge side which makes for lengthy charge times from a deep cycle but a regular car charger can be paralleled onto the battery.

  22. MWXYT on March 4, 2021 at 10:46 pm

    Why didn’t you connect this big battery in parallel with little battery inside the UPS? 🙂

  23. TommyMacDaddy1 on March 4, 2021 at 10:46 pm

    Not sure how this setup worked out. Could use a follow up… please?
    Skyjack batteries may be a better choice over golf cart batteries. They are more expensive-but will last MUCH longer.

  24. Francisco Athens on March 4, 2021 at 10:47 pm

    Some of those devices will take DC (laptop, router, modem etc) would it not be more efficient to use DC to DC voltage converters?

  25. Mostly Guesses on March 4, 2021 at 10:49 pm

    … ummmm, indoors don’t lead acid batteries vent Hydrogen a bit at least the normal open kind even the boat ones, maybe only when charging, this is why Sealed Lead acid batts or thet newer Gel lead acid are used by people living in their vans,, , ,, I worry there is 1 in million chance of explosing, , ,,, that said I had 4 batts on my boat I lived on and I dodged any bullet andd didn’t die…. Just FYI

  26. Fredashay Klavierstein on March 4, 2021 at 10:49 pm

    Frequent power failures are happening all over America, not just around Chicago.

  27. Erik Sundberg on March 4, 2021 at 10:51 pm

    Could of just rigged the bigger battery to the APC UPS power strip.

  28. Alex Daves on March 4, 2021 at 10:55 pm

    My favorite part of this setup is converting AC to DC to charge the battery, then inverting DC to AC to provide wall power from the battery, then converting AC back to DC for the electronic devices.

  29. MRCNC1967 on March 4, 2021 at 10:56 pm

    Would be nice to know if this setup has been put to work at your mom’s home office since the install? Follow up conextras video?

  30. Ingax on March 4, 2021 at 10:56 pm

    SLI?, so you can but a high bandwidth bridge between them and have double the performance?

  31. BRL on March 4, 2021 at 10:57 pm

    Why not just connect a really big battery to the UPS in place of the undersized battery it contains?

  32. Northern Vault on March 4, 2021 at 10:59 pm

    I was looking for a cheap and simple setup to run the propane fridge and heater of my pop-up tent trailer. I think this is my solution. I had something like this in mind, but every video I found were about overly complicated system that could support an AC unit 😂

  33. Jammin Wrenches on March 4, 2021 at 10:59 pm

    You could do the world alot of good if you started your own university.

  34. StainX on March 4, 2021 at 10:59 pm

    American power outlets always staring shocked at you

  35. Nate Behra on March 4, 2021 at 10:59 pm

    Im super late to the party but why not use a honda (or similar) inverter generator?

  36. Doug Golde on March 4, 2021 at 11:00 pm

    Buy a lite weight, efficient, clean power, inverter based generator.

  37. jian tan on March 4, 2021 at 11:01 pm

    When you are about to die, a wombat is better than no company at all.

  38. WI Fox Valley Lifts and Alarms by Bearlovesox on March 4, 2021 at 11:01 pm

    Nice video demonstrating the difference between regular and deep cycle batteries. I work in the outdoor warning siren industry. Tornado sirens nowadays typical take 4 or 6 deep cycle marine batteries wired in series to provide 48 or 72VDC that have a load of 100-300A on average for their three minute cycles. Definitely not a job suited for the standard car batteries!

  39. Kosma Terpilowski on March 4, 2021 at 11:03 pm

    The dirty power could be stabilized with a transformer

  40. TheSysops666 on March 4, 2021 at 11:03 pm

    7:15 Ah ah ahhh! If you put government in charge of it then everyone would complain. Such is the failure of government and the success of the free market.

  41. Emma Hill on March 4, 2021 at 11:04 pm

    Are these still your recommendations now, or are there new options.

  42. James Drissel on March 4, 2021 at 11:06 pm

    I think I am going to build something similar, though I am going to use 2 inverters, both small ones. One will power the router and fiber endpoint for Google Fiber (and a few other network odds and ends) and the other will power my CPAP. I plan to use a 30A 12V linear power supply tweaked to 12.56V to keep the battery topped up. Audio Authority actually sells a very expensive power supply intended for use this way. I had one at a shop and if we had a battery in stock for more than a month we would put it in parallel with the MB88 that powered the audio displays for a day. We used about 60′ of 10G wire which prevented huge currents from connecting two batteries with very different charge states. We never had a dead on the shelf battery and the interstate rep was puzzled why our swapped out batteries were so much better than the other shops on his route. The only thing really special about that expensive power aupply was that it was set for 12.6V (I seem to remember using a fluke bench meter and getting 12.560 steady as a rock from no load up to over 50A. It did not drop below 12V until almost 1000A was drawn from the system, and that was far beyond what the audio displays could draw even on peaks.

  43. P. Wingert on March 4, 2021 at 11:08 pm

    I’m in an interesting power situation. I have brief power blinks lasting less than a second. I am using an Eaton 5S UPS which is an inline UPS. when the power blinks on the circuit I lose all devices connected in the apartment. including the two NAS units connected to my UPS. All the usual tests have been done. put test load on UPS unplug from wall and plug back in. No evidence of loss of power under this scenario. the unplug time here is about 5 -10 seconds. Consulted with Eaton and they have recommended moving to their 9PX double-conversion UPS with an additional battery pack. The total cost of that solution is $CDN5,000. Eaton has indicated the transfer time on the 5S UPS is 5 ms and believes the issue is the blink is below that and that the sensor that triggers the change to the battery doesn’t detect it before it switches back. During the brief, an estimated 3 ms of transition. Your system looks like a solution. Comments on this issue and the applicability of your solution would be appreciated.

  44. Vincent Quinn on March 4, 2021 at 11:08 pm

    Why not just run every thing off the inverter all the time. Leave the automatic charger on all the time. Get rid of the old UPS. With a typical 50 Watt drain it should run for years. If the drain goes up for a while the battery will buffer it. It’s called a full time UPS.

  45. Austin Buerkle on March 4, 2021 at 11:08 pm

    why not connect the large battery to the UPS and remove the sine wave converter from the system?

  46. musikSkool on March 4, 2021 at 11:10 pm

    Hey, could you use that "Kill A Watt" on cheap space heaters and expensive space heaters, as well as a 2nd hand store space heater? I suspect that the expensive kind jumps to max watts very soon, like less than 5 minutes, while the cheaper ones take maybe up to an hour to reach their rated heating output. And the 2nd hand space heaters may never reach their rated watts because of metal fatigue or some other wear and tear on the circuits. Yes, I am still a little annoyed by your statement that all space heaters are equal if they have the same watt rating. Clearly how fast a space heater can heat a room is much more important than what its max power draw is if left on for far longer than you would hope it would take to warm you up. Only a little annoyed though. Everyone has a blind spot and I have learned so much more from you than I have noticed that you didn’t know something. In totality, I’d say your accuracy rate is well over 99.9%. I also noticed something about your converting VHS to digital video where you didn’t go as far into modern TVs "limited range" confusion causing terrible black levels in some videos, but that is a cutting-edge problem so I can’t expect everyone to understand what is going wrong. It feels like the 16×9 and 4×3 problem we had when DVDs were getting black bars and TVs sometimes had multiple black bars both shrinking and distorting the frame until it all got sorted out. I recently watched an "Indiana Jones" movie on Netflix and it was either the TV, the internet browser, the plugins, the videocard drivers, the videocard settings, or even a noise reduction setting somewhere in the process, causing the black level to crush all detail in any shadow. Ugh. We are in the middle of a change, and until it is finalized, it is pretty irritating.

  47. Vincent Cleaver on March 4, 2021 at 11:10 pm

    So how has this set up worked out since then. We need an update

  48. Junker Zn on March 4, 2021 at 11:13 pm

    Heh. The insulation on those thin wires will catch fire before they melt. Not bad for a quick and dirty backup, though honestly you don’t want a lead-acid battery operating indoors under any circumstances. These days you can use a much safer LiFePO4 (also known as LFP) battery and a cheap charge controller and just leave the thing connected 24×7. LFP batteries use a very nice, safe, chemistry that isn’t as prone to fire as a traditional lithium ion battery. Or, of course, these days, just buy one of those lithium battery packs that have everything built-in, like a Jackery or something (most have traditional lithium-ion batteries inside but more and more are starting to be equipped with LiFePO4 batteries).

    Now off to look for any newer battery stuff you’ve posted since this one 🙂


  49. Louis Co 360 on March 4, 2021 at 11:13 pm

    Nice cable management

  50. Pottema on March 4, 2021 at 11:17 pm

    Power outs in the great America,….. mouhahahahahahaha!

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