Home floor fans have a maximum power consumption of 50W. If they had a quarter kilowatts (250W), it would affect the family budget a lot. But otherwise good. :)
UPSes inverters are not meant to be used for more than few minutes, just enough time to shut the equipment off safely. They don't have fans for example, to keep the circuitry cool, and will constantly beep with no power going into them as they are designed. They are just not meant to be used like this. I recommend getting a commercial inverter instead that has proper cooling. It's not worth risking starting a fire. (or at a bare minimum add an intake fan to the UPS if nothing else)
Nothing will happen i am using old computer UPS as back up during power cuts since last 2 years . I made it with proper fittings of wires on walls and made a proper controlling junction. I use 4 Led tube lights each 18w. Since in city there is rare powwr cuts and during power cuts it can easily give backup for almost 2hrs 15minutes almost. That's enough for my second flat in my appt. 4rooms including hall area 😊😊😊😊😊
For anyone watching, if you plan to buy a UPS for this project i recommend you just go ahead and buy a real inverter. It will do a much better job and probably cost less than a UPS.
True in many cases, except one can often find a used UPS with a dead lead acid battery at a 2nd hand store for about $5 which is what I paid for one last time I went to Goodwill. Significantly cheaper than an inverter rated at the same wattage. Besides, a lot of people have old UPCs laying around at home with long dead batteries.
@@danielc9312 Well for 5 dollars that price its decent. I am not saying people should throw away a UPS if they already have a spare one. Just saying for me for example, used UPS is about 30 to 50 euros even with dead batteries. And those are the cheap UPS that are not rated to run over 30 minutes at a time. While for that amount of money i can buy a decent inverter thats new and can run for long periods of time.
At the beginning of this video I thought he would make a 12 volts solar lithium ion battery out of those 18650 cells, LoL! Tnx for the idea anyway, I'm planning to build that kind of setup and hoping to locally source a LiPo (Lithium Polymer) as a replacement for the lead acid battery, but I can't find a direct dealer with physical store here in my area in the Philippines
It’s better to buy 12 volt DC fan and light 💡 rather than stepping up voltage to 220 with an inverter . Your battery will drain so fast when you stepup to 220v AC for using normal equipment’s.
bro it is good idea to buy a cheap inverter instant of using old ups because there is a nasty secret in ups inverter design if you turn on the ups but without any load it still draws lot of power and waste lot of energy because now a days in all pc ups use 6v transformer with 12v battery for that higher inductance and lower resistance waste lot of energy but there are some advantage by this design you will get ton of juice from this tiny little transformer and cheap to manufacture but this is not suitable for solar application
Hey buddy! Please do an update video if ya ever decide to swap out the PWM charge controller with an MPPT version. Would be nice to hear the difference in system performance... Many thanks! 😎👍
So basically, you use the charge controller as a battery monitor. Just a note, any charge controller with USB outlets are cheapo crap, especially if considering adding a solar array. The UPS has its own internal charge controller. All you need to do is wire the bigger deep cycle battery to the +/_ terminals of the UPS, preferribly with a quick disconnect pigtail and an inline 10A fuse.
Hello may i ask how to connect wires if ever you plan to connect it to the direct electrical source then at the same time you can have the solar power for back up purposes.
What you have not tested is if you can use the UPS charging the battery at the same time as the solar charger, I mean if you could put both systems in competition, the electrical network and the solar panel at the same time charging the battery.
@@Lithium09 It only works for a while because the internal battery has a very small capacity. The time is limited only by the capacity of the battery, not by a timer that is not there.
A quote from someone that says. The Power of the sun in the palm of my hand. Or in this case a small table. Very nice very and build. One thing peope should watch out for is that your UPS can demand more current for power if the Charge controller can not handle that. It should be connected directly to batteries with a Fuse to protect it. Charge controller should really only charge batteries and not be use for to power up inverters or UPS. But other then that i love the build very simple and nice.
Most of UPS It will operate for just a certain time it is just a back up power for system unit purposes, I think it will run only for 5 or 20 mins.then beep alarm for cut off . How to reset the timer of UPS to continues operation as an off grid inverter? Thanks...
Theres no limit as long the volt 12, so you can have 50 12v batteries in parallel the only downside is the ups battery cables usually so tiny its dangerous to run high amps devices (microwave,motors)
I don't know if everyone here understands the difference between Amp hours, and amps. Amp hours are a measure of capacity. Yes, the UPS can have any capacity of battery as long as it remains 12 volts. True. But that does not mean the UPS can provide any amount of amps. These types of UPS are typically limited between 650 and 850 watts, or about 6 - 8 amps. The solar controller, in the same way, will be limited to a certain number of amps, usually listed on a sticker on the unit, generally 10 - 60 amps.
a quick question, I have this set up where am only using a UPS to charge the battery and also acting as an inverter, the problem is the UPS goes off after every 3 hours, and have to be there personally to turn it on again, even though I bought the controller to act as the charger, the question is how will I be able to bypass the 3-hour cutout on the UPS for 24-hour backup
The limit is probably due to a decrease in the capacity of the battery when taking off, or reaching the lowest charging current when charging the battery. The problem may be in the automatic charging ...
Your solar panel is not able to charge the battery at the same speed you are consuming power through inverter. Either reduce the devices or increase panel wattage
Bro hello. I have no car no battery and 220v 500 watt Power supply 40A 12v Can I connect it instead of the battery? Connect to the car inverter generate 220 volts?
Hi @HomeMade Creative I have solar tubular battery, So Can I connect to the UPS as you have shown, is there is any problem for the UPS for heavy load input, if I connect to the tubular battery 12 v
It can work indefinitely if you have good cooling. More expensive UPSs are designed to change 220V to 12V and then to 220V. These UPSs run continuously with the rectifier and inverter permanently. The cheaper type of UPS has a separate charging part and a separate part with the inverter. These can only be started with a voltage of 220V. With a small modification, it is possible to bypass the charging part and use only the inverter, which will work indefinitely (with cooling). For backup purposes (which you mention), the limit is a very small internal battery with a small capacity that can hold voltage and current for several minutes ...
bang saya mau tanya : 1. saya punya : - 1 buah aki 12v 100ah, - UPS 600va modif aki ext, - Controler +solar panel - Charger Aki portable 10A 2. PLN hanya hidup pada jam 18:00 sampai 6:00 (HANYA MALAM SAJA) 3, saya ingin menyalakan perangkat elektronik 100watt selama 24jam nonstop 4. bagaimana cara menyambung semuanya agar aki tetap tercarger (baik dari UPS modif, dari Solar Panel, dan dari Charger 10A : - siang hari aki tercharger oleh Solar Pannel - malam hari Aki tercharger oleh UPS modif dan Charger portable 10A
I have some questions, 1. Ups always have this constant beeping sound how do u cope with that? 2. ups are programmed to automatically turn off after some time, what can be done?
A lot of UPS come with a software to control it if you have a communication or USB port on the UPS. Try googling for ViewPower and download that, its software to control UPS where you can disable Beeping sound and change the automatic shut down. If you have a cheap UPS without a fan inside, i dont recommend to run the UPS more than 30 minutes because it will overheat. If you have a good UPS with a fan that cools down the transformer and components inside a UPS, then you can run that UPS for a long time.
So the UPS wasn’t broken? You just needed longer wire leads for power. And your using solar charge controller. Which means it no longer DIY cause 9.9/10 people do not have a solar charge controller laying around their basement. But OK!
There are two basic types of UPS. One type requires a 220V connection that closes the relay and recharges the battery with the inverter off. The 220V branch is continuous. In the event of a 220V failure, the battery circuit with the inverter is switched thanks to the capacitor and relay. Basically, this type of UPS can be started with a mains voltage of 220V. In order for it to work directly, it is necessary to bring 12V directly to the inverter (this was seen in the video). Another type of UPS constantly changes the input 220V to 12V and 12V to 220V to the output. The battery is an intermediate cell that charges and discharges as needed. This type works immediately after connecting 12V (does not require starting with mains voltage). This type does not have a 220V pass-through and if so, it is one marked output connection. This type does not require any intervention.
If only one fan or one 100 watt light runned with this ups what will be the the run time of backup time while charging the battery with 50 watt solar panel
It depends on the battery Ah. In this video the Battery used is 26Ah so usually the calculation is like this. 26Ah battery can supply upto 250w. It’s 26 x battery voltage x efficiency of battery. That gives u 26 x 12 x 0.8 = 249.6W. And if the battery is fully charged a 100 watt bulb can give u a backup upto 2.5hrs ideally. But there will be loss during conversation in the ups. We can consider 2 hrs as a backup. And for the 50w solar panel requires 4.5 to 5hrs to fully charge the 26Ah battery.
A standard 50W bulb should consume (take) I = P / U = 50/230 = 0.2A. The 12V 35Ah battery should provide a supply of 35Ah / 0.2A = 175 hours. The loss on the inverter can be over 20 percent - depending on the power consumption. The bulb should be lit for about 100 hours. Why does it only light for 10 minutes? Because you used an old battery that no longer has the capacity and doesn't hold the necessary volts for the inverter. Therefore, fully charging the battery will not help. Personally, I have an old UPS (170W) with a 12V 100Ah battery at home as an emergency power supply (the UPS does not require 220V for starting, so it does not have to be permanently in the mains). In the event of a power failure, I power the TV, LED lighting, notebook ... or compressor refrigerator, radio, LED lighting ... for several tens of hours.
Home floor fans have a maximum power consumption of 50W. If they had a quarter kilowatts (250W), it would affect the family budget a lot. But otherwise good. :)
I've learned lots of things 😊
Thanks sir ✌️
Install a small 12v fan inside the ups to keep the transformer and transistors cool as they are not designed to run for long time.
Sure
Doi fe delo que a dicho
UPSes inverters are not meant to be used for more than few minutes, just enough time to shut the equipment off safely. They don't have fans for example, to keep the circuitry cool, and will constantly beep with no power going into them as they are designed. They are just not meant to be used like this.
I recommend getting a commercial inverter instead that has proper cooling. It's not worth risking starting a fire. (or at a bare minimum add an intake fan to the UPS if nothing else)
Here is the Answer, ruclips.net/video/SVysRXpbJys/видео.html
ruclips.net/video/irtzGW9Uc3M/видео.html
Nothing will happen i am using old computer UPS as back up during power cuts since last 2 years . I made it with proper fittings of wires on walls and made a proper controlling junction. I use 4 Led tube lights each 18w. Since in city there is rare powwr cuts and during power cuts it can easily give backup for almost 2hrs 15minutes almost. That's enough for my second flat in my appt. 4rooms including hall area 😊😊😊😊😊
But you are also correct at your point of view 😊 solution is just add one mini (cpu exhaust fan) to keep transformer and transistors cool
Cleanest build of all time
Excellent... the simplicity is outstanding. Everyone's got an old UPS gathering dust somewhere! The possibilities are numerous!
Thankyou So Much
@@homemadecreativee
Is possible to connect big invertor battery like 100ah or 150ah lead acid Battery ?
@@Royd20 yes as long as it is 12V, more ah longer your run time!
Esto era lo que buscaba, Gracias...
Disconnecting the piezoelectric speaking in the UPS would be a plus. :)
Great videos still useful I was wondering why are the solar output on AC so limited still this day!!!!!
For anyone watching, if you plan to buy a UPS for this project i recommend you just go ahead and buy a real inverter. It will do a much better job and probably cost less than a UPS.
True in many cases, except one can often find a used UPS with a dead lead acid battery at a 2nd hand store for about $5 which is what I paid for one last time I went to Goodwill. Significantly cheaper than an inverter rated at the same wattage. Besides, a lot of people have old UPCs laying around at home with long dead batteries.
@@danielc9312 Well for 5 dollars that price its decent. I am not saying people should throw away a UPS if they already have a spare one. Just saying for me for example, used UPS is about 30 to 50 euros even with dead batteries. And those are the cheap UPS that are not rated to run over 30 minutes at a time. While for that amount of money i can buy a decent inverter thats new and can run for long periods of time.
Great ups keep switching of
Neat and clean setup.
However you need to add heatsinks and fans to ups otherwise it will not last.
Good creative work.
Great idea
At the beginning of this video I thought he would make a 12 volts solar lithium ion battery out of those 18650 cells, LoL! Tnx for the idea anyway, I'm planning to build that kind of setup and hoping to locally source a LiPo (Lithium Polymer) as a replacement for the lead acid battery, but I can't find a direct dealer with physical store here in my area in the Philippines
Always great builds!! You inspired me to make a manual insert ps4!
Thank you
It’s better to buy 12 volt DC fan and light 💡 rather than stepping up voltage to 220 with an inverter . Your battery will drain so fast when you stepup to 220v AC for using normal equipment’s.
good idea , i testing your system
Informative video
very good
apik weess 👍
Am gonna try this yep very sufficient
Nice 👌 idea
bro it is good idea to buy a cheap inverter instant of using old ups because there is a nasty secret in ups inverter design if you turn on the ups but without any load it still draws lot of power and waste lot of energy
because now a days in all pc ups use 6v transformer with 12v battery for that higher inductance and lower resistance waste lot of energy but there are some advantage by this design you will get ton of juice from this tiny little transformer and cheap to manufacture but this is not suitable for solar application
Good idea
✌
Gud experment 👍
i subscribed
💙💚bravo my frient keep your viewer's inspired 😎💚💚💙
👌👏
Hey buddy!
Please do an update video if ya ever decide to swap out the PWM charge controller with an MPPT version. Would be nice to hear the difference in system performance...
Many thanks! 😎👍
Thanks I will Try
I like it.
GREAT JOB
How about fuses, battery disconnect and solar disconnect devices
nice for jungle country's who has no electric.
Ups can connect to electricity when electricity available?
Good job
GREAT !
Can you still have the ups connect to the grid
So basically, you use the charge controller as a battery monitor. Just a note, any charge controller with USB outlets are cheapo crap, especially if considering adding a solar array.
The UPS has its own internal charge controller. All you need to do is wire the bigger deep cycle battery to the +/_ terminals of the UPS, preferribly with a quick disconnect pigtail and an inline 10A fuse.
Those cheap solar controllers regulate votkage and work great for single panel set ups.
Wow
Super idea
Thanks a lot
Good video
super
Good bro
Ye .. sem mene bhi mere Home 🏠 pe set Kiya hua he ..mene ups me car ki battery connect kiy hue he . 😎
Great
Call me please for more information
Hello may i ask how to connect wires if ever you plan to connect it to the direct electrical source then at the same time you can have the solar power for back up purposes.
You can't use bath at same time with this setup
Hola.vuantas hora puede usar sin que se caliente el ups
Super
nice Idea lods❤️❤️🙏👍
Good and appreciate this. Please can the ups still charge the the battery when there is electric supply through ups 13Amp plug?
Yes U Can Use, but only one option at a time, 13amp socket or solar charge
I like
Interesting. Ditch the music. In fact, don't ever play any music for any instructional videos.
What you have not tested is if you can use the UPS charging the battery at the same time as the solar charger, I mean if you could put both systems in competition, the electrical network and the solar panel at the same time charging the battery.
Nice solar system
Yes, thanks
Nice
God vedio bro
How long is the UPS will last?
👌🤗👍😊 Gut
Very good sir
Yo tengo una ups pero solo funciona 5 minutos y luego apaga de manera automática. Cómo se quita el temporizador. Gran vídeo. Gracias
No es posible. UPS es solamente para computadora. No puede usar como un inverter. No se funciona despues de 15 minutos.
@@Lithium09 It only works for a while because the internal battery has a very small capacity. The time is limited only by the capacity of the battery, not by a timer that is not there.
Don’t follow these tricks instead u will burn the circuits of ups
Just after half an hour
You are right
my build 800va ups
same pwm solar controller
120ah car battery
only use led bulb 10watt x2
it last for 12hour..
Ok felicita
Eye ups kitne time tak use kiye ja sakta hain?
La salida hacia el UPS debiste colocarle diodos.
How hours can you run this for 9 watt LED bulb and can o charge mobile phone
A quote from someone that says. The Power of the sun in the palm of my hand. Or in this case a small table.
Very nice very and build. One thing peope should watch out for is that your UPS can demand more current for power if the Charge controller can not handle that. It should be connected directly to batteries with a Fuse to protect it. Charge controller should really only charge batteries and not be use for to power up inverters or UPS. But other then that i love the build very simple and nice.
I have later connected ups directly to the battery
Thanks
HomeMade Creative nice.
Most of UPS It will operate for just a certain time it is just a back up power for system unit purposes, I think it will run only for 5 or 20 mins.then beep alarm for cut off . How to reset the timer of UPS to continues operation as an off grid inverter? Thanks...
I am uploading soon another version of this UPS, where I have removed the auto shut off
creatif 👍
Fan rotary mointion
Bhai ups ka main power point ko kat dala kya
hi Sir, have you tried commercializing this in your community? also, what's the maximum battery that can be paired with the 300W UPS inverter?
12V anyAH
Theres no limit as long the volt 12, so you can have 50 12v batteries in parallel the only downside is the ups battery cables usually so tiny its dangerous to run high amps devices (microwave,motors)
I don't know if everyone here understands the difference between Amp hours, and amps.
Amp hours are a measure of capacity. Yes, the UPS can have any capacity of battery as long as it remains 12 volts. True.
But that does not mean the UPS can provide any amount of amps. These types of UPS are typically limited between 650 and 850 watts, or about 6 - 8 amps.
The solar controller, in the same way, will be limited to a certain number of amps, usually listed on a sticker on the unit, generally 10 - 60 amps.
@@dexterjsullen,😮😮😮😮❤❤😅😅😢😮😢😢
Good g
Thanks
Love brother
Give me the link to buy the charging controller
This a brilliant idea! You should have tested the efficiency and find out if UPS is better than an power inverter.
Yes, you are right
70% + efficient
Good thing is most ups are pure or clean sine wave...issue is, they wont stop beeping
yes i know, but u can simply remove that
@@homemadecreativee how to remove and stop beeping? can i plug also the ups to 220v?
@@kuyajulz3638 just open it there is a little dark thing desolder it and ur done
@@kuyajulz3638 find the piezo buzzer inside the UPS and fill it with glue or unsolder it
a quick question, I have this set up where am only using a UPS to charge the battery and also acting as an inverter, the problem is the UPS goes off after every 3 hours, and have to be there personally to turn it on again, even though I bought the controller to act as the charger, the question is how will I be able to bypass the 3-hour cutout on the UPS for 24-hour backup
The limit is probably due to a decrease in the capacity of the battery when taking off, or reaching the lowest charging current when charging the battery. The problem may be in the automatic charging ...
Your solar panel is not able to charge the battery at the same speed you are consuming power through inverter. Either reduce the devices or increase panel wattage
Increase solar panel. Your solar charger is failing to charge.
Can you tell what yellow things in 4:07?
Bro what is this battery back up timing
Bro hello. I have no car no battery and 220v 500 watt Power supply 40A 12v Can I connect it instead of the battery? Connect to the car inverter generate 220 volts?
Hi @HomeMade Creative I have solar tubular battery, So Can I connect to the UPS as you have shown, is there is any problem for the UPS for heavy load input, if I connect to the tubular battery 12 v
You can use that battery but not recommended
Omg
How much cost 1/2 kw solar inverter system project
Bhai चार्जिंग time kitna lagta h
Weldon
How mach time for battery full
Are they pure sine wave when used with battery? And can it power a small fridge if connected with a big battery?
They Are Squre Wave, It can be connected to bigger Battery, It can power small fridge
i am alredy use this method .but no use. 10 min once ups auto shutdown .
if you do not give any load to ups. it will auto shut down. it require more than 50 watt load to keep on.
yeah that work but not for long period of time ,,UPS designe for backup only not for solar set up or long period of time
Exactly
It can work indefinitely if you have good cooling. More expensive UPSs are designed to change 220V to 12V and then to 220V. These UPSs run continuously with the rectifier and inverter permanently. The cheaper type of UPS has a separate charging part and a separate part with the inverter. These can only be started with a voltage of 220V. With a small modification, it is possible to bypass the charging part and use only the inverter, which will work indefinitely (with cooling). For backup purposes (which you mention), the limit is a very small internal battery with a small capacity that can hold voltage and current for several minutes ...
How to buy plz link dedo buy karne ka
Can we also use the ac supply to the ups to charge the buttery?
Yes
bang saya mau tanya :
1. saya punya :
- 1 buah aki 12v 100ah,
- UPS 600va modif aki ext,
- Controler +solar panel
- Charger Aki portable 10A
2. PLN hanya hidup pada jam 18:00 sampai 6:00 (HANYA MALAM SAJA)
3, saya ingin menyalakan perangkat elektronik 100watt selama 24jam nonstop
4. bagaimana cara menyambung semuanya agar aki tetap tercarger (baik dari UPS modif, dari Solar Panel, dan dari Charger 10A :
- siang hari aki tercharger oleh Solar Pannel
- malam hari Aki tercharger oleh UPS modif dan Charger portable 10A
Dada carent er point ta ki oi vabe thakbe na cete dite hobe
With Avasva plans doing something like that was easy.
Can i get your insta....
I have some questions,
1. Ups always have this constant beeping sound how do u cope with that?
2. ups are programmed to automatically turn off after some time, what can be done?
1. You can Remove Buzzer (Beeping Sound Speaker) From PCB
2. I have run MY UPS more than 3 Hours without any problem
@@homemadecreativee why u remove Buzzer/
A lot of UPS come with a software to control it if you have a communication or USB port on the UPS. Try googling for ViewPower and download that, its software to control UPS where you can disable Beeping sound and change the automatic shut down. If you have a cheap UPS without a fan inside, i dont recommend to run the UPS more than 30 minutes because it will overheat. If you have a good UPS with a fan that cools down the transformer and components inside a UPS, then you can run that UPS for a long time.
In this Ups , if you remove a resistor (my case it's "r19" ) the ups doesn't turn off when timer
So the UPS wasn’t broken? You just needed longer wire leads for power. And your using solar charge controller. Which means it no longer DIY cause 9.9/10 people do not have a solar charge controller laying around their basement. But OK!
There are two basic types of UPS. One type requires a 220V connection that closes the relay and recharges the battery with the inverter off. The 220V branch is continuous. In the event of a 220V failure, the battery circuit with the inverter is switched thanks to the capacitor and relay. Basically, this type of UPS can be started with a mains voltage of 220V. In order for it to work directly, it is necessary to bring 12V directly to the inverter (this was seen in the video). Another type of UPS constantly changes the input 220V to 12V and 12V to 220V to the output. The battery is an intermediate cell that charges and discharges as needed. This type works immediately after connecting 12V (does not require starting with mains voltage). This type does not have a 220V pass-through and if so, it is one marked output connection. This type does not require any intervention.
Without the controller, the solar panel could burn out. I recommend amateurs to buy a regulator that charges the battery well and protects the panel.
amazon - then diy
Bhai yhi sistam ke sath 50w ka solar rheg to nhi chalega 🤔🤔
Batana jarur
मस्त इंडिया
If only one fan or one 100 watt light runned with this ups what will be the the run time of backup time while charging the battery with 50 watt solar panel
It depends on the battery Ah. In this video the Battery used is 26Ah so usually the calculation is like this. 26Ah battery can supply upto 250w. It’s 26 x battery voltage x efficiency of battery. That gives u 26 x 12 x 0.8 = 249.6W. And if the battery is fully charged a 100 watt bulb can give u a backup upto 2.5hrs ideally. But there will be loss during conversation in the ups. We can consider 2 hrs as a backup. And for the 50w solar panel requires 4.5 to 5hrs to fully charge the 26Ah battery.
what is the best 4 slot charger to charger 18650 batteries? your one is Lii-500S correct ?
Yes Lii-500S is the best, I have both Lii-500 and Lii-500 I will upload the video soon
@@homemadecreativee XTAR DRAGON VP4 Plus Charger is the best I guess.
May Be, I Don,t Know About That, But from my Experience Liitokala Lii-500S Best Charger
@@homemadecreativee Thank you
Ok so the two black cables that you used is the cable that connects to main power point to use so I got you now ok cool
Yes
Even with a bigger battery ups will not handle even a load of 50watt bulb for more than 10min. I have tested the same with a 35ah automobile battery
A standard 50W bulb should consume (take) I = P / U = 50/230 = 0.2A. The 12V 35Ah battery should provide a supply of 35Ah / 0.2A = 175 hours. The loss on the inverter can be over 20 percent - depending on the power consumption. The bulb should be lit for about 100 hours. Why does it only light for 10 minutes? Because you used an old battery that no longer has the capacity and doesn't hold the necessary volts for the inverter. Therefore, fully charging the battery will not help. Personally, I have an old UPS (170W) with a 12V 100Ah battery at home as an emergency power supply (the UPS does not require 220V for starting, so it does not have to be permanently in the mains). In the event of a power failure, I power the TV, LED lighting, notebook ... or compressor refrigerator, radio, LED lighting ... for several tens of hours.
i have tested 80 watt load with 45 ah car battery - 3 hour backup. your ups is bad