UPS Battery Backup Teardown And Repair 

1) LIthium ion isn't suitable for UPS applications, because they degrade if kept fully charged. 2) The cost for lithium ion with the same watt hour capacity is higher than lead acid. 3) The higher weight of lead acid compared to lithium ion is not an issue with a UPS, since you don't have to move/carry it around. 4) Lead acid can be charged in series with no problems, lithium cells in series require a balancing charger to monitor individual cell voltages. I have three UPS units and all of them use two 12V batteries in series for 24V. Lead acid is a much better choice for UPS applications, that's why all the manufacturers use them.

You seem to have much more energy these days... it's wonderful to see! Thanks for keeping the interesting stuff coming...

"Reverse thread method" So great to see someone else understand that!! I've seen so many folks 'double-thread' plastic holes and the screw threads don't hold worth a darn. Nice video.

That little heatsink with the big yellow lead on the top is one of the MOSFET switches. They often screw the primary leads of the step-up transformer right to the heatsinks! No need to attach to the PCB/terminals/traces at all. 30-40 amps thru those leads. Looked like the datecode on the PCB was late 2015, so likely the battery was about 4 years old. They usually only make 2-4 years, depending on quality, cycles and mostly temp. so you got a good run out of it. And you used a proper high-current version of that style battery, so should be good for another 3-4 years! Soo many people trash the whole UPS when all it needs is a new battery, then it's good as new again! (Test these things regularly under load for a few mins, only way to be sure it'll hold up when you need it.) Enjoy and stay safe! Stu the batty. (And major battery/UPS/power system junkie...:)

I've used Tripp Lite UPS units for years without any trouble. By the way, earlier today I used your technique to reverse a screw before tightening it. It's a good habit to get into. Thank you.

I found a "Gotcha" when sourcing replacement batteries. You have to pay attention to the terminal sizes of the OEM battery vs the replacement battery. I did get one, by accident, with smaller terminals. I was fortunate that the power leads still fit, although not as secure as I would have hoped. So, make sure if you have a battery with F1 or F2 terminals, you replace it with the same terminal size.

"Negative to negative, Positive to positive..." Ashes to ashes Funk to funky I'm a total FranLab junkie! Sorry Fran, couldn't resist... ;o)

We all just gonna pretend like that intro isn’t the greatest into ever?

I had several subscription videos come up but I watched Fran first because I also have a UPS and decided this would be instructive.

Having replaced tens of thousands of backup batteries in Alarm systems, I can confirm they use the same sealed lead acid batteries as this UPS and usually get replaced every 5 to 8 years after being load tested. When purchasing in bulk they are still far cheaper than other battery types. I have never worn gloves or used a screwdriver and a hammer to replace one either.😊

Coincidently, I have to change some UPSs batteries! Thanks for the video!

I was impressed you were able to get an exact replacement and the unit you had seemed very serviceable

Nice. I turn around a lot of APC UPS's; they have two batteries in series. More of less the same procedure, except the APC units have a port connector, cable, and software to run on the protected computer. After renewing the batteries, you have to tell the software that you've done it or it thinks it still has an old battery in it. Changing the date makes a big difference in how the UPS behaves afterwords. You rock! :-)

Good reminder to do that. Thanks Fran.

It's Fran!!! "It is". Really deep!!! Thank You Very Much.

As soon as I saw the battery I thought 12V8AHT2. I've replaced hundreds of them in Fire Panels, and some in emergency backup lights. Good video Fran.

Yay, real Fran is back! ;-)

I hacked mine for more blackout performance. I extended the 12V cables to a 100Ah deep cycle SLA that is also charged with a 200W solar panel. The UPS doesn't mind the external charging and it gives me hours of backup power in our frequent blackouts. A couple of additional mods needed for continuous use include a fan to keep it cool, switched using the HV relay coil. I also added a mute switch to the alarm. We had a 3 day power outage during recent bushfires and I had no loss of internet time due to loss of power. I also frequently spot these small (~500W) UPS's at the local recycling centre for just a few dollars, only suffering a dead battery that causes most people to throw them away...

Dang! I did not know women knew how to use a soldering gun... Just kidding! Always a joy to watch you and listen to you frame!

YOU and Mr. Carlson's Lab - both fantastic! :)

cool follow up to the whole LI-Ion issue. Plus there are tons of valuable (and sometimes high-tech) UPS's in the garbage simply because the battery stopped working, so lots of good-works to be harvested and money to be saved by renovating them

I love my UPS. I think that we have the same one. In our neck of the woods, power failures are regular events. Some PFs are short and there are moments when a nearby transformer blows and we have to wait a day or more. A UPS has saved our tech.

I wish my science teacher was like you. Ty

I find 3 to 4 years to be typical battery life in my UPSs.

My APC-branded UPS does a regular self-test so you know the battery has expired BEFORE it fails during a power outage.

I changed the batteries in my CyberPower last year, it uses 2 instead of one larger one. As long as the software monitor supports your OS, its worth it to replace batteries instead of the UPS. My first Belkin UPS didn't support beyone Win XP so I trashed that one. Good to see you posting videos again, Fran fans miss you.

I made my own UPS/backup system using a Finder 10A relay + a large truck battery (1050 CCA) + a 20A car charger + Sunforce Pro pure sine inverter.

I have this exact unit also. I use an "online" enterprise UPS for my actual computers but I have this little guy for a wireless bridge and remote backup drive. It's definitely a trooper. Just change the batter every couple years. The biggest reason for the sealed lead-acid style batteries is that they handle long-term trickle charging as well as overcharging pretty well. You can get a high-current output with a cheap battery and pretty basic charging circuitry. Makes it cheap, easy and effective. Great quick video!

I was a sysadmin for a moderate size private university in Pennsylvania long ago. Being on of the junior people I got assigned the grunt work jobs like supervising the computer room when the Emerson tech were servicing our Liebert UPS. I was there when we had to replace the batteries. They handled it but I had to provide the muscle to get them from the front door to the room the day before, and the pallet would not fit into the building elevator (the building had been constructed in the 1950s as the library) so got to repeatedly handle 30 lead acid batteries a bit bigger than typical car batteries.

Great Video!

Nice solid UPS!

Thanks great video🙂

That's pretty timely, I just bought a CyberPower UPS, I live in a rural area with lots of brief power outages and electric storms. I'm toying with the idea of connecting an external deepcycle SLA battery for longer run time. It's not a cell Fran, it's six cells in a box! Thanks for posting this :)

The only linear supply in there is used to charge the battery. Most of the electronics is an INVERTER, to make 120VAC from the 12VDC battery.

When I remember right, the big coil/transformer is there mainly to make 'kind of a sinuswave' from a stepped blockwave. I expected more of a teardown of the boards with more info on the parts ;-) In the APC-ones I have used and some were defective, I noticed the voltages were stepped in stages to a square-like form or in 4 intervals. Put that to a big coiled transformer and you end op with a signal that looks more like a sinus. But cheap UPS's don't usually give a real sinusoid result (check your scope), worse then normal inverters do. Also noticed that the consumer-units do generally use the heatsinks more like a temperature-buffer: they heat-up but since the UPS will turn off in a short period with higher loads that is not such an issue as with real inverters that are meant to be on all day (from solar-power for example).

I replace the batteries on these things regularly as part of my job, both for individual workstations and in the machine room rack mount versions. In my experience, the UPSs that don't have their own cooling fan tend to die a lot faster than the ones that do, and it's generally the capacitors that go bad. (I no longer order any UPS without internal cooling.) The bad capacitors would be easy to replace for a few cents instead of replacing the whole unit for $150+, but for insurance reasons, we have to recycle them. The potential fire hazard of a big honking transformer that's had its warranty voided by the end-user isn't worth the risk.

just bought an 810 watt APC UPS to join with the new custom pc on the way. I'm glad to hear that yours has lasted you so long. When I was reading reviews they were really polarized, everything was either a 5 or a 1, the best thing in the world or the worst purchase they've ever made, conked out on day 1 type stuff. So I was having a hard time making the decision, I went with the APC cuz the batteries are easily replaceable, I can't imagine it going 8 years without 1 though :D

I have a Tripp Lite ups much older than yours, maybe form the PC XT era. A model for 220Vac 50HZ 450VA. I rescued it from a dumpster 18 years ago and I still use it. A very reliable artifact. Maybe because it is that old, it has zero "chinessium" components inside and it's simply bulletproof!

Yay Fran!!

another nice video.

I bought an EATON brand backup about 9 months back new - it also uses lead acid. Seems common for these sort of units.

You can often find 'dead' UPS's where the only reason they aren't working is they need one or more new batteries. The batteries are usually far less expensive than the cost of a new unit, especially if you get really lucky and find a commercial grade one.

Nice! 😉👍

That is 100% the exact same model I had at my old job. It worked perfectly for 8 years, then we had contractors rewire things, they broke one of my monitors, and the next power outage my computer died (so I suspect the contractors killed the UPS as well. I think the broken monitor was the one not plugged into the UPS, to save time if I had to shut down fast). Replaced with a similar model, but wow. This is such a flash back for me!

Awesome. Most people would have thrown it away instead of getting another battery!!

I remember seeing a UPS that was the size of a refrigerator. It was used to keep not only the computers running but also the lights in the room. And it was backed up by a diesel generator if the power outage lasted too long. Talk about overkill!

I've gotten tired of replacing batteries in some of those. I gave up and made a bulkead plug using Anderson Powerpoles and made the battery external. Some of those have weak screw holes, hidden screws, and hidden latches you have to pry apart. After a while it just doesn't want to go back together.

I use an old APC SmartUPS 1400 at home to cover our TV, internet kit and 1 energy saving lamp in the living room. I removed the internal battery and have wiring going outside to a weatherproof box that contains a car battery. This gives us about 4hrs runtime in the event of a powercut.

We have a couple UPS's for our PC's and routers, older APC brand, and they output modified sine, not pure sine, perfectly acceptable power for the switching power supplies in the devices. Batteries last about 3-4 years then need replacing, but the UPS's themselves last a long time.

If it has been in service for ten years, God bless. If you haven't replaced ALL the electrolytic caps, you still have work to do.

You rock... Have a UPS I need to replace failed caps on. You inspire me. Thank you.

I've never really needed a UPS until I moved out to the country and every winter we get at least two outages, and one in summer if there's a wildfire. I have two 1500VA, one for my router, fiber "modem" (i forget what it's called), and an AT&T Microcell (mini 3G cell tower) that can last for 2 hours; and a one for my computer that can last 20-40min depending on whether it is under load. The computer's is connected to the USB to send a shutdown signal.

New build semiconductor plants are built with all kinds of power backup - a single power outage could be millions of dollars. Some older plants ran on a diesel generator and it needed a lot of human intervention to keep furnaces at temperature and bring up all the workstations.

Li-ion UPS's do exist, VERY expensive, APC makes a few

5:55 So Fran can TIME TRAVEL! That is just so typical.

Fran, I may be mistaken, but that cap on the top right of the pcb looks to be a bit strange, like the tri impression on the top is separating? It doesn't look bulged tho, so hopefully it's just a trick of the lighting. Go to 3:29 to aee what I mean

Good video Fran. SLA batteries in UPS should be changed every 3 years. You need to check how they switch over every 6 months. Remember most UPS are not designed to keep your load going for any great length of time. Most like yours are to hold the PC up while you do a civilised shutdown, not keep working. There are UPS designed for full load continuous operation, but they are not cheap or small. I thought you might have tested your UPS after fitting the battery.

So cute 😍

I used the same batteries for one of my products and, for info, they last three times longer than identical but unbranded far east knock offs. I used one to check looms and boards to see if I had the doohickies and whizzers round the right way, and it still takes a charge twenty years later.

love the classic TI-30 on the bench. Unfortunately they didn't increase in value like the TI-59 (yet).

I didn't know that other people did so, but I have always screwed counterclockwise first for the same reason

I'm in the habit of unhooking the negative first and hooking it up last. In cars, at least, the entire chassis is ground. If you pull the positive while the negative is hooked up, there's a possibility to bridge the positive terminal to the car body with a tool or to touch the terminal with your hand while leaning on the car, and then completing the circuit. Pulling the negative first protects you from there, though the possibility of bridging the terminals reminds.

Those UPS units now are using a smaller transformer, running a lot further in saturation, to cut the cost down. As well no more copper wire in them, all CCA wire instead. The heatsinks are literally that, a big block of aluminium extrusion there to keep the power devices cool for 15 minutes by absorbing the heat, then cooling off when either power is restored and they are no longer switching, or the battery is flat and the unit has shut off. I always take those spade connectors and tighten up the socket side with a pair of pliers to increase grip, and generally a smear of white grease in them to keep the battery acid from corroding them away should the terminal do the usual thing and seep acid, as these are common to do, especially with the terminals down like that. At least that one only gently cooks the battery, having the hot power transformer above it, so that there is a semblance of air flow over the battery, many have what looks like cooling slots, but they are all dummies, and the battery is cooked inside. The entire control circuitry is connected to mains, only the external data interface is not, especially in these lower cost ones.

Dear and beloved Fran! come on pliz Frantone Vibutron !!! we need you !

Nice video as usual..... the outro song kills me :-D

I just changed the batteries in my 3000VA UPS. It weighs 50 kilos or 110 pounds.

1st off, i enjoy your vids, ty. 2nd.... A. they make plenty of Li-ion 12v replacement batteries, i suggest Lifepo4. B. those little UPS's are not full sine-wave units, those are larger and have more complicated electronics. IF you want full sine-wave, i suggest looking into used medical UPS units. they are usually 36v units (3 batts in series) and then make a LiIon pack to fit,... it's not hard and those UPS units are designed to run for longer times (bigger heatsinking, active cooling, etc.) and you can usually wire them into ext power packs as well. i have 3 used Med grade Trip-Lite True Sine-wave units i got used for $5 each at an electronics recycling place in FL. Batts we're swelled up and cracked some of the cases but once mod'd and put to use, i have NO CARES! they work GREAT! I can run my entire entertainment system on one unit, with 36v custom built cell pack for about 7 hrs with everything running.... the pack is smaller than the stock 3 batts and charges off the stock internal charging system. It's really not hard to upgrade these to Li tech if you want to, and it's totally worth it. The Med units, like i said, are true sine-wave so better, cleaner and can function like proper AC line power for picky electrical devices. Keep up the good work and learning each day! :D

The batterys are intends by regular replacement. All two years is replacement, in hospitals every year. But hospital ups, as for sugery, hold two batterys. If electricity goes and one is empty ups work anyway. And you change one battery the other keeps inside.

I believe they are IGBT’s (insulated gate bipolar transistors) that handles the 60 hertz. They generate some heat

Usually about 3 batteries in, I find the charge regulator starts to fail....older ones used a PB137 charge regulators, some blew up on me.

Good on Tripp Lite for using a standard battery and terminals. Cyberpower is like that as well. The APC I had was evil and used a proprietary connector so you had to buy a new battery for an inflated price from them instead of just getting a standard battery from anywhere. Lead acid does just fine in UPS applications, I don't think lithium ion would be a great idea. They degrade quickly when stored at full charge which is what they would be doing in a UPS. Plus their more explosive nature might be problematic.

I cannot seem to find UPS batteries that last more than 4-6 months. Years ago, I could buy those batteries and they would last 3-5 years. Can you , please, recommend a solution?

I just created a whole house UPS running off two nissan leaf battery packs. Also charges from solar panels but I can run my entire house for a couple of days even with no sun.

I'll need to research this a bit more, but we have quite a few UPS's that still do not perform correctly after we've switching out the old batteries for new.

You may not need to replace the battery, depending on the age. They dry out. They are AGM. Very little water. It cooks off after a very short time with the battery being float charged. Add distilled water to each cell, like 30 mL, depending. The battery will work again almost perfectly if it's not more than a couple years old.

As I recall, jehugarcia recommends LiFePO4 for UPS applications because they last longer. Significantly more charge/discharge cycles. LiFePO4 batteries have a slightly lower fully charged voltage so a 4s1p configuration is compatible with a 12v battery.

Fran, I just discovered your channel last weekend, it is amazing! It is important to know the history of technology and like TV's "Mr. Wizard", you provide an excellent resource. Would love to see more "tube" stuff, maybe a one tube amplifier, bread board of course. Elaborate some on Soviet extended reliance on tube technology in fighter aircraft. "Nixie" tubes? Grandfather purchased 500tons of war surplus, here at the farm. Hardware included Nike "Bay Of Pigs" missile launch systems, lots of "nixie" panels. B-36 bomber support hardware and unknown to many, "SniperScope" hardware. Grandfather was always above the propaganda BS we as citizens were beat down with. Loved the Saturn V circuit boards, your guitar building and playing, Sputnik audio recreation! Have you read the LOUIE FENDER STORY??!! Its a great little book. Your endeavors match mine to "T". Yes , I am an AM radio (night time, ) DX'er, listener, some short wave too. Fender Gibson tube amp collector, aviation pilot, farmer, YUP!

APC do some LiOn battery based UPSes now, but only in 19" form factor afaict. More expensive than their lead acid equivalents too, I think.

you are very good and nice

This isn't exactly a big linear supply. The transformer (in your case, something like a 120V/12V transformer) is used for charging the battery when the line power is available. They most of the time use the body diode of the MOSFETs as a full bridge rectifier. When the line power fails, the relay connects the high voltage side of the transformer to the load/ disconnects from the mains. And the MOSFET H-bridge drives the transformer from the battery. Using a transformer limits the amount of filtering needed as well because it blocks some of the high switching frequencies.

Lead batteries are still cheap and very good at sitting in applications without portability requirements, being trickle-charged and then delivering a kick over maybe five minutes. I could imagine those supplies to switch to LiFePo cells, those are a bit more well-mannered and suitable to just sitting there fully charged most of the time, but I'm not sure about the discharge characteristics.

I'm guessing this is a cheap 'modified sine wave' unit. If it is, I'm surprised they're still using a big iron transformer. AFAIK it's cheaper and more efficient to use a high frequency DCDC converter to make 150-170 VDC and use an H-bridge to get an alternating output. If it is a SmartUPS-like pure sine inverter, then it makes more sense because they use the same transformer for charging and discharging the battery. It's actually pretty neat, and it made me realize that a boost converter with synchronous rectification, viewed from the other side, is the exact same as a buck converter with synchronous rectification.

The batteries went in my APC Smart UPS 1000 (an old UPS I got from work when the server was retired). I did consider getting LiFePo4 batteries for it, but at about £200 for a pair including delivery, I ended up just getting another pair of SLAs instead for £45 including delivery. In the 3.5 years the last two lasted, we only had one power cut that lasted over an hour. The rest were all brief such as the RCD (ground fault breaker) tripping out the sockets. Besides the higher cost of LiFePo4, I was concerned about hearing that a constant float charge shortens their life, i.e. while they handle being kept at 100% charge much better than common Lithium Ion batteries, this needs to be carried out by periodically topping up the battery instead of applying a constant float charge voltage that a UPS does with SLA batteries.

I replaced the battery in my UPS and it charged up to 13.42 volts and does put out 122 volts but the low voltage LED lights up and it beeps while using it. New battery. Any idea why the low voltage led would light?

Red to red, Black to black, Throw the switch and stand well back.

Thanks, Fran, for your videos. I'm a new subscriber and have been looking at some of the older ones. I love your new intro. Clack, Clack! That display is fascinating as a transition from mechanical to today's silent displays.

I would believe that Lead acid battery would be cheaper to produce than Lithium batteries, and they are well suited for high discharge current. As for as the output, I would like to see if the output running in battery mode is actually more square wave than sine. The only way to see this would be unplug it. Put a load on it, and see what the waveform looks like on a scope. On the subject of drive transistors to form the AC output from the inverter while running on battery, I suspect that the are insulated BJTs. These transistors are common for industrial motor control units, and they would be suited well for inverter purposes.

Well my APC UPS takes two SLA's. At $15 each, it's still cheaper than another unit.

In our area that power interruptions that last for hours. I replaced the battery of our UPS with car battery. I don't know if it is a good idea but it works, lasted a couple of hours powering some networking gear. I slightly modified the unit adding a cooling fan. Running for 9 months so far..

It’s a product I have never used. When I worked at a large manufacturing plant I suggested to one of our managers that we invest in one and he replied that he didn’t see losing power on our PCs for 30 mins as a huge issue.

Most likely ASICs that generate the PWM switching waveform for the Power FETS

Where’s a good place to get the replacement battery?

The output on these cheap units is almost always a modified square wave (which they market as a modified sine wave).

I got one for my router/modem/switch and computer for 5 minutes to support a controlled shutdown. Worked fine, but I lost Internet anyway. Doh! Forgot I have a cable amp in the attic. So I found a less expensive smaller UPS for that. I still wonder if Comcast stays up during power outages, but so far all my problems can be attributable to my own stuff. Wish me luck -- this stuff is expensive. Consider showing your viewers how close to a sine wave the battery-supplied 60hz is for this device.

Good idea on the gloves with the acids involved, if the battery did happen to leak you have some protection. A good quality SLA will last a good long time, my last UPS battery (OEM) lasted over 10 years, I replaced it with a cheaper version from Amazon, it crapped out after 2 years, I always date replacement items so I know exactly how long they last. Lithium batteries still aren't as safe as that SLA, and I have yet to see any kind of lithium battery that would last as long as 10 years. Like you always say, always start screws like that backwards to find the thread, those self tapping screws will strip out the plastic and then they don't hold any more, actually its a good idea even when you aren't screwing into plastic, cross threaded and stripped screws suck! I've been doing that for a long time.

Got 2 UPS at my cabin, there connected to 2 banks of 12 v car batteries of 2 batteries each bank that is kept charged by 2 car generators for off-grid power. This gives me the AC I need, but some of the lights are 12v DC along with the Ham radio HF, 2 meter and CB. There a main power switch going to the UPS on 12 v side so the UPS doesn't draw from the batteries when AC is not needed. BTW Bug out area for me.

Hi Fran, looks like I have the same model of UPS, Can I use a 12V 34W battery instead of the 12V 35W battery?, this is because I can't find the exact replacement battery in my country, thanks in advance.

The Battery brand in that unit Yuasa, that is the same that I remember seeing in Japanese motorbikes, I think they are a good brand.. I used one of these to run a small boombox when the power was off for about 5 hrs,it worked well but was more noisy maybe because it was a modified square wave.

It's unlikely that model UPS has a pure sine output - more often they have a "modified sine" output, which is really just a two-step square wave. Scope it out :-)

Those batteries are shipped charged since they will freeze if shipped in winter uncharged. And lead acid batteries do not take kindly to complete discharge either. Did you test it off line?