Pure Sine Wave or Square Wave?

[Dan Spinnover]

Nonsense!

Ours were always connected to the inverters/chargers and had a life span between 3 and 4 years.

Now with our solar system we'll get even more life out of them.

donP

That's been my experience. Your mileage may vary. Let me explain... or expound...

As mentioned, if the battery is weak/old, it will continually take a charge, because it continually loses it. In this way, it's 'on' 24/7. Also, if a person doesn't check and add water to the battery on a regular basis, that will make it get old quick as well.

With the invertor, we had astronomical electricity bills of 6000 pesos a month. Without it (we have good service now), it's down to 1500-2000 pesos as a regular bill.

 

[donP]

Lubrication Only

With the invertor, we had astronomical electricity bills of 6000 pesos a month.

We have never been on the grid, so never got electricity bills (but had relatively high diesel fuel costs).
Now, with our solar system, the 2 inverters and the batteries we produce more kWh's than we need; the 16 kW diesel generator is only run for lubrication every 2 months for 20 min.

donP

 

[windeguy]

In defense of Dan Spinnover, if you are in a place where you do not get sufficient grid (or alternate) power to fully charge your batteries and they are deeply discharged as much as twice per day, then the batteries might only last about one year before they become heavily sulphated and turn into space heaters. You will also never be able to "equalize" your batteries in such a situation. The deeper you discharge them, the less time they will last.

 

[donP]

The Fourth Set

... if you are in a place where you do not get sufficient grid (or alternate) power to fully charge your batteries and they are deeply discharged as much as twice per day, then the batteries might only last about one year before they become heavily sulphated and turn into space heaters. You will also never be able to "equalize" your batteries in such a situation. The deeper you discharge them, the less time they will last.

Our experience from the past, before we went solar:
Our battery bank (16 @ 225 Ah) was discharged daily down to about 25% of the batteries' capacity (sometimes even less) and then charged with the 16 kW-diesel for a total of 1:55 hrs. only (in 2 runs, mornings and evenings). This would not have them charged 100%.
We always had the Battery Type selector (DR3624) set at 1 (= 'Equalize 2') and would occasionally run the diesel longer for equalizing.

With this set up, the ...
- 1st battery bank ("Trace T-115") lasted 5 y 4 months (although this is not representative as the batteries were hardly used during their first year);
- 2nd battery bank lasted ("Trojan T-105") 3y 10 mths;
- 3rd battery bank lasted ("US Battery 2200") 3 y 1 mth;
- 4th battery bank ("Trojan T-105") has worked 3 y 5 mths so far and is going strong still (now with solar system; no more deep discharges).

donP

 

[windeguy]

Our experience from the past, before we went solar:
Our battery bank (16 @ 225 Ah) was discharged daily down to about 25% of the batteries' capacity (sometimes even less) and then charged with the 16 kW-diesel for a total of 1:55 hrs. only (in 2 runs, mornings and evenings). This would not have them charged100%.
We always had the Battery Type selector (DR3624) set at 1 (= 'Equalize 2').

With this set up, the ...
- 1st battery bank ("Trace T-115") lasted 5 y 4 months (although this is not representative as the batteries were hardly used during their first year);
- 2nd battery bank lasted ("Trojan T-105") 3y 10 mths;
- 3rd battery bank lasted ("US Battery 2200") 3 y 1 mth;
- 4th battery bank ("Trojan T-105") has worked 3 y 5 mths so far and is going strong still (now with solar system; no more deep discharges).

donP

And on your experience I had upped my charge rate beyond what is normally recommended (about 1/8th the bank size) to charge the batteries more quickly, but I still had short battery life. For me, "fast charging" proved problematic.

 

[amp]

Last question before I make a purchase.

I NEED my laptop to be powered and my modem to be powered for work. Those are the only necessities, all other items are luxury. With only those two items what wattage inverter would I need?

How would I set that up? I'm a complete novice at electricity.

 

[windeguy]

Last question before I make a purchase.

I NEED my laptop to be powered and my modem to be powered for work. Those are the only necessities, all other items are luxury. With only those two items what wattage inverter would I need?

How would I set that up? I'm a complete novice at electricity.

For powering only a modem and your laptop, you would need only the smallest inverter like a 1 KW 12 volt model with 2 6 volt deep cycle batteries.

 

[amp]

For powering only a modem and your laptop, you would need only the smallest inverter like a 1 KW 12 volt model with 2 6 volt deep cycle batteries.

Can I get away with one deep cycle since I'm not pulling so much power to keep the laptop charged and modem running or is two unavoidable?

 

[windeguy]

Can I get away with one deep cycle since I'm not pulling so much power to keep the laptop charged and modem running or is two unavoidable?

One deep cycle is only 6 volts and unless you find a 6 volt inverter, unlikely, you will need 2 batteries for a 12 volt inverter.

Now you could use one 12 volt car battery, but it won't last as long as 2 deep cycle batteries which are better suited to the purpose.

 

[amp]

One deep cycle is only 6 volts and unless you find a 6 volt inverter, unlikely, you will need 2 batteries for a 12 volt inverter.

Now you could use one 12 volt car battery, but it won't last as along.

Makes sense, 6 volts x 2 = 12 volts for 12 volt inverter. I'm learning little by little. Car battery will be drained in no time, probably after one long day of no power.

right click>open image in new tab I don't know why it wont show the whole image


That chart is helping me a lot in making my decision. I don't want to cut it short in case I do need something else powered and don't want to over-do it wasting money. I really don't use electricity for much other than the computer and modem though. I can go without a fan in the heat, don't need TV, fridge stays closed, microwave is a maybe, and that is about it for electrical devices.

 

[windeguy]

A good trade off is a 1.5 KW inverter and 4 batteries.

 

[amp]

A good trade off is a 1.5 KW inverter and 4 batteries.

I don't think I need that much. I live in Santiago proper in a decent area where the power goes out maybe two or three times a week, if even once. When it does go out it is out for a couple of hours and back.

The most the power has ever gone out was 4 times in a week. The longest it has ever been out is 8 hours and that was once. The usual is once a week for about four hours.

 

[windeguy]

I don't think I need that much. I live in Santiago proper in a decent area where the power goes out maybe two or three times a week, if even once. When it does go out it is out for a couple of hours and back.

The most the power has ever gone out was 4 times in a week. The longest it has ever been out is 8 hours and that was once. The usual is once a week for about four hours.

Megatone - Wave Lite IL1012C1ES

About as low as you can go.

 

[PeteyPablo]

I've owned a couple of each type, and currently have a pure sine wave.

A relatively minor point:

When the electricity goes off,

You probably won't notice with a pure sine wave, but you'll definitely know with a square wave.

Everything runs the same with the sine wave, but with a square wave, anything with a motor will give you a continuous "waawaawaawaawaawaa" sound.

It's probably my imagination, but I think the "switch over" is more noticeable with the square wave.

AGREED! The "waaaaaaa" sound drives me insane. There is a difference, maybe had I gone with pure sinewave I would not HATE inverters so much!

Hell yes you notice the switch over! All devices with electric motors start whining!!!!

 

[PeteyPablo]

What do you guys think about this:

Whistler Pro-1200W 1200 Watt Power Inverter : Amazon.com : Home Improvement

PowerDrive RPPD1000 1000-Watt DC to AC Power Inverter with USB Port and 2 AC Outlet : Amazon.com : Automotive


I have my wife telling me, "don't buy things they don't use in this country" about that inverter.

There are a few gotcha's with those type devices.

1) those devices are not meant for heavy duty use
2) they do not charge your battery, only deplete them
3) what is sold in the DR is otherwise known as a Grid Tie Inverter...that is what you want
4) if it is not specified, most inverters tend to be square wave inverters

And yes, most electronics and computers will work but expect strange behavior on occasion.

 

[windeguy]

Petey has it right. You need an inverter/charger.

 

[PeteyPablo]

I don't think I need that much. I live in Santiago proper in a decent area where the power goes out maybe two or three times a week, if even once. When it does go out it is out for a couple of hours and back.

The most the power has ever gone out was 4 times in a week. The longest it has ever been out is 8 hours and that was once. The usual is once a week for about four hours.

I'm thinking about Santiago for next place to stay, What side of town is that? I seriously need steady power!!

 

[fuchs4d]

Practical experiences

Square disadvantages:
- fences are noisy. At night you will notice when street power comes and goes.
- loading uninterruptle power supplies for computers (very small inverter of its own): draws your inverter batteries empty with only little charging to the tiny batterie. Technical explanation of why this is so was foundin old Trace manuals or google. Best do not feed this devices with the inverter.

Practical tips:
- get a device with battery voltage display, or connect a cheap meater (USD 8 item) permanently as a gauge, so you can always see how much power left.
- proper grounding: 2 copper bars sticked about 1 m to the ground. Only few people do this, but is highly recommended. Please google for what can happen when not grouded.
- Xantrex is the reference since the 90th, but others catched up and there are alternatives.
- In Sto. Dgo. near Parque indepencia is a street with some electronic importers side by side, where you can buy all elements to configure your own box just as you could with a deskop PC. If interested, could look up google maps to remember exact street name.
- To start motors like for fridges, calculate 3 times of the regular motor consumption.
- Minimum usable output for small house/appartment is 1.5KW.
- Verify diameter of battery jumper cables.


Alexander

 

[donluis99]

One deep cycle is only 6 volts and unless you find a 6 volt inverter, unlikely, you will need 2 batteries for a 12 volt inverter.

Now you could use one 12 volt car battery, but it won't last as long as 2 deep cycle batteries which are better suited to the purpose.

They do make and sell 12 VDC deep cycle batteries too!

 

[amp]

Don't mean to bump such an old topic but figured I'd update on what I went with.


We got a 1.5kw inverter with 2 Trojan red T-105s for 21,000 and 2 year warranty on parts and labor.