UPS switches off way before battery is empty

Papa Smurf said:
i am very impressed by that 18aH battery lasting 2hrs on a load :thumbsup:
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I think it was the low load that helped with the long runtime. I just tested the power draw with a Sonoff POW R2 and it shows that the load of the 55" LED TV is 28.58W on lowest brightness, 34.50W on medium and 46.42W on high. In test 1 I changed to the lower 28.58W load at around the 12 minute mark.

I have not calibrated the Sonoff, so I suspect that it might not be 100% accurate.

I still think that the UPS cut out due to an internal timer and not due to other factors. I am attributing the cutoff just before the 1 hour 59 minute mark, instead of the full 2 hours, to a clock/hertz 'issue'.

At this stage I am assuming that the battery bank is charged to 100% and will be conducting a second test run soon. I will be running at the lower brightness setting of the TV. I suspect the UPS will once again cut out at the same 1 hour 58 minutes xx seconds mark. Ambient temperature is about double the ambient temperature than the previous test though - hoping it won't impact things too much.
 
ld13 said:
I think it was the low load that helped with the long runtime. I just tested the power draw with a Sonoff POW R2 and it shows that the load of the 55" LED TV is 28.58W on lowest brightness, 34.50W on medium and 46.42W on high. In test 1 I changed to the lower 28.58W load at around the 12 minute mark.

I have not calibrated the Sonoff, so I suspect that it might not be 100% accurate.

I still think that the UPS cut out due to an internal timer and not due to other factors. I am attributing the cutoff just before the 1 hour 59 minute mark, instead of the full 2 hours, to a clock/hertz 'issue'.

At this stage I am assuming that the battery bank is charged to 100% and will be conducting a second test run soon. I will be running at the lower brightness setting of the TV. I suspect the UPS will once again cut out at the same 1 hour 58 minutes xx seconds mark. Ambient temperature is about double the ambient temperature than the previous test though - hoping it won't impact things too much.
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and now i am impressed at your low power consumption on a 55" telly. Wow :thumbsup:
 
I prefer APC stuff. The Mecer is a rebranded Chinese device. However, Mustek's after sales service is superb
 
Papa Smurf said:
and now i am impressed at your low power consumption on a 55" telly. Wow :thumbsup:
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I knew it was low, but did not know it was this low. Clamp meter is showing 0.12A, so the reported wattage seems about right. But will retest once I have replaced the batteries on the clamp meter.

chrisc said:
I prefer APC stuff. The Mecer is a rebranded Chinese device. However, Mustek's after sales service is superb
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Yep, also a fan of APC. They have served me well. Simply using this Mecer as a test - could not say no as it cost only R199. Also looking at getting a proper APC UPS for my PC and getting a few dedicated APC AVR's for the house to protect a few choice appliances like the TV or refrigerator. But must first check the peak load of the refrigerator etc...

Eish, am I seeing things or is W!=VA*PF?

20200202_163054.jpg
 
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ld13 said:
I knew it was low, but did not know it was this low. Clamp meter is showing 0.12A, so the reported wattage seems about right. But will retest once I have replaced the batteries on the clamp meter.



Yep, also a fan of APC. They have served me well. Simply using this Mecer as a test - could not say no as it cost only R199. Also looking at getting a proper APC UPS for my PC and getting a few dedicated APC AVR's for the house to protect a few choice appliances like the TV or refrigerator. But must first check the peak load of the refrigerator etc...

Eish, am I seeing things or is W!=VA*PF?
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erm wtf
 
ld13 said:
I knew it was low, but did not know it was this low. Clamp meter is showing 0.12A, so the reported wattage seems about right. But will retest once I have replaced the batteries on the clamp meter.



Yep, also a fan of APC. They have served me well. Simply using this Mecer as a test - could not say no as it cost only R199. Also looking at getting a proper APC UPS for my PC and getting a few dedicated APC AVR's for the house to protect a few choice appliances like the TV or refrigerator. But must first check the peak load of the refrigerator etc...

Eish, am I seeing things or is W!=VA*PF?

/snip
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what firmware version are you on?
 
Steamy Tom said:
what firmware version are you on?
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2.8.0 - Only opened the box this afternoon. Took 5 minutes to research the latest firmware and there seems to be issues with 3.3.1 - one of the comments claimed that 2.8.0 had less issues, incidentally.

If I had to hazard a guess, there is an issue with the amp reading. Had these readings on the TV, based on the brightness:
46.42W 229.71V 0.24A High
34.50W 229.36V 0.17A Medium
28.48W 229.64V 0.17A Low
 
ld13 said:
2.8.0 - Only opened the box this afternoon. Took 5 minutes to research the latest firmware and there seems to be issues with 3.3.1 - one of the comments claimed that 2.8.0 had less issues, incidentally.

If I had to hazard a guess, there is an issue with the amp reading. Had these readings on the TV, based on the brightness:
46.42W 229.71V 0.24A High
34.50W 229.36V 0.17A Medium
28.48W 229.64V 0.17A Low
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i would expect your 55" tv to use close to 75-125W to be honest, what does the sticker on the back say for W rating?
 
Steamy Tom said:
i would expect your 55" tv to use close to 75-125W to be honest, what does the sticker on the back say for W rating?
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Ditto, I used 70W in my rough calculations a few weeks ago, but the sticker shows 145W. I suspect that the sticker is the max it will ever use when everything is in use. So max brightness, dynamic colour on, active wifi usage, bluetooth on, max volume etc etc. In my use case I used the standard mode and almost the lowest brightness and an average volume with content served over a usb stick.

In any case. I did a known-load test to see how accurate the Sonoff is. Used a few 6W LED light bulbs since I could not find a 60/100W bulb in the house anymore, else I would've used those.

1x6W 05.73W 0.07A 222.91V
2x6W 11.72W 0.10A 223.04V
3x6W 17.78W 0.14A 224.75V
The Wattage seems to be in line while the Amp reading on the Sonoff is out.

I went back to the TV. Replaced the battery on the clamp meter and took a reading.
28.24W 0.17A 225.28V W/V=A=0,1254. Got 0.13/0.14A on the clamp meter.
46.76W 0.25A 225.82V W/V=A=0,2071. Got 0.20A on the clamp meter.
Added a 80W fan,
125.80W 0.57A 227.95V W/V=A=0,5519. Got 0.51A on the clamp meter.

I am happy with the wattage being reported by the sonoff. Seems to be accurate enough?

In any case, test 2 was completed. UPS switched itself off about 20 seconds after the 2 hour mark. Battery stood at the 12.21V mark just before it died. Was able to turn the UPS on again directly afterwards.
 
Well ever since load shedding became a regular thing, I had to think of something, other than re-inventing the wheel to keep at least my cctv cameras up and running, so I installed a mecer ups some time last year.

Did a few tests and can confirm the theory around the 2hr timer. It is very much the case. No matter how big or small the load, same result.

I thought to send mustek a email about this... but ah well. The 'computer store' bought it from, denies any issues of course :) But what they forgot the day I bought it they already mentioned one that was brought back because of 'some' issue.

The specific thing I like about it, other than annoying cut out 2hr thing, comparing the charger scheme against a australian branded one I have, well the australian one ruined many sla batteries so far. Currently working fixing that charger problem.

But long story short, yes, it has to be a timer issue.
 
muon said:
Well ever since load shedding became a regular thing, I had to think of something, other than re-inventing the wheel to keep at least my cctv cameras up and running, so I installed a mecer ups some time last year.

Did a few tests and can confirm the theory around the 2hr timer. It is very much the case. No matter how big or small the load, same result.

I thought to send mustek a email about this... but ah well. The 'computer store' bought it from, denies any issues of course :) But what they forgot the day I bought it they already mentioned one that was brought back because of 'some' issue.

The specific thing I like about it, other than annoying cut out 2hr thing, comparing the charger scheme against a australian branded one I have, well the australian one ruined many sla batteries so far. Currently working fixing that charger problem.

But long story short, yes, it has to be a timer issue.
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What would you say in the e mail? Because a UPS is not designed to be used as a backup so they will just tell you it's working as intended.
 
thechamp said:
What would you say in the e mail? Because a UPS is not designed to be used as a backup so they will just tell you it's working as intended.
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You forgot to add they will reply and say please look at our actual power backup solutions which costs north of R7500 easily. Nope. So I comtemplated what their reply would be, so yeah not going that alley.

What you also couldve said is, you get what you pay for. Which is true for 99% of the time.
 
muon said:
You forgot to add they will reply and say please look at our actual power backup solutions which costs north of R7500 easily. Nope. So I comtemplated what their reply would be, so yeah not going that alley.

What you also couldve said is, you get what you pay for. Which is true for 99% of the time.
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Lol. Why are you laughing? Are a you mustek employee? Or a engineer, and if so, not a wonderful one. What is a power backup system... technically? :) And by what big margin does the one system differ from the other? The concept is the same. Except for two versions. The conventional modified sine wave and the actual pure sine wave meant for ALL appliances, given it CAN handle the load.
 
thechamp said:
What would you say in the e mail? Because a UPS is not designed to be used as a backup so they will just tell you it's working as intended.
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That ^^^

A UPS is a short term thing so you can power off gracefully or keep things going till your actual backup kicks in.

They're not designed to run continuously, probably why they have a hard wired cut off...

You people are going to burn your house down jerry rigging a UPS to run stuff over loadshedding.
 
Dude.. relax. True, know that.

I got thechamps point loud and clear but just reminded him how thin the line is, between the differences. I am very aware of the design principle of the ups, but it doesnt change the fact its a spin off of something else.

Component deratings, cooling etc are obviously all things being considered. I am speaking light loads of what my idea is/was. The mustek thing has its design to no run for longer than 2 hrs. Its unfortunate, but needs to be accepted and will find a different way to accomplish my goal. Sometimes its just easier to take something off the shelf, and that didnt work. Well, at the price I am willing to pay.
 
muon said:
Dude.. relax. True, know that.

I got thechamps point loud and clear but just reminded him how thin the line is, between the differences. I am very aware of the design principle of the ups, but it doesnt change the fact its a spin off of something else.

Component deratings, cooling etc are obviously all things being considered. I am speaking light loads of what my idea is/was. The mustek thing has its design to no run for longer than 2 hrs. Its unfortunate, but needs to be accepted and will find a different way to accomplish my goal. Sometimes its just easier to take something off the shelf, and that didnt work. Well, at the price I am willing to pay.
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Would it not run longer than two hours even if you fitted a bigger battery?
 
muon said:
Totally. No matter what the size battery.
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It certainly is a Mustek thing, my APC ran for 15 minutes on an 18AH battery, I fitted a 105AH and it ran forever during loadshedding, it was silent and way more efficient than the Ellies inverter.

I never burnt the house down by the way, it ran for years like that until it suddenly couldn't switch back to mains after one load shedding episode, it was the best R100 I ever spent.
 
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APC is quite pricey, but I'm willing to consider it... but (dumb question here) the nice thing about the mustek/mecer/rct/whatever is that has a normal 3 pin socket on the back, so I can plug in a multiplug (and plug the router & lamp into that). If I went with APC, would I need to cut the plug off the multiplug and replace it with the kettle-type plug? Aren't those generally pre-moulded?
 
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