You can download the specs and manual for those at APC. They might be useful for the conversion.
A random thought on inverters.
I see inverters in the 1000w range selling for $250 and up, but I also see offices throwing these away because it's too much trouble to change the battery:
![Gas Audio equipment Gadget Composite material Personal computer hardware]()
A UPS is an inverter for all intents and purposes and a pair of them cost me exactly nothing.
Although they're designed to accept an internal battery, adapting one to an external battery should be child's play.
A UPS is an inverter for all intents and purposes and a pair of them cost me exactly nothing.
Although they're designed to accept an internal battery, adapting one to an external battery should be child's play.
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A UPS is an inverter for all intents and purposes and a pair of them cost me exactly nothing.
Although they're designed to accept an internal battery, adapting one to an external battery should be child's play.
Ok, kind of embarrassing, tbh, I have never seen or heard of a PC Inverter, and now a tad confused. I have several Inverters that I use to run electronics that run on AC and not DC. I own several UPS backup surge protectors, that differ in wattage that I use for my computer systems, plural. I cannot fathom how an inverter that switches from DC to AC to be plugged into the wall outlet to run a computer running off of AC that converts to DC internally via the Power Supply. Now a AC to DC Converter adapter to an inverter I understand.
What am I missing?
And by looking at that image it looks like a UPS backup with multiple outlets like the one that I own, just that it extends vertically vs. my horizontal UPS. With that said, yearly Black Friday sales you will always find these UPS backup surge protectors at 50%-80% off savings, which makes them far cheaper to replace the whole unit, than the battery.
The OP is saying a UPS contains an inverter inside of it. Just add a DC power source (either replace the internal battery or Rube Goldberg an external battery) and you've got AC power.
A UPS is just (essentially) a battery charger, a battery and an inverter. There's a bunch of UPS specific bells and whistles that might need to be dealt with but the price the OP paid makes it worth trying.
A UPS is just (essentially) a battery charger, a battery and an inverter. There's a bunch of UPS specific bells and whistles that might need to be dealt with but the price the OP paid makes it worth trying.
I own 3 UPS, it is the word 'inverter' that caused ambiguity. What you are calling an inverter I refer to as a converter, whereas the device that I plug into my vehicle cigarette lighter to run my AC devices is what I call an inverter.
From what I was informed converter is AC to DC and inverter being DC to AC. I have even made both from scratch along with bridge rectifiers and what not. It was just the terminology that got be bewildered. I should also note that I also saw the question in google about the difference between UPS and Inverter devices, indicating that there was indeed a difference.
Regardless, back to the OP, 'Yea if you are picking them up for free, it is a no brainer..."
Exactly!From what I was informed converter is AC to DC and inverter being DC to AC.
Inside the UPS units in the picture above is a 12 volt lead/acid battery. --Not a big one, only about 7Ah
In the event of a power outage, the unit switches to this battery as it's power source. 12 volts DC is used to produce 120 volts AC. (Which as you say, is the function of an inverter.) A very nice, pure sine wave too.
My thought is to adapt the unit to a much larger external battery.
In electronics there are dependent and independent power sources. In addition, there are heat limitations in electronical components including resistors. UPS are rated in wattage, as you probably already know, and for those that do not, P=VI where P is power using the measuring unit of Wattage (v=volts, I=current ~ amps. Using a high-powered battery could potentially cause an internal fire for doubling or tripling the amperage.My thought is to adapt the unit to a much larger external battery.
If it was designed specifically to handle the increase in amperage and temperature that would be different. This is in theory and not practice.
Simply hooking it up to a ginormous battery won't nuke the neighborhood. One needs current flow to create heat. So without a load, hooking up a UPS to a 50000Ah battery won't do anything in and of itself.
It's once you start to draw a load that's more than the electronics can handle will be the issue. If one is judicious about loads, using a larger battery merely increases the run time.
It's once you start to draw a load that's more than the electronics can handle will be the issue. If one is judicious about loads, using a larger battery merely increases the run time.
Only quoting this part as the other I have no disagreement with. UPS devices have a minimum load, some around 70+ watts before it will switch over to battery use when power is out. Some are designed to be able to handle a higher amp rated battery, but one would also need a higher rated battery charger, or wait a couple more days for the battery to be charged. Other's on the other hand, I am not sure of. If they only draw the electricity needed in the system, it should be no issue, again less your previous mentioning of not watching how much load you put on it to point that the battery can handle the load but not the UPS.If one is judicious about loads, using a larger battery merely increases the run time.
Either way, I really do love having my UPS systems, although in my current location I have only had 1 blackout in the past 25 years, I have had numerous electrical spikes that my UPS not only was able to handle, but also prevent my computer from turning off when the spike blew the other power strip, which is an added redundance, that my UPS is plugged in to.
Also nice to know that if there is a blackout, that I can charge my laptop, tablet and phone for an hour for extra prolonged battery life.
"What you are calling an inverter I refer to as a converter"
The battery charger is a converter, the 120v AC output comes from the inverter.
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If your relying on these being 'pure sine wave' you might want to check the manual. I'd be really surprised if they were.
The battery charger is a converter, the 120v AC output comes from the inverter.
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If your relying on these being 'pure sine wave' you might want to check the manual. I'd be really surprised if they were.
Good call out!If your relying on these being 'pure sine wave' you might want to check the manual. I'd be really surprised if they were.
Manual: https://download.schneider-electric...7W6QAS_R3_EN.pdf&p_Doc_Ref=SPD_EALN-7W6QAS_EN
Page 8: "On-battery Waveshape: Step-approximated sine-wave"
What's the Difference Between Pure Sine Wave and Simulated Sine Wave?
Shopping for a UPS? Two types exist—and their respective output waveforms do have an effect on the equipment they're backing up.
APC's model numbering system is a disaster, as they have a long history of making changes and sometimes even complete redesigns without changing the primary model designation. The manual linked to directly above, for example, is for the ~2013 redesign of the series.
My recommendation, for whatever (little) it's worth, is to check your output with a 'scope.
My recommendation, for whatever (little) it's worth, is to check your output with a 'scope.
Most of these old APC are pure sinewave and they have a big 50/60 Hz transformer inside.
If you're on a budget, then this is much better than nothing. Otherwise it's not worth the hassle. For 200 to 600$ you get nowadays a very nice chinese all in one inverter delivering 1-3kW. Combine this with a NEW LiFePo4 battery, and you are ready to make your own electricity for the next 10 years if you treat your battery nicely. LiFePo4 have 3000 to 5000 discharging cycles where you can draw 80% of their capacity. Compare this to the lead acid 19th century batteries which will be dead not reaching 1000 cycles of 60% discharge.
For computer backup these UPS are good, but they overheat if you use them on a huge battery for hours. They are made to run for 5 to 30 min max.
Also you can only charge lead acid batteries from them and you cannot hook up solar panels easily.
If you're on a budget, then this is much better than nothing. Otherwise it's not worth the hassle. For 200 to 600$ you get nowadays a very nice chinese all in one inverter delivering 1-3kW. Combine this with a NEW LiFePo4 battery, and you are ready to make your own electricity for the next 10 years if you treat your battery nicely. LiFePo4 have 3000 to 5000 discharging cycles where you can draw 80% of their capacity. Compare this to the lead acid 19th century batteries which will be dead not reaching 1000 cycles of 60% discharge.
For computer backup these UPS are good, but they overheat if you use them on a huge battery for hours. They are made to run for 5 to 30 min max.
Also you can only charge lead acid batteries from them and you cannot hook up solar panels easily.
Actually most aren't pure sine wave because they don't need to be. The kind of UPS we're talking about was designed to run PC's, routers, etc. those all run on 'rectified' DC.Most of these old APC are pure sinewave
The main thing a PC power supply or the wall wort on your laptop or router does with the AC from the UPS inverter is turn it back into DC (DC obviously doesn't have a "wave" of any kind) so the AC input wave form doesn't really matter.
UPS's that are meant to run specialized equipment or equipment with AC motors can take advantage of pure sine wave inverters but just about anything that converts the AC back to DC doesn't care.
Read carefully, I was talking about APC UPS. Not consumer crap. At least the models I own myself are sinewave, I have the 24V 600W and 48V 3kVA models. All with real transformers and all from the early 2000s like the ones in the picture.
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...and Read post #13
The APC UPS's in the picture (XS 1000's) are "Step-approximated sine-wave" NOT "pure sign wave". Damn few UPS's in this class, especially the older ones, are pure sine wave. ...because there's no need for them to be pure sine wave.
Also, transformers don't convert AC to DC they only change the voltage. The rectifier is what 'rectifies' AC to DC.
...and Read post #13
The APC UPS's in the picture (XS 1000's) are "Step-approximated sine-wave" NOT "pure sign wave". Damn few UPS's in this class, especially the older ones, are pure sine wave. ...because there's no need for them to be pure sine wave.
Also, transformers don't convert AC to DC they only change the voltage. The rectifier is what 'rectifies' AC to DC.
I agree, the UPS from post 1 are not sine wave:
page 8
they weigh only 10kg each, most likely they have a high frequency transformer.
However the better models from APC, with approximately the same power, weigh more than double and they have a big transformer with iron core.
This type of transformer can only be used with low frequency, otherwise the core saturates.
Therefore the presence of a transformer with a lot of copper and iron is in nearly all cases an indication of sine wave output.
This also applies for solar inverters.
The advantage of these inverters is that you can start loads like motors easier, than with inverters with high frequency transformers.
Where a high frequency 1kW inverter might have problems to start a fridge compressor, the low frequency transformer inverter will do the job.
page 8
they weigh only 10kg each, most likely they have a high frequency transformer.
However the better models from APC, with approximately the same power, weigh more than double and they have a big transformer with iron core.
This type of transformer can only be used with low frequency, otherwise the core saturates.
Therefore the presence of a transformer with a lot of copper and iron is in nearly all cases an indication of sine wave output.
This also applies for solar inverters.
The advantage of these inverters is that you can start loads like motors easier, than with inverters with high frequency transformers.
Where a high frequency 1kW inverter might have problems to start a fridge compressor, the low frequency transformer inverter will do the job.
Some may, but you said "most", and that's simply not the case. Best not to lead people to believe things that aren't true, and potentially harmful to their equipment.I agree, the UPS from post 1 are not sine wave:
page 8
they weigh only 10kg each, most likely they have a high frequency transformer.
However the better models from APC, with approximately the same power, weigh more than double and they have a big transformer with iron core.
This type of transformer can only be used with low frequency, otherwise the core saturates.
Therefore the presence of a transformer with a lot of copper and iron is in nearly all cases an indication of sine wave output.
This also applies for solar inverters.
The advantage of these inverters is that you can start loads like motors easier, than with inverters with high frequency transformers.
Where a high frequency 1kW inverter might have problems to start a fridge compressor, the low frequency transformer inverter will do the job.
1 - 20 of 20 Posts
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