[karan0009]

Hi All,

I recently moved in to a new house & looking for a new Inverter + Battery. It's a 2 bhk apartment. Can someone please suggest me what kind of Inverter & Battery should I purchase? I have zero knowledge on this.

My primary requirements are 4 tube lights + 3 fans + 3 power sockets with a battery back up minimum 2-3 hours.

[RaceHorse]

Originally Posted by RaceHorse

I realized the risk of running them dry, I checked the circuitry it is fine. Also, I found the inverter is providing a few minutes of backup but due to the load getting turned off quickly.

Not to take a further risk I turned off the UPS mode. I hope I can live without the backup for a few days. Now Inverter is one of the items added in the list of things to be repaired after lockdown.

Thanks for all the advice.

Took the inverter battery to inverter shop, after keeping it for 3 days to fill acid and recharge, they concluded that one cell of the battery is gone kaput.

They offered me an exchange which I found reasonable and exchanged it for Amaron Tall Tubular battery.

This one has more capacity than the old model. It fitted perfectly in the Inverter casing. There was no space left for installing water level indicator so I removed it.

Now I added reminders in the calendar for regular topping up of distilled water for every 4 months.

[null]

I was looking at buying a new battery (have a new inverter which is not connected yet) and was considering the Luminous range with capacity of 150AH (for a 12v inverter).

There are 5-6 different variants of the tall tubular type itself and is confusing :
1. RC18000 - 36 months warranty
2. ILTT18000N - 42 months warranty
3. ILTT18048N
4. Lumious shakitman
5. Luminous Inverlast


Unable to make out what are the differences (other than the warranty period - ranging between 36 to 60 months).

what do you suggest? Or should I check the Amaran range as well?

I am hoping to pickup a new battery( i.e., without exchange) + trolley (typically ~Rs 1500) in the range of 12-15k (lower the better to be frank) and hence request your feedback.

Thanks,

[saket77]

My inverter battery is a 4 year old 150aH Exide invamore (a flop Exide model). Noticed from probably last 7-8 months that the inverter’s charging light keeps blinking always; meaning that the battery probably is always in charging mode. I spoke about this with the Exide dealer and he says that the inverter itself is fine and it’s the battery which has gone weak and this is why the charging is always on. I topped up the electrolyte last week and things were still fine. What happened next is the back up failed within seconds after a power cut. I checked and found that electrolyte level in all but one cell was very low! I topped the level again and charged the battery through the same inverter. The battery seems to be holding up little better and the electrolyte level also seems to be ok since last 3 days. Experts, What could be the problem?

[Thad E Ginathom]

We built a small room plus kitchen and bath on our terrace. Reasoning behind it is that we have nowhere to run from a single-floor house if it floods again. Also it will be my wife's 'den.' (Hey! I want one now!

Actually, as do all things that start with the idea of small, minimum, cheap, it developed into being what some places in the world would call a nice little "studio flat.".

I need an inverter for it. I also need an AC for it. I'm wondering... what would be the minimum solar set up for a 1 or 1.5 ton AC, plus tv, fridge, lights.

I have a doubt about how it would work. It should have a battery to cover short power cuts, but it would never be expected to power an AC machine from the battery.

How to think this through?

[prithm]

Originally Posted by karan0009

My primary requirements are 4 tube lights + 3 fans + 3 power sockets with a battery back up minimum 2-3 hours.

How long do you see power cut in your area ? If power supply is erratic and you want to run most important (Tube, Small TV, Laptop, Fan, Mobile charge) appliances, then go for 2 150 ah battery set up. One will also do, but just to be sure since you mentioned power sockets.

Calculate here : Luminous Calculator

Originally Posted by Thad E Ginathom

I need an inverter for it. I also need an AC for it. I'm wondering... what would be the minimum solar set up for a 1 or 1.5 ton AC, plus tv, fridge, lights.

I too have this idea, and for AC, Fridge (old type) solar set up is atleast 4 panels and minimum is 2 kva. I would rather go for a desert cooler or mini portable cooler than AC (since this is going to be your safe house) when it comes to saving power consumption during emergencies. If you have plans to use the rest of your terrace as solar farm (more the panels, better the charging efficiency). And you have an option to create a terrace garden / party spot if you consider using panels as your roof. I would suggest a hut type cause you will need access to clean the panels when they get dusty.

Calculate here : Luminous Calculator

Originally Posted by saket77

What could be the problem?

Similar issue that I reported sometime back. Sulphated cells was the suggestion from R2D2 san and desulphation was recommended. I saw a sinusoidal wave in the level of electrolyte in a single battery.

Originally Posted by null

I was looking at buying a new battery (have a new inverter which is not connected yet) and was considering the Luminous range with capacity of 150AH (for a 12v inverter).

Have been using RC18000 for sometime (2+ years), haven't had much issue. Easy on pocket too. I will not recommend it if you are planning to do some really heavy duty deep discharge work like using it during long power cuts (> 8 hours). I hope your inverter is Luminous too ? Cause Luminous recommend s using their inverter with their battery for optimum performance of their battery charging and management technology.

[Prowler]

Originally Posted by Thad E Ginathom

I need an inverter for it. I also need an AC for it. I'm wondering... what would be the minimum solar set up for a 1 or 1.5 ton AC, plus tv, fridge, lights.
How to think this through?

Wonderful - the idea of building a Studio atop your home.
If you consider 1.5 ton AC plus the usual load, you need at least a 3 KVA set up. But you can insulate your proposed room with insulating material like Polystyrene blocks amongst others, you could do with 1 ton inverter AC. So the set up can be about 2 KVA. I have seen in Valmiki nagar - an architect couple's home several years ago. It was high energy efficient with low electrical consumption.
With rising prices of electricity, we need to add insulation in our homes. ACs use up quite a bit of energy.

[DaptChatterjee]

Originally Posted by saket77

My inverter battery is a 4 year old 150aH Exide invamore (a flop Exide model). What happened next is the back up failed within seconds after a power cut. I checked and found that electrolyte level in all but one cell was very low! I topped the level again and charged the battery through the same inverter. The battery seems to be holding up little better and the electrolyte level also seems to be ok since last 3 days. Experts, What could be the problem?

Your battery is in it's fag end of life. 4 years of life is pretty decent. You may think about exchanging it for a new one before it turns 5.

Originally Posted by Thad E Ginathom

I need an inverter for it. I also need an AC for it. I'm wondering... what would be the minimum solar set up for a 1 or 1.5 ton AC, plus tv, fridge, lights.

How to think this through?

it would be best a have a set up synchronized with grid power. That way, you can make-up the deficit in power through grid and also sell surplus power when you don't need it. Also you'll have power during the nights.The local supplier's permission would be required for that.
The solar panel power ratings are in KWp (p for peak) which means it would supply that power only in the best of the conditions (clear sky, summer) for a few minutes a day. The placement of panels (facing south) and the spacing between them (shadow of one panel should not fall on other) is the key in extracting the full capacity. For your requirement, I would suggest 5KWp set up which would be 20 panels (250KWp) per panel), 80 square meter of roof-top place and roughly 4Lac rupees in investment.

To run AC on inverter, you'd need loads of batteries which then would need another AC to cool down. Better to have a small DG set of around 3KVA capacity.

[Thad E Ginathom]

Thanks! No intention of running AC on inverter/battery, that would be wildly expensive and impractical! Also, we already have 7kva generator (Honda). But would like solar to power AC during day, but also have small battery backup for small appliances.

[srini1785]

Originally Posted by Thad E Ginathom

.. But would like solar to power AC during day, but also have small battery backup for small appliances.

Solar may not have enough power to sustain an AC. At least, not long enough. Roof top solar are capable of producing around 400W (peak) while the least amount of energy that 0.8T AC needs is 812W/Hr. Simple math and 30Mins max is what you can get.

Of course , if you add panels , you may get a higher mileage. Not to forget that 0.8T AC in chennai is like , well , to put in the local language , showing torch to the sun.

P.S : All values lifted from Google.

[Holyghost]

Originally Posted by Thad E Ginathom

I need an inverter for it. I also need an AC for it. I'm wondering... what would be the minimum solar set up for a 1 or 1.5 ton AC, plus tv, fridge, lights.

I have a doubt about how it would work. It should have a battery to cover short power cuts, but it would never be expected to power an AC machine from the battery.

How to think this through?

If you want to run your AC on Solar power even during a power failure without using batteries, I doubt such a system is available off the shelf. The reason being the varying solar power generation every second and will not be able to sustain the steady power required for your compressor. Even on a bright sunny day, there will be some moving clouds that cast a shadow on your panels once in a while and the output suddenly drops by 80% whenever these clouds passes over your panels. In a day this happens 100s of times and I don't think any commercial AC can sustain such power fluctuations.
There are custom AC systems that run on DC power which can be connected to your solar, but they don't make any economic sense right now.

The simplest solution would be to go for Grid-Tie system with whatever KW capacity you can afford. The AC will still be running from the grid and will only work when you have grid power. When you do not have grid power, your AC will not work; even when you have super bright sunlight hitting your panels at max force, your AC wont work without grid.
In this setup, your AC power consumption would be offset by the electricity you export from the panels during day time. Since you already have an inverter, you will get power backup during grid outages from your batteries. You can also spend some additional amount to upgrade to a Hybrid Grid-Tie which can provide backup power from solar even during extended grid outages.

If you want the AC to work during power outages, You have 2 options.
Go for 3KW or more Off-Grid setup with just enough batteries to sustain atleast 30 mins of AC usage and this setup can run your ACs as long as you have enough sun light irrespective of the grid status. The fluctuations in solar power will be smoothened by the power from batteries and your AC will switch to grid power only when both solar and batteries are not available. However in this setup, you will be wasting a lot of solar energy unless you scale up your batteries to consume all the solar power produced in a day.

The second option (most efficient but expensive) will be to have a 5KW or more grid-Tie setup with a high end Hybrid grid-tie inverter which can support atleast 3KW continuous off-grid power. The cheaper Hybrid Grid-Tie inverters are usually limited to 1.5KW off-grid power which cannot support the demands of an AC. With this setup, your AC can be connected to the Inverter and it will work even during a grid outage as long as you have solar power. Just like in off-grid setup, the solar fluctuations will be managed by the off-grid batteries and you get the additional benefit of exporting the excess energy which can offset your consumption during nights. A 5KW setup will on an average produce 500 units of electricity per month. This will be an overkill for a small studio apartment, but since this will be an extension of your existing home, 500 units will be more than enough to bring down your electricity bills, provide backup power and run an AC exclusively from solar power.

[PGA]

Originally Posted by Thad E Ginathom

Thanks! No intention of running AC on inverter/battery, that would be wildly expensive and impractical! Also, we already have 7kva generator (Honda). But would like solar to power AC during day, but also have small battery backup for small appliances.

Originally Posted by Holyghost

If you want to run your AC on Solar power even during a power failure without using batteries, I doubt such a system is available off the shelf.

An electrical or control engineer may be able to explain this better but what I have learnt from the net and scanning local markets is that it is possible to run an AC from the solar power. The fluctuations in solar output can be managed using a Variable Frequency Drive(VFD). Its my understanding that present day inverter technology being used in ACs and refrigerators uses a VFD. Needless to say that one would need a DC/AC inverter and and a VFD, normally built into single unit. What I also understand that it is more efficient to use a three phase output from VFD though single phase outputs are available too, therefore one would need a three phase compressor in the AC, Kirloskar has a model in the market in 1.5 ton range, I have been told.

All this doesn't cost much, cost of compressor is almost the same as single phase and AC/DC inverter+VFD should also be in the range of 15-20k for a 3KW solar system.

[Thad E Ginathom]

Originally Posted by Holyghost

If you want to run your AC on Solar power even during a power failure without using batteries, I doubt such a system is available off the shelf. ... ...

Originally Posted by PGA

An electrical or control engineer may be able to explain this better ... ...

Thank you both for your considerable input.

Holyghost, nearing bedtime, I am going to have to reconsider your post with a fresher mind tomorrow. But I think that you have confirmed my thoughts.

Ultimately I would be interested in a grid-tie system. I haven't researched this much, yet, and the little that I have seen so far is not very optimistic about our TNEB being helpful with the necessary permissions and meters.

As I say, I'll read the posts again, but I think I'm asking too much, because what I imagine in my perfect world would be a hybrid-hybrid system!

And, although I did not mention it in the particular post, I am reminding myself that we have a generator. Whilst the cost per unit is high, it does not get used for many hours averaged over the year.

We could be self-sufficient with a small off-grid system for fan and lights. In a flood, we might have lost the generator --- but if I can find a way to move that up, then we could even have AC so long as we can buy the petrol.

Edit... just reading again and wondering...

Go for 3KW or more Off-Grid setup with just enough batteries to sustain at least 30 mins of AC usage and this setup can run your ACs as long as you have enough sun light irrespective of the grid status.

How many batteries would that take. I'm sure it would be too many! But I am not very good at those sums.
.

[Aroy]

For a guide on solar panels
https://www.luminousindia.com/solar-...-24v-poly.html

Here is my simplified calculations for solar power solution
1. 300W = 2.5 sq.m, so 3 KW = 25 sq.m and this is peak output.
2. 12V 150AH = 1.8KVAH, so ~ 2 batteries per 3KVAH (assuming losses all round)
3. As battery capacity is rated at 10 hours discharge, you need 20 batteries for 3KVA backup of 10 hours. For 5 hours it will be approximately 12 batteries, due to derating.

So now for a 3KVA solar system with 5 hours backup, you need :

1. 25 sq.m of panel space, or Rs.91,000/ as per luminous
2. 12 150AH batteries = 1,44,000/ at nominal cost of 12K per battery
3. 3 KVA solar charging/controller unit ~ 40K
4. 3 KVA UPS

So you will be touching 3lakhs with some change left over.

[Thad E Ginathom]

Originally Posted by Aroy

So you will be touching 3lakhs with some change left over.

Financially, if I forgot about other luxuries like camera lenses and travel (assuming that is even possible in the coming twelve months, that might even be doable.

Practically, I am not so sure. One problem is that, by just building our new room, we have put some of the terrace in shadow. I expected to have to move our solar water heater, which now has the room a few feet to the south of it. In practice, though, it still delivers more scalding-hot water than we can use. A solar panel is not going to be so forgiving. It also adds a very considerable amount of weight.

One day, though, I really intend to go for a 3kva or more system, if a survey shows that it would get enough sun, so all this advice is going to be very useful to me.

Added... Some of the prices here at Luminous are very interesting.