Looking for a home UPS that is smart

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There is a quirk with the Cruze inverter. If the load drops below 200W, it thinks there is no load and does not come on (!)

There is no way to disable this behaviour. So if you want it work, load has to be above 200W

Makes me wonder what the minimum load is for inverters out there. Anyone done this test on their inverter ?

 

[6pack]

I didn't do any test but this happened recently a few days back. There was very low voltage < 50V coming to our building and the UPS came on around 3PM. I didn't run anything except router for 4 hrs and it did not shut down. Then ran the led lights and power saving bldc fan for another 12 hrs. Shut off the UPS at 7 in the morning. Its an 850VA UPS. shocking it ran for such a long time on a 150AH tubular battery. I'm guessing the bldc fan saved me a ton of battery power.

 

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I didn't do any test but this happened recently a few days back. There was very low voltage < 50V coming to our building and the UPS came on around 3PM. I didn't run anything except router for 4 hrs and it did not shut down. Then ran the led lights and power saving bldc fan for another 12 hrs. Shut off the UPS at 7 in the morning. Its an 850VA UPS. shocking it ran for such a long time on a 150AH tubular battery. I'm guessing the bldc fan saved me a ton of battery power.

This is the behaviour i expect from a UPS. I expect the UPS to work with just the router if that is all the load there is. Well, the Cruze won't run just a router. It will need some extra load. And that load must be at least 10% or more of its max capacity.

We are familiar with max loads but nothing is said about minimum load. To date i took it for granted that a 50W load say would automatically work.

A C20 150Ah is rated to deliver 7.5A for 20 hours. That is 90W for 20 hours. Brand new. No de-rating applies in this case. If you can keep your demand to that minuscule amount then great

 

[adder]

There is a quirk with the Cruze inverter. If the load drops below 200W, it thinks there is no load and does not come on (!)

There is no way to disable this behaviour. So if you want it work, load has to be above 200W

Makes me wonder what the minimum load is for inverters out there. Anyone done this test on their inverter ?

My Apc ups also runs with zero load, yet to connect my 5kw inverter, hope it runs with just the Apc ups, router, cordless phone connected, should consume about 100w combined, hope that is enough, In winter after 11pm there are not much load since fans are Off, fridge will not always be On.

So this 200w load you mention, is it in battery mode or in AC mains/bypass mode.

 

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My Apc ups also runs with zero load, yet to connect my 5kw inverter, hope it runs with just the Apc ups, router, cordless phone connected, should consume about 100w combined, hope that is enough, In winter after 11pm there are not much load since fans are Off, fridge will not always be On.

So this 200w load you mention, is it in battery mode or in AC mains/bypass mode.

In battery mode according to the video it was found with a 3.5kVA Cruze that the minimum load required is 280W or 10% of its max capacity.

Any load lower than 10% and this Cruze 3.5kVA UPS can't detect a load and shuts off. So no backup for loads lower than 280W.

I wonder if this is a quirk only with high capacity inverters. That is any inverter whose max load is lower than 1kVA should be ok.

 

[dpandey]

In battery mode according to the video it was found with a 3.5kVA Cruze that the minimum load required is 280W or 10% of its max capacity.

Any load lower than 10% and this Cruze 3.5kVA UPS can't detect a load and shuts off. So no backup for loads lower than 280W.

I wonder if this is a quirk only with high capacity inverters. That is any inverter whose max load is lower than 1kVA should be ok.

Does the load have to be resistive? Could adding a reactive load trick the inverter into running all the time?

 

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Does the load have to be resistive? Could adding a reactive load trick the inverter into running all the time?

He fixed it be attaching his 260L LG fridge. Otherwise he had to restart the inverter at regular intervals.

Don't think resisitive or reactive matters so long as the load is close to the minimum cut off point.

 

[NotMyRealName]

The single battery 12v inverters do not have any minimum load requirement. My 700va microtek powers one mobile charger if need be, and if that is off, the doorbell's pilot led. If even that is off, it still stays on, doing what i dunno...

 

[dpandey]

If connecting a fridge solved the problem, then the threshold is (in all prob) much lower. Fridges are idle most of the time.

Or maybe the inductive load of the voltage stab did the trick.

 

[rdst_1]

There is a quirk with the Cruze inverter. If the load drops below 200W, it thinks there is no load and does not come on (!)

There is no way to disable this behaviour. So if you want it work, load has to be above 200W

Makes me wonder what the minimum load is for inverters out there. Anyone done this test on their inverter ?

Is this tried and tested behaviour?
Or a one - off case that the company is giving bogus answers so they don't have to repair.

 

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Am thinking of a way to do capacity load testing.

- One idea is to get some two pin parallel adapters then put 100W bulbs in them and stick them in a power strip. Each power strip is a 400W load. Or just one like this Belkin at 800W

- Another idea is to get a space heater, this model has two settings 400W & 800W

Just let them run and time backup with nothing else on. Resistive loads are easier, they are constant. Attach a radio for sound and when things go silent we know when it cut off.

Repeat twice a year or longer to get an idea of capacity fade.

What concerns me with 100W bulbs x 4 on a power strip is the terminals can get quite hot so it might melt the power strip body if left for several hours and cause a short circuit. I need to test this with just one bulb and see how much heat the power strip can handle. Bulbs are easy to add and take away and allow more granular loads in multiples of 100W

Any other ideas ?

 

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Is this tried and tested behaviour?
Or a one - off case that the company is giving bogus answers so they don't have to repair.

What some guy found with the 3.5KVA cruze and made a video about.

The No load limit is programmed in so there is no way around without increasing the load past the cut off point.

In a way this reminds me of minimum acceptable water pressure when filling a washing machine, your fix if i recall was to restart the machine. Same here

 

[NotMyRealName]

If connecting a fridge solved the problem, then the threshold is (in all prob) much lower. Fridges are idle most of the time.

Or maybe the inductive load of the voltage stab did the trick.

just fyi, in cities like bombay, almost everybody runs fridges, acs etc without stabilisers.[DOUBLEPOST=1547137976][/DOUBLEPOST]Come to think of it, the power isn't all that clean. But i think it's enough so most people don't see the need for a stabiliser.

 

[dpandey]

From the video:

"you just need to give a 280 watt spike for few seconds within 11 hours in order to keep the inverter alive."

Doesn't sound too bad

 

[adder]

Am thinking of a way to do capacity load testing.

- One idea is to get some two pin parallel adapters then put 100W bulbs in them and stick them in a power strip. Each power strip is a 400W load. Or just one like this Belkin at 800W

- Another idea is to get a space heater, this model has two settings 400W & 800W

Just let them run and time backup with nothing else on. Resistive loads are easier, they are constant. Attach a radio for sound and when things go silent we know when it cut off.

Repeat twice a year or longer to get an idea of capacity fade.

What concerns me with 100W bulbs x 4 on a power strip is the terminals can get quite hot so it might melt the power strip body if left for several hours and cause a short circuit. I need to test this with just one bulb and see how much heat the power strip can handle. Bulbs are easy to add and take away and allow more granular loads in multiples of 100W

Any other ideas ?

The problem with adding that kind of unnecessary load or any load is that that will gulp the battery fast. On a two battery inverter you need 10amps or more/ hr to keep the inverter alive.
I guess for winter those room heater may be good idea, if one has the battery capacity.

Connecting a fridge won't solve the problem completly, since the compressor isn't On always neither is the heating coils for defrosting.

Guess I will add a air purifier and couple of external IP cameras to increase the load incase my inverter doze off.

Adding a timer switch with a load will also work, if one knows how long the inverter takes to detect a no load condition.

 

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The problem with adding that kind of unnecessary load or any load is that that will gulp the battery fast. On a two battery inverter you need 10amps or more/ hr to keep the inverter alive.

I mean just for a simple capacity test. How long does the battery last. Does it last as long as expected from calculations ?

Nothing to do with minimum load

I guess for winter those room heater may be good idea, if one has the battery capacity.

If i have 2.44kwh of lithium battery then can i expect around or close to 3h runtime with 800W load

Or how close does it come to 6h with 400W load

Lead acids will be different depending on how short the run time is

This article is interesting. Rule of thumb for figuring out a 'heavy load' is divide the Wh by 5. With the regalia that works out to 500W. Kinda low. Maybe this rule is only for flooded batteries.

For a 150AH flooded battery that is 360W. This is four times the C20 spec so should last 2.5h

Reading around that site i found something interesting

BLUNDER #3 Improper Watering
Flooded batteries require the addition of distilled water every two to six months depending on battery type, battery temperature, and on the charge controller settings and system usage. Some people forget to water their batteries. The photo shows a system that was ignored for more than two years. The low fluid level caused excessive gassing, and the plates to warp, short out, and spark, ultimately igniting an explosion.

At times i see people posting reviews of exploded flooded batteries. These guys evidently forgot to refill the battery and left it like that for a long time while still using it, then it exploded and now they blame the company

Guess I will add a air purifier and couple of external IP cameras to increase the load incase my inverter doze off.

You said something about a 5KVA inverter. Which one do you have

 

[adder]

I have https://www.amazon.in/Flin-Energy-F...RSTNQJ4VF7T&psc=1&refRID=YQJ7PQ2RYRSTNQJ4VF7T rebadged and sold in india under flin energy and various other names.

original taiwanese manufacture http://voltronicpower.com/en-US/Product/Detail/Axpert-VM-II-3KVA-5KVA

 

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I have https://www.amazon.in/Flin-Energy-F...RSTNQJ4VF7T&psc=1&refRID=YQJ7PQ2RYRSTNQJ4VF7T rebadged and sold in india under flin energy and various other names.

original taiwanese manufacture http://voltronicpower.com/en-US/Product/Detail/Axpert-VM-II-3KVA-5KVA

Was going to mention Flinn as the PC hookup does give it smarts. Software looks like it was written back in 2012. All wired. No wifi or phone hookup yet.

How do the costs work out ?

5kVA Flinn is 72k
4 x150Ah is another 60k

What about solar panels. Looking around, 1kW works out half a lakh so you would need 5kW or 2.5L

Total is almost 4 lakh ?

 

[adder]

Was going to mention Flinn as the PC hookup does give it smarts. Software looks like it was written back in 2012. All wired. No wifi or phone hookup yet.

How do the costs work out ?

5kVA Flinn is 72k
4 x150Ah is another 60k

What about solar panels. Looking around, 1kW works out half a lakh so you would need 5kW or 2.5L

Total is almost 4 lakh ?

5kva Flin was 65k after amazon cashback.
4 x 200ah 75k to 80k not yet purchased,designing and building a box to vent hydrogen.

panels not yet decided that's another 6 months to 1 year away. Assuming the rupee doesn't depreciate, the imported solar cells will drop by 5% in custom duties every year, currently 25% Anti dumping duties where added from last year, after protest from Indian cell makers( it seems we do have Indian cell makers but lagging behind in cell efficiency but its a start).

Was initially thinking of going 150ah but the charger as only 2A ,10A , 20A , 30A with 10A increment all the way up to 80A. I don't have a 15A option for the 150AH battery. Although exide solar battery brochure does mention a max C5 charge rate with C10 being the minimum charge rate.

Software is really old, most of these inverters require connectivity to Chinese servers for monitoring and many of times they are inaccessible due to ISP routing issues (xiaomi,Yi smart bulbs rarely work without VPN). I am only going to use the provided software for settings/configuration, not so much for monitoring. If I were to install a small mini Nuc or stick based computer or laptop, then I could use a android app to basically use the phone or tablet as a second screen, some even lets you control the pc.

As with most inverters it will show a inaccurate battery SOC because of lead acid battery, solely based on voltage and temperature and some guess work for the voltage sag under load.

So will use a dedicated wireless current/kw and battery monitoring devices which have there own screens and work without any internet. The only place that I will install them will be in the kitchen where mom or dad can know the load in kw before they turn On more appliances like a microwave or induction, (since with the 2kw water geyser running you are left with 3kw), during power out or when I install Solar panels.

All other app based ones will have connectivity issues unless some one from India starts making and selling them, for now all of the solar inverters are chinese rebadged except for luminous (only grid tied) and sukam as both off grid and grid tie but they need 8 batteries.

A really good accurate battery monitor with app costs $200+ https://www.amazon.com/Victron-BMV-702-Battery-Monitor/dp/B075RTSTKS?th=1
The above one will show the battery discharge in percentage and as well as Ah used.

 

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So what are the motivations here ?

Use solar during the day
Use solar to charge the batteries
Use the batteries at night

Is it worth it

How much would you save off the monthly bill.