Mike, if you want to force the unit to relearn its endurance on battery power, you have to put about half a load to it, and execute the self test multiple times a day for about 3-4 days. Hold down the power button while its turned on for a total of 6 seconds. 2 seconds will power the unit off, and you get the single beep, DO NOT LET IT GO, continue to hold it for another 4 seconds and you will get a second beep, then release the button and it puts the unit into 'Self Test' which forces battery usage for 5 seconds. another way to help it relearn, is cycle the batteries, go full charge and then run them down on a roughly 80-100w load , when the unit dies, hold down the power button and force a 'brain dead' sequence upon it. hold the button for 5-15 seconds. APC Backups units have logical sense in them. clearing the logic by forcibly doing a logic brain dead procedure clears its prior memory of the batteries it once knew. after a few times of fully cycling the batteries you should start seeing some really impressive numbers as the unit re-learns the numbers as it works.

May have been mentioned by someone else earlier, but two major items to keep in mind when increasing the runtime of ANY UPS unit... ITEM 1 - "FLOAT CHARGE" CAN BE WAY TOO HIGH FOR DIFFERENT BATTERIES The "float charge" voltage ("standby" voltage the UPS keeps on the battery(ies) at all times when they are not being discharged or charged (just sitting there in standby)) can vary by a significant amount depending on the battery type used. The vital information here is that the float charge for one type of recharageable battery (e.g. an arbitrary typical SLA battery) can be a LOT different than the float charge for a different type of rechargeable battery (e.g. a marine-type Deep Cycle battery). It can even vary from one type or model of SLA battery to another type or model depending on manufacturing. From what I've observed, many models of UPS units typically provide a float charge voltage that is too high...even for the originally supplied batteries. What this can mean is that the batteries may not last as long (edit to add: 'as they should last') because the float charge being too high will, over time degrade the batteries faster than if the float charge was set at the right voltage for the batteries being used. Example, instead of supplying a specified float charge of 13.5V to 13.8V for a given SLA battery, the UPS may be supplying a float charge of 14.5 to 14.8V. I have measured such high float charge levels on various UPS units. A suspicious person might conclude that UPS manufacturers intentionally use fractionally higher float charge values to cause early life battery failures in order to increase their replacement battery sales. *_A float charge higher than the specified value for a given battery WILL take months to years off the battery life of that battery, depending on just how high the float charge voltage is above the level specified for the batteries_* I recommend batteryuniversity.com for more information on "float charge" and how it can damage batteries to cause significantly earlier battery failure. (edit to add: 'I have no personal or financial interest in anything associated with batteryuniversity.com' ) ITEM 2 - UPS OVERHEATING DUE TO LONGER RUNTIMES Some UPS units are designed in a way that they are LIMITED in how long they provide backup power due to overheating issues. If they run too long (e.g. users replace original batteries with MUCH higher Ah capacity batteries) then an UPS can overheat and possibly cause catastrophic damage to itself and/or attached devices due to uncontrolled output voltages caused by damaged control circuitry. When I've added higher capacity Ah batteries for longer runtime, I always make sure that the UPS unit will not overheat due to the longer runtime. This may be a simple matter of not keeping the UPS in a closed storage area, or adding more ventilation to the storage area, or even adding more ventilation to the UPS case. I have also installed a fan in two units (one CyberPower and one APC) as they started reaching dangerously high sustained temperatures when they ran for longer than about 20 minutes. (edit to add: 'Running at sustained high temperatures is not good for ANY electronic equipment and at the least can cause early equipment failure. In particular, very high sustained temperatures (even higher internal ambient temps) can cause electrolytic capacitors to vent and cause failures with unpredictable results.') *_One should not always assume the UPS's self-protection for overheating will always work and provide a controlled shutdown, or that a given UPS even has such protection built into it_*

Instead of the conductive metal hose clamps, you could use large plastic zip ties pulled down tight - non conductive. And yes, those batteries definitely need vented to outside. Hydrogen has a very broad explosive range, 4.1 - 74% and very light, rises up.

Great video! I'm with you on off-grid power.

Still going strong after 18 months. The UPS charging circuit brought the batteries all the way up after several days, and since the batteries are so large, it's as if the batteries are on a trickle charger, like they would be anyway. The minute counter on the display is still meaningless, because the UPS has no idea how big the batteries are, but it is somewhat useful for judging relative charge. The minutes just tick down at a much slower pace. I haven't needed to use them for more than about an hour or so since I installed them, and the internal charger on the UPS worked just fine. Now I plan to use my large auto charger if I run them down a lot so as not to strain the UPS charger circuit. So far so good... Stay tuned.

Hi Mike. What you probably don’t know is that APC sizes their components to match the runtime of their batteries. Attaching a super large battery, and a full capacity load, will eventually cause most UPS models to overheat. Instead, use the TrippLite automatic PowerVerter if you want an external battery bank. That’s what I did 20 years ago. They are also fan-cooled.

I did the same thing a while back. This set up works but one thing has to be considered, UPS' are not design to work for extended periods of time. They have very small heatsinks on the Mosfet/transistors and most don't even include a fan to keep them cool so they end up getting damaged by overheating. Of course to help on this issue you can add your own fan.

I think everyone would have liked to see this work. As well as some runtime information!

You have to plug in the Data communication cable to the system and install the software and calibrate the battery and change the status as new battery it will give more backup hours

Terrific video! I’ve been wanting to do this too. Perfect garage/shed project. Cute kid :)

Thank you for this video. I have several heavy duty ups unit and wanting to experiment . Just gotta get inside the unit to rid that beeping when operating of batteries.

Thannks, i had this idea recently...but for my deep freezer. Lots of power outage recently...thanks for your video

I Love this video. Make more of these in different enviroments please. i promise i will watch them all :)

Great idea, as I have an APC UPS Pro 1300 as well and the batteries are shot too, and I also have a used 12Volt LifePo4 battery too, this is excellent, thanks for sharing your knowledge man, much appreciated.

I know this is an old video, but you can calibrate the ups to those batteries. I found that out with two apc units I have. Just have to unplug let it run on it's normal load untill it is dead and re-charge. My one 1000Va was only telling me 7 minutes after I upgraded it's batteries, but now it shows 45 minutes which is still less but closer to real time. Enough time for me to get out the generator. Just something for you to try to get a better remaining time display.

I have been doing that for years. The best wire that is about 10 gauge and flexible can be found at the automotive shop. I use heat shrinking tube over the connectors that I solder the wires to. In a tight spot getting the outboard battery(s) where you can service them is a real help.

Thanks for the great content 👍

If you are going to do this please install a full time vent system to the exterior. Maybe even move the batteries to a vented box outside and run your wires in. Gases from an unsealed lead acid battery are explosive, especially when overcharging. Like you stated, the UPS has no idea what type/size of batteries you connected. “So far, so good” are famous last words.

The RS 1000 and 1500 models have an expansion port to add an external 24v battery pack, no drilling, no mod necessary. For safety, I'd only use SLA batteries.

I just wanted to mention, that if you take apart the battery pack, it is two batteries connected by a card. You can remove the card and it is much easier to access the leads on the card. They are also marked as positive and negative. The card can only be inserted in the correct way. I plan to try this on my my network rack in the basement.

cool, thanks for the tips!

Mere ups ka out put 3 se 4 impire hai kya me ups k sath 12v 10 ampire charger b laga sakta ho! 1 sath ???? Bettery ko fast charging k lea

The big problem I've run into is voltage drop along the feeder lines from the battery to the UPS DC input, and also within the internal wiring supplying the inverter. I'm running an APC Smart-UPS 750 and under high load (250+ watts) the DC voltage across the inverter input (on the board itself) can be as much as 0.6V less than that measured at the battery terminals. It causes the UPS to think the battery is about to die even though it's not even close. I replaced the external feeders with 10awg and this reduced the voltage drop to about 0.3V, and my next step is to replace the internal wiring with 10awg as well as eliminate as many of the spade connectors as possible as they are all sources of higher resistance and therefore voltage drop. I'd expect the 16awg extension cord you're using to suffer quite a lot of voltage drop; what, if any, issues have you had with that in your case? edit: Be advised, when you calculate the number of amps using I = P / V , the number you get is the *average current* drawn, averaged over time. In reality, the current drawn from the battery is not a constant current, it is a pulsating current consisting of periods of current draw, and periods where little current is drawn. Thus, I = P / V tells you 25A, the average current over time is 25A, but because the current is pulsating, the pulses will actually be well in excess of 25A, and as a result, voltage drop will be higher than you would expect if you simply used V = I / R without further consideration. To illustrate, consider a constant 2A through a resistance of 1 ohm. By P = I^2 * R, the power dissipation is 4 watts. Now consider a pulsating current with periods of 4A (on) and 0A (off) at a 50% duty cycle. The current averaged over time is 2A. By P = I^2 * R we see that power dissipation is 16 watts while the power is on. At a 50% duty cycle, power dissipation is 8 watts, twice as much as a constant current of 2A, even though the average current over time is still 2A. Your UPS draws a current that pulsates in time with the switching transistors, it does *not* draw a steady, constant current and this definitely does impact performance (voltage drop and power loss as heat higher than expected, battery life shorter than expected). Finally, as to heat issues, I run my APC Smart-UPS 750 on the 7.5AH internal battery paralleled with a pair of marine batteries (in series) of 115AH. Properly managed (turn off unnecessary lights, etc.) the unit will run for 18 to 24 hours. The transformer does get warm (temperature exceeds 80°C) without additional cooling. I put a 3-inch computer fan onto one of the case vents and as far as I can tell, even at high load the transformer temperature (external, measured on the iron core) never exceeds 40°C, generally doesn't exceed 30°C. That is quite acceptable and in my opinion active air cooling is highly effective at removing waste heat and keeping temperatures in check. Ideally, to minimize these issues, all of the wiring in the low voltage circuit should be replaced with 10 awg, and all blade/spade quick connects or other plugs should be removed and/or replaced with soldered connections, including soldering directly to the transformer's connection tabs. On my UPS the low voltage circuit contains exactly nine (9) connection points, each of which is a point of higher resistance and therefore voltage loss. Eliminating just two of these and replacing just the external feeders with 10 awg cut voltage drop by half and resulted in longer runtime and lower waste heat load. I will be replacing the rest of the wiring with 10awg this weekend. Easy to do and no reason not to.

Hello from Oklahoma-----Several years back, I did what you did by running two UPSs off of one car battery. Both UPSs operated on 12 volts so I got by with 1 battery. What I found out, and, what you are going to find out, is that the battery charging circuit in the UPS is not strong enough to keep a much larger battery charged. A trickle charger needs to be attached to the battery to maintain a charged up state so that when the power goes out, you will have a long run time. Yes, it will work for a while until the batteries go dead, which they will. In your case, with two 12 volt batteries, you need to put a charger on each one about once a week to maintain a charged up status. You can charge each one separately without removing the connector wire between your 2 batteries or removing any of the other battery wires.

Tq. Klau pkai batery long hours only apc hanya sepuluh jam tv boleh dihidupkan, kipas dan lampu. I try apc 1000w. My house no electricity supply i need lamp, fan and television. And small else.

Thanks for the video, I liked your idea and now plan to execute on my BR1000G. Its internal battery are dead. Will the current from APC be sufficient for charging high capacity batteries? Any limitations to consider while choosing the battery size?

Im wondering if it would work with thes new lifepo car batterys, that have build in bms ect,.

I did this on my tv and internet as well. I put a 12v 12ah battery on mine. Will run the tv and internet for well over 6 hours. It’s great and has been running for many years now.

But what about the charging function of the UPS now or has some bigger lumps to charge? Does it just take longer?

Nice work ,I have a very small MANHATTAN Battery backup do you thing your ideia will work with this one.its only a 5amp

I did this mod on what I can tell exactly the same UPS. One word of wisdom to share- do not put much load on it without also doing a fan mod. Mine overheated after around an hour, shut off and never worked again. I did not place more load on it than it was rated for, but I think the assumption by their engineers is that the duty cycle will be limited due to the limited duration of the included batteries.

Be careful of using flooded lead acid batteries due to off gassing.

I would assume you could run this set up with the battery bank connected to a solar array, basically just converting the ubs to an inverter with lots of outlets?

How did you deal with the battery constantly beeping after the power is disconnected from the UPS?

Excellent video. Subbed.

can you permanently leve the batteries hoock't up? like there were part of the ups?

Great video, great helper! Question, can you replace those lead acid batteries with the same value lithium iron phosphate batteries???

so the UPS will "learn" the new capacity of the larger battery on its own? or do you need to do a few charge/discharge cycles?

This is a good idea. I'll do this when the original batteries crap out.

when power goes out, can the APC heat sinks keep up if several devices draw power for an extended period? my understanding is they're solid heat sinks that don't radiate heat, so once they get hot they can catch fire if enough further time elapses

Excellent Video Mike. I know nothing about UPS devices but I had to purchase one recently for back up power on a home CCTV system. It was a good used one, apparently, but I have yet to get my head around how it functions etc. I suspect the batteries will need replacing as the old owner reckons he's had it for around 4 years or so, so that would tell me that the battery life cycle is almost due. It's an APC C1500 model, the one with the LCD display. Not sure what Ah sized batteries it contains, but I'd love to upgrade them if possible. Hopefully I can find the same physical sized batteries but with a higher output. I'll have to do more research on this. Thanks for the video. It's opened my mind about battery expansion.

i did this in 1995 in the Virgin Islands. two car batteries. . ran tv and stereo for weeks. got from offices old UPS systems whose batteries did not hold enough charge,.. new car batteries did it all. actually older boat batteries.

well how did you install the 10 amp inline fuse?????

two questions: the first is about running your electronics off a modified sine Wave inverter and second, have you increased the cooling or current carrying capacity ie swap out the MOSFETs etc? These units have a pretty short duty cycle unless the board can be populated with transistors to add capacity. many of these units all have the same circuit boards, just increased capacity with changes to the output stage.

Awesome & Thanks :)

What you did can be very dangerous depending on the UPS model. Some UPSes do not isolate their circuitry from mains. Always check for this per UPS before attaching an external battery.

Can this also work on 12v 7ah UPS ?

The issue I see with this is that if the power goes out usually the node that supplies internet to your home goes out too since most of them aren't on battery backups. I have a 6 kilowatt Eaton 9PX 6K at home with 2 EBM's on it. There are 75 12 volt 5 Ah batteries in that sucker which can run my normal load of 1200 watts for about 4.5 hours. The issue is that our node isn't backed up at the ISP level so if the power goes out the internet goes with it regardless of what I can do in the home.

very good idea. My APC NS1250 battery needs to be changed. The cable connector has 3 slots. I wanted to use a 24V marine battery. Is it possible ?

I'd be more interested in running a forced air gas furnace for a couple days to keep the house warm during a power bkackout. Would there be any output capacity differences between the wet cell batteries vs. the SLA battery types??

Looks like a great idea thanks

how much time the batt last until they go off?

hello mike. great video but i have one slight problem. I have the same unit and have it set up the same way. I need something to last a long time to keep my coal stove running. I'm gone 10 hours a day and if the power goes out, the stove is out. so I wanted to see how long it would last on battery power. when i unplugged it from the wall it went to battery power. The time meter was at 55 minutes. after about an hour the meter went to 0 and the unit shut off. Had a volt meter on the battery;s and still showed 25.4 volts. put my battery charger on the battery's. it took only 5 minutes to bring the battery's back up to full charged. Turned unit back on and the meter said 0. So I put the original battery's back in the unit and let it charge. the next day I did the same routine to see how long it would last. It lasted about an hour, the battery meter counter went to 0 and the unit shut off.. I took the battery's out of the unit and tested with volt meter. Both battery's still were charged at 24 volts. My question is ,,,,, is that meter some kind of memory timer that will only let the unit operate for a certain amount of time and is there any way to reset it or shut it off.. Give it a try and see if this happens to yours. Any help would be a great help. Thanks Ed.

Where's exactly did you install the 10amp fuse?

How is the fuse incorporated

User's Comment: "Wow, this video got me thinking about the importance of having a backup power source, especially when camping in remote areas. Can anyone recommend a good portable power station?"Your Reply: Absolutely! When it comes to portable power stations for outdoor adventures, I highly recommend the Segway Portable PowerStation Cube Series. With its massive capacity, fast recharging, and waterproof technology, it's perfect for camping in remote areas. Plus, the Smart APP Control allows you to easily manage the power flow. Happy camping!

how are you dealing with the hydrogen gas from the charging of the batteries

Hello. I have the same apc as you and when I doubled the size of my battery amp hours, my apc will still shut off with the same amount if time used as before my upgrade. How did you trick your apc to stay on longer than it was programed to be on from the factory with a specific amount of load? Very frustrated because I didn't get any benefits of doubling my batterys

nice idea sir❤️❤️👍

I have 2kva at 1500watts Ups ,can i use 2x 12v,26ah battery,is it safe? Is it going to be enough to charger 2 or more batteries

How did you overcome problem with full charging higher capacity batteries? It needs 10% charging power from total capacity

im trying to find how much VA my UPS need but i cant find a good calculation. lets say my PC is using 200watt on 230volt and 1.26A. how long would a 1000VA UPS last?

you should add a mppt solar charger to keep the battery charged and it will help for a long downtime assist. if you try this you need to know the max charge and the base charge and use the max voltage for the battery balancing and the 13.6 for flout charge if you don't do this the ups will not like it

i forgot what you did, but for anyone interested or if you don't already know- marine deep cycles operate slightly differently than normal 12V lead acids or gels. should be 13.4V When fully charged if not damaged inside too much. or maybe 13.2/13.3 is perfect health usually. Having a health tester is a godsend. really let's you know what's going on under the hood so to speak. But hope your setup is working ok! It must have some intelligent charging going on. So that's good. Any old ups would not be recommended for just any marine battery. Although they may work, they might be damaged or unreliable or just not perform as well as they could. Just saying from experience lol. plus always make sure it's a True deep cycle. They are between a starting and deep cycle, lots of people don't realize but some aren't fully deep cycle. Great video boss xD

how much VA's i need in one UPS for one PC ( power supply 700w) + one monitor ?

I like your replacement battery idea. However, I think the battery wire gauge could stand to be a bit heavier if you plan on operating with close to a full load. Make sure you have an operating fan in your UPS as some models will only run for a short time before overheating.

So can we make some forever battery's...using that same set up but running the battery through a quincer instead of a doubler while funneling back into it self with an outlet to power lets say a fridge think about it...it should go smoothly and before any power outages you could help alot of people if you build a simple blue print to follow....just a thought

What I want to do is get the lead out and go with 12V 10Ah lithium phosphate with F2 connectors, any thoughts?

At work in the factory we use many electric fork trucks. When all of them are charging , it leaves the Sulphur and hydrogen rotten egg smell in the air. Consider how bad it would be in a small space like a basement. Ventilation of batteries is very important. Not only do they outgas while charging they also do it while discharging. I put mine outside with a means of heating them when temps drop below freezing. I charge mine 2 ways. I have a dedicated 24VDC plug in charger and also a 1200 watt solar panel array with a battery charge controller. If batteries still get low due to no power grid AND no sunshine for days , I also use a 4Kw generator to top them off if need be.

@annestywest7488 I bought a Cyberpower cp1500pfclcda 1500va 1000w sine wave battery back-up system it has 2 9AH batteries 24v so I added 2 100AH sealed lead acid batteries 24v but it can't see that I added more AH to it and at 207w it only runs 44 minutes then shuts off but the batteries are still at 24.5v when it cuts off. Can I hack the system to change the settings? Should I just buy a power inverter to run my things on?

Hi Mike, i'm gonna do the same thing with my old apc ups, the only point is the battery dimension and weight, unfortunatelly the only way to go is to use car batteries so i decided to use two of 100Ah so i should get enough power to keep my NAS up and running, i'm also thinking to add a solar panel to charge the batteries, so it will become a double UPS-Powebank project, great video!

Yup, go good project to work on. But if possible, try to find an inverter that runs off of 48 volts as they run more efficiently and this is one I would like to use to run my gas furnace on. My problem is trying to find true deep cycle batteries that I dont have to take out a mortgage on.

Huawei, Santak, APC, Eaton, Delta series UPS products are available from stock.

My question can I add solar control to charge batteries

Did you ever test the runtime?

"All night long and then some! " LOL

Hey i found this in the used market. APC Smart-UPS SC 1000VA and thinking of adding 2 of these (also used market but new i box) Fiamm 10-års blybatteri (lead-acid) 12FGL42 EAN 5710927030145 12v 42Ah total cost 200 usd this would in theory if your hack works for this setup be stronger then anything new i can buy. Would the combination work. it has 4 x 6v batteries in series by default as far as i can tell.

It will have a plug to connect extra battery right? Why he opened it and put some wires ?

I removed the internal battery and extended wires to fix a 12v 80 amp truck battery to my APS UPS. I find that there is no difference in the lasting time of the UPS when the power is not on! Do I connect an external charger to the big external battery?

Great work, however I have doubts on that ups to charge the batteries. It may take ages, have you tasted that yet? Anything above 20A battery will take longer.

My dream is to have enough battery backup to run anything in my home for 24 hours with no power. I don't live in California but I am always hearing about rolling blackouts over there because their grid is always overwhelmed. These devices would help in that situation! Also, APC makes a model that allows you to connect an additional battery pack, and it extends the run time of my TV and internet from 50 mins to 212 minutes! it is the same as adding two more of those 24V battery twin packs. but that expansion unit is $250. buy the batteries separately and do it yourself and it will cost a fraction of that with the same result.

Hello. Very good video. I have been thinking to do the same for my ups long time ago. The issue here is; 1) When the ups will be in battery mode, its inverter will starts to overheat. How much depends on the load that will be at the output. 2) If it works for a long time, or many hours then the mosfets is most likely to break down. The manufacturer has calculated a specific time based on the output load and the autonomy of the battery. If you go through this then it is most likely to burn the ups as well. In my opinion, if someone makes such a modification like this, to increase the amperage of the battery by almost twice and not more. For example, if it is 9Ah to go to 18, etc. This will make the inverter less likely to burn out.Again a very nice project, greetings from beautiful Greece!

Thumbs up for Alex !

The Back-UPS Pro 1500 supports an external battery pack, so it was designed to handle (12v 9ah x2)x3, that is 3 packs of 24v 9ah batteries, then it must run without issues with a 24v battery of 27ah or less.

Thanks for making this video, i was wondering why I was buying 5mins of backup power for $210....now i can run my gaming PC for two days..... Hooray!!!

Wife "Is that huge battery going to stay there?"

can you make a list and keen details of what materials did you use..(cause im not a techy person) i want to build this to backup my PC. ^_^ thanks!

I wondered about the possibility of doing something like this. I thought it was possible that the manufacturers might do something to prevent it., the way Canon has tried to prevent non Canon batteries from being used in their cameras. It's nice the UPS manufacturers haven't done something like that. I also wondered about the safety of using lead acid batteries in your house. Are there any issues with hydrogen outgassing that could catch on fire?

When figuring out how much power a device is drawing is VA important or just watts?

Thanks for the video, I was wondering, how safe is it to run a UPS for much longer than they are designed for? Don't they get very, very hot eventually as they are no fans?

look at the wall wart for your router... probably 12vdc output. You can just connect router direct to batt/delete the wall wart and save the loss through the inverter. Use the inverter for the T.V.

Do you worry about hydrogen gas generation as those are wet cell batteries?

Do this apc ups have a pure sine wave? 🤔

What about AGM batteries?

not all UPSs will work, some have a hard set run time limit before they will shut down regardless of how big your battery capacity is. (over heating protection as they don't have adequate cooling for heatsinks) out of interes what brand and model is your UPS unit? have a bank under my house consisting of 8 batteries, shoudl give a good run time ;) oh, also, deep cycle are a must standard car batteries are not designed to be drained and not be damaged.

Can i use it for my gaming pc ?

why did you put 24v if the initial battery replaced was 12v?

is that internal charger have enough capacity for those big batteries

I have. 8 varta bigblocks one of them have 12v 1015a starting current 240ah capacity. So little less than 1kah

I'm looking into doing a similar project as this but I'm not very familiar with battery specs... Here's my question, the APC uses a 12 volt battery. How is the APC compatible with 24 volts? It seems like the 24 volts would not work with the APC inverter. Could the APC over or under charge the 24 volt battery?