Posted on Category:UPS

Understanding the Difference Between Pure Sine Wave and Modified Sine Wave Inverters

If you’re in the market for an inverter, you may have come across the terms “pure sine wave” and “modified sine wave.” But what exactly do these terms mean, and how do they differ from one another?

In simple terms, an inverter is a device that converts direct current (DC) electricity, which is the type of electricity stored in batteries, into alternating current (AC) electricity, which is the type of electricity that is used in your home or business. This is useful if you want to power your appliances or electronics using a DC power source, such as a solar panel or a battery.

Pure sine wave inverters are designed to produce AC electricity that is virtually identical to the AC electricity that you get from your power grid. The waveform of this electricity is a smooth, sinusoidal curve, which is why it’s called a “pure sine wave.”

Modified sine wave inverters, on the other hand, produce AC electricity that has a more choppy, triangular waveform. While this type of electricity is sufficient for most household appliances and electronics, it may not be suitable for certain types of equipment, such as certain medical devices, motors, or sensitive electronics.

“Sensitive electronics” refers to electronic devices that may be affected by the quality of the power they receive. These devices may include:

  • Medical devices: Some medical devices, such as certain types of defibrillators and respirators, may require a stable power source in order to function properly. These devices may not work properly with a modified sine wave inverter.
  • Motor-driven appliances: Appliances that have motors, such as refrigerators and washing machines, may run more efficiently with a pure sine wave inverter. Modified sine wave inverters may cause these appliances to run less efficiently and potentially shorten their lifespan.
  • Audio and video equipment: High-end audio and video equipment, such as amplifiers and HDTVs, may be sensitive to power fluctuations and may not perform optimally with a modified sine wave inverter.

On the other hand, many everyday household appliances and electronics, such as laptops, smartphones, and LED light bulbs, are not as sensitive to power quality and will work just fine with a modified sine wave inverter.

It’s important to consider the specific needs of your electronics and appliances when deciding between a pure sine wave inverter and a modified sine wave inverter. If you’re not sure which type of inverter is best for your needs, it’s always a good idea to consult the manufacturer’s recommendations or a qualified electrician.

So, which type of inverter should you choose? Here are a few things to consider:

  • Cost: Pure sine wave inverters are generally more expensive than modified sine wave inverters.
  • Compatibility: If you plan to use your inverter with sensitive electronics or equipment, a pure sine wave inverter is a better choice.
  • Power Quality: Pure sine wave inverters provide cleaner, more stable power, which may be important if you’re running sensitive equipment or if you’re sensitive to power fluctuations.

In summary, pure sine wave inverters offer the highest quality of power, but they come at a higher price point. Modified sine wave inverters are a more affordable option, but they may not be suitable for all types of equipment. Ultimately, the choice between a pure sine wave inverter and a modified sine wave inverter will depend on your specific needs and budget.

Posted on Categories:Batteries, Lithium

Why lithium batteries are the ideal choice for your alarm system.

There are a number of reasons why lithium (life4po) batteries are better for your home alarm system than their lead-acid counterparts.

Here are just a few:

1. Lithium batteries are lighter, making them easier to install and position within your alarm system.

2. Lithium batteries have a much longer lifespan than lead-acid batteries, meaning you won’t have to replace them as often.

3. Lithium batteries are less likely to leak than lead acid batteries, meaning there is less of a chance of damaging your alarm system.

4. Lithium batteries can withstand higher temperatures than lead acid batteries, making them less likely to fail in extreme heat or cold.

5. Lithium batteries have a higher power density than lead-acid batteries, meaning they can provide more power for your alarm system for a given size.

Overall, lithium batteries offer a number of advantages over lead-acid batteries for use in home alarm systems. Lithium is the way to go if you are looking for a reliable, long-lasting, and powerful battery for your alarm system.

The importance of using a lithium battery in your alarm system.

A lithium battery in an alarm panel as a backup solution is of vital importance in South Africa for several reasons;

Firstly, South Africa has a very high crime rate. This means that there is a greater likelihood that your home or business will be broken into, and your alarm system could be the only thing standing between the criminals and your valuables. Having a backup battery for your alarm panel ensures that even if the power goes out, your alarm will still be operational.

Secondly, South Africa faces electricity blackouts on a regular basis. This can be due to load shedding by the power utility companies, or simply because of power outages in certain areas. Either way, if your alarm system is running on mains power and the power goes out, your alarm will no longer be working. This could put you and your property at risk. However, if you have a backup battery for your alarm panel, you can rest assured that even if the power goes out, your alarm will still be functioning and keeping you safe.

In conclusion, there are many good reasons to install a lithium battery backup solution for your alarm system – especially if you live or work in South Africa where crime rates are high and electricity blackouts are commonplace.

Frequently Asked Questions about Lithium Batteries

Q: What is a lithium (Life4Po) battery?
A: A lithium battery, also known as a Life4Po battery, is a type of battery that offers a number of benefits for alarm systems. Lithium batteries are known for their high energy density, which means that they can power an alarm system for a longer period of time than other types of batteries. Additionally, lithium batteries are not susceptible to the “memory effect,” which can cause other types of batteries to lose their charge over time. Lithium batteries also have a lower self-discharge rate than other types of batteries, meaning that they will retain their charge for a longer period of time.

Q: What are some benefits of having a lithium battery in an alarm system?
A: The benefits of having a lithium battery in an alarm system include the battery’s long life, high energy density, and low self-discharge rate.

Q: How long do lithium batteries last in alarm systems?
A: Lithium batteries are known for their long life span. In most cases, a lithium battery will last between 5 and 10 years in an alarm system. If the power goes out, the battery will continue to power the alarm system. There is no need to change the battery in your alarm system unless it is not working properly. It is recommended that you test your alarm system monthly to ensure that it is working correctly.

Q: What happens if the power goes out and I have a lithium battery in my alarm system?
A: If the power goes out, your lithium battery will keep your alarm system functioning. You may need to replace the battery sooner than if you had a different type of battery in your system, but overall, a lithium battery is a good choice for an alarm system.

Q: How do lithium batteries compare to other types of batteries in terms of cost and performance?
A: Lithium batteries are typically more expensive than other types of batteries, but they also tend to perform better. Lithium batteries tend to last longer and hold a charge better than other types of batteries, making them a good choice for devices that are used frequently or for devices that require a lot of power.

A note about this article: This entire article was written by an AI program called GPT-3 ( using the OpenAI API ), how cool is that? Phrased differently, I did not write type a single word of this article it was all done by a digital robot.

Posted on Categories:Lithium, Power Bank, UPS

Charge your Wi-Fi Router & laptop using a Power Bank

It is possible to keep your Wi-Fi on during loadshedding using a power bank, chances are you have one laying around already. This solution won’t be as elegant as using the UltraLan DC to DC Mircro UPS or the Ellies Cube, but it is certainly a good option especially if you have a power bank already and is keen to do some DIY.

Powering your WI-FI (keep your internet on during loadshedding) using a power bank

The concept is simple, you use a DC buck-boost converter (Chopper) to increase the voltage of your power bank from 5V to 9V or 12V depending on what your Router requires. Your mileage may vary.

If you want a simpler solution then this DC UPS is the way to go and if you want to power your laptop then this Laptop Backup solution is a good option.

How to find out the voltage of your router?

Look on the bottom of your Power Supply, there will be a sticker on it showing the Voltage and Amps that you will need to power the router. Take note that the Amp rating on the power supply is often time overstated and the actual router uses much less, this will be important later.

Tenda AC WiFi Router Power Supply
Tenda Wi-Fi router PSU

In the example above our Tenda Wi-Fi router has a power supply rated for 12V and 1A, this means we will need to set our boost converter to output 12V.

What is a Buck-Boost Converter & how will it be used?

A buck-boost converter is commonly used to create a constant DC output voltage from a variable DC input voltage source. In simple terms, it allows you to get a higher voltage out than what you are putting in or a lower voltage than what you are putting in.

DC-DC Boost Buck Adjustable Step Up Step Down Automatic Converter XL6009 Module Suitable For Solar Panel
Buck Boost Converter

The one we will be using is a buck and a boost converter, it combines the functions of a buck converter (used for DC voltage step-down) and a boost converter (used for DC voltage step-up).

But you can also use a normal step-up boost converter like the XL6009E1 based module.

  • If you are in Cape Town and surrounding area then you can buy one from Netram: Netram boost converter
  • If you are in Johannesburg and surrounding areas then you can buy from DIY Electronics: Buck-Boost converter

How to connect the power bank to your router using the boost converter

  • You will need a USB cable that you can cut in half, then plug the USB cable into the power bank, and the other end solder it to the boost converter ( actually, solder it first, then plug it in, hehe ).
  • Connect a volt meter to the other end of the Boost Converter and then adjust the potentiometer (blue box with screw) until the volt meter shows 12V or however many volts your router requires. The potentiometer has multiple turns. So it may take a while before you have reached the desired voltage. The potentiometer can rotate about 25x from start to finish.
  • Connect a wire to the other side of the boost converter and then either to a barrel dc jack or use a wire with one soldered on already. Make sure to connect to the correct positive and negative outputs on the boost converter.
  • Plug in your router.
  • Bob is now your uncle.
Powering a WiFi router using a power bank and a buck boost converter

Additional note on buck-boost converters

You can’t beat basic physics. You can’t make energy from nothing. In a steady state, the power (energy per time) out of a converter can’t be more than the power you put in.

Power in this context is current times voltage. In common units, Watts = Volts x Amps. If you put 2A at 5V into a converter, it is getting (2 A) x (5 V) = 10 W in. If it were 100% efficient, that’s what it would put out. If it puts out 12 V, then the current would be (10 W) / (12 V) = 0.83 A.

Of course, there is no such converter that is 100% efficient. The actual efficiency tells you how much of the input power (which is the same as the output power at 100% efficiency) it actually puts out. Let’s say this converter is 85% efficient. That means it puts out (10 W) x (80%) = 8 W, and at 12 V that would be 0.66 A.

This is where that earlier point comes in, the PSU of the Tenda does show 12V 1A, however luckily for us the router rarely pulls 1A and is closer to 0.5A which makes this a potential solution to power your Wi-Fi router, but you will need to do the same for your fiber ONT if you have that. If you have an LTE router then this solution will be fine.

Physics also says you can’t just disappear energy either. So the remaining (10 W) – (8 W) = 8 W has to go somewhere. In the case of a boost converter like this, it goes to heat. The 85% efficient power converter takes 85% of the input power and transfers it to the output, and heats itself up with the remaining 15% of the input power.

Keeping your laptop powered during loadshedding using a power bank

You can use this exact same concept for your laptop, however, you will need a much more powerful power bank as we have seen using the example above, you will need at the very least a 50-watt power bank. We do have some in stock, but I would much rather suggest you buy the WINX 100W Laptop Backup solution, it comes with a cable of your choice that can plug into one of the following brands: Dell, Asus, Acer, HP, and Lenovo laptops.

Posted on Category:Batteries

How to calculate battery run time using watts

To calculate the run time of your Lithium or Lead-Acid battery you will need the following values:

  • Volts of the battery
  • Ah rating of the battery
  • Watts of the load
  • The battery’s depth of discharge (DoD: 1.25 = 80% used, 2 = 50% used, 3 = 33.3% used, 5 = 20% used )
  • The efficiency of the inverter (60% if you are using a UPS, 85% if you are using a good inverter)

The formula to calculate the battery run time is: ( Remember your BODMAS )

Volts of the battery x Ah rating of the battery / Watts of the load / The battery’s depth of discharge (DoD) x The efficiency of the inverter

Battery Run time = V X Ah / Watts / DoD X Efficiency

OR for easier reading (V x Ah x Efficiency) / (Watts x DoD)

(12 x 100 x 0.85 ) / ( 140 x 1.25 ) = 5.82

5.xx is decimal thus 5 hours and then you take the xx, and multiply it by 60 to get the minutes.
5 hours & 0.82 x 60 = 49.2 which is 49 minutes and 2 seconds.
5.82 = 5h49m Battery Run time

Lead Acid versus Lithium Runtime

Running the lead-acid battery to 50% repeatedly is risky and will tremendously shorten its lifespan, it is much safer to only use 30% of the battery. Lithium you can use 80%+ of the battery ( but we recommend 75% ).

Scenario 1: How long will a 12V 100Ah Lead Acid Battery + Inverter run a Samsung 55″ TV

Let’s assume it’s a Samsung QLED TV, that pulls around 140 watts, this becomes our load and we don’t want to use more than ±30% of the battery to prolong it.

12 x 100 / 140 / 3 x 0.85 = 2.42
(12 x 100 x 0.85 ) / ( 140 x 3 ) = 2.42

A 55″ Samsung QLED TV will run for 2 hours and 25 Minutes on a 100Ah Lead-Acid battery.

Scenario 2: How long will a 12V 100Ah Lithium (LiFePO4) Battery + Inverter run a Samsung 55″

We again assume it’s a Samsung QLED TV, that pulls around 140 watts, thus this becomes our load.

12 x 100 / 140 / 1.25 x 0.85 = 5.82
(12 x 100 x 0.85 ) / ( 140 x 1.25 ) = 5.82

A 55″ Samsung QLED TV will run for 5 hours and 49 Minutes on a 100Ah Lithium LiFePO4 battery.

Conclusion

From the above, we can see that not only will the Samsung TV run much longer on the lithium battery, but it will also be able to do so for far more cycles, running the lead-acid battery in the above scenario will last you 1 maybe 2 years if you are lucky, then you will need to fork out R2 600 again for a new battery.

Ergo: The “rands per cycle” cost is better on Lithium Batteries.

This is where LiFePO4 batteries absolutely shine, longevity as it works out cheaper in the long run. This is especially the case when you have a Paradox or ADT Alarm system, I am willing to bet you have replaced that battery this year already and you will do so again if we hit Stage 6 this year again.

However, if you replace that alarm battery with a 7Ah lithium battery it should last you years, because of the increased cycles and high DoD rate of the LiFePO4 batteries.

Common examples of battery times for various electronics

We will use 30% used for lead acid and 80% used for Lithium in the below examples to err on the side of caution.

The 24 Volt example uses 2 batteries in series, the Ah remains the same, but the voltage doubles, to calculate the Wh of the batteries you simply multiply the Voltage by the Ah;

V x Ah = Wh

Quick fact:

2 x 12v 100Ah lead acid batteries in parralel 

12v x 200Ah = 2400Wh = 2.4kWh

2 x 12V 100Ah lead-acid batteries in series

24v x 100Ah = 2400Wh = 2.4kWh 

55″ LED TV + DSTV Decoder + Soundbar ( 130 watts )

12 Volt System

12V 100Ah Lead Acid: (12 x 100 x 0.85 ) / ( 130 x 3 ) = 2.61 = 2h36m Battery Run time
12V 50Ah LiFePO4: (12 x 50 x 0.85 ) / ( 130 x 1.25 ) = 3.13 = 3h7m Battery Run time
12V 100Ah LiFePO4: (12 x 100 x 0.85 ) / ( 130 x 1.25 ) = 6.27 = 6h16m Battery Run time
12V 200Ah LiFePO4: (12 x 200 x 0.85 ) / ( 130 x 1.25 ) = 12.55 = 12h33m Battery Run time

24 Volt System

24V 100Ah Lead Acid: (24 x 100 x 0.85 ) / ( 130 x 3 ) = 5.23 = 5h13m Battery Run time
24V 50Ah LiFePO4: (24 x 50 x 0.85 ) / ( 130 x 1.25 ) = 6.27 = 6h16m Battery Run time
24V 100Ah LiFePO4: (24 x 100 x 0.85 ) / ( 130 x 1.25 ) = 12.55 = 12h33m Battery Run time

Desktop Computer PC + 24″ Monitor + Internet Router ( 240 watts )

12 Volt System

12V 100Ah Lead Acid: (12 x 100 x 0.85 ) / ( 240 x 3 ) = 1.41 = 1h24m Battery Run time
12V 50Ah LiFePO4: (12 x 50 x 0.85 ) / ( 240 x 1.25 ) = 1.70 = 1h42m Battery Run time
12V 100Ah LiFePO4: (12 x 100 x 0.85 ) / ( 240 x 1.25 ) = 3.40 = 3h24m Battery Run time
12V 200Ah LiFePO4: (12 x 200 x 0.85 ) / ( 240 x 1.25 ) = 6.80 = 6h48m Battery Run time

24 Volt System

24V 100Ah Lead Acid: (24 x 100 x 0.85 ) / ( 240 x 3 ) = 2.83 = 2h49m Battery Run time
24V 50Ah LiFePO4: (24 x 50 x 0.85 ) / ( 240 x 1.25 ) = 3.40 = 3h24m Battery Run time
24V 100Ah LiFePO4: (24 x 100 x 0.85 ) / ( 240 x 1.25 ) = 6.80 = 6h48m Battery Run time

Game Console ( Xbox / PlayStation ) + 55″ LED TV ( 300 watts)

12 Volt System

12V 100Ah Lead Acid: (12 x 100 x 0.85 ) / ( 300 x 3 ) = 1.13 = 1h7m Battery Run time
12V 50Ah LiFePO4: (12 x 50 x 0.85 ) / ( 300 x 1.25 ) = 1.36 = 1h21m Battery Run time
12V 100Ah LiFePO4: (12 x 100 x 0.85 ) / ( 300 x 1.25 ) = 2.72 = 2h43m Battery Run time
12V 200Ah LiFePO4: (12 x 200 x 0.85 ) / ( 300 x 1.25 ) = 5.44 = 5h26m Battery Run time

24 Volt System

24V 100Ah Lead Acid: (24 x 100 x 0.85 ) / ( 300 x 3 ) = 2.26 = 2h15m Battery Run time
24V 50Ah LiFePO4: (24 x 50 x 0.85 ) / ( 300 x 1.25 ) = 2.72 = 2h43m Battery Run time
24V 100Ah LiFePO4: (24 x 100 x 0.85 ) / ( 300 x 1.25 ) = 5.44 = 5h26m Battery Run time

A note on Depth of Discharge (DOD): This is very important!

DOD is a measure of how deeply a battery is discharged.

When a battery is 100% full, the DOD is 0%. The (Ah)Ampere hours removed from a fully charged cell or battery is expressed as a percentage of rated capacity.

For example, if 25 Ah are removed from a 100 Ah battery, its depth of discharge is 25% and the battery is at a 75% state of charge.

A note on Inverter Efficiency

In short, Efficiency is the ratio of the energy output of an appliance to the energy input, expressed as a percentage. Since appliances require more energy than they provide, some energy is lost. 

Sometimes bigger is not better. What we really need to know is what percentage of the power that goes into the inverter from the battery comes out the other side as AC power. To make this calculation even more difficult, the efficiency of an inverter changes with the output load placed on it. if a small load is put on an inverter it may be only around 50% efficient. However, increase the load to near the inverters stated maximum continuous load, and the efficiency will rise to around 90%.

A 3000 Watt inverter may draw around 20 Watts of power from the battery when it is connected and turned on without anything plugged into the output. This power is what the inverter needs to run itself… battery monitoring circuits, alarm circuits, and maybe a small fan.

Now if we plug in a small AC load… say 20 Watts… the total load on the battery is now 40 Watts (20W for the inverter + 20W for the load) so a bit of maths; 40 Watts in and 20 Watts out shows an efficiency of 50%.

Now if we look at this again with a small 150 Watt inverter – connected to the battery with no load it takes about 5 Watts to run the inverter. Now if we plug in the same 20 Watt load we have 5 Watts for the inverter plus 20 watts for the load giving a total load on the battery of 25 Watts. Thus 25 Watts in and 20 Watts out gives us an efficiency of around 80%.

That being said, when choosing an inverter, always go for a slightly higher output (watts) than you think you need. It is better to have a 1000-watt inverter running at 700 watts than a 700-watt inverter running flat-out!

As a rule, assume your inverter is only 80% to 85% efficient and work from there.

Note & Special Thanks: This article uses the wisdom of Dairyfarmer & Geoff.D on MyBroadband in the thread about Inverters and batteries.

Posted on Category:Lithium

Why are Lithium (LiFePO4) batteries better than lead-acid batteries?

But let me ask: What do you gain with a 12.8V 7Ah lithium battery? More cycles? Longer life span? Should be +- the same available energy?

Answer: To begin with, an SLA (lead-acid) battery and LiFePO4 battery of the same nominal Ah rating do not have the same usable energy capacity because the SLA will tolerate at best 50% depletion before the damage occurs and capacity reduces.

Lithium (LiFePO4) batteries will tolerate 80%+ depletion, the really good ones (cell phone batteries for example) can go as far as 97% before the built-in BMS shuts it down.

Paper spec-wise, conventional lead-acid batteries are only good for 100-200 max (as per spec) discharge cycles.

Realistically, once you flatten your gate/alarm SLA battery 10 times, its energy capacity drops to maybe 1/2, 1/3 of new.

Vicious circle: The lower the capacity, the more likely you are to flatten it again, more damage it takes.

Lithium has no significant capacity reduction even after 1000s of total depletion (90%+) cycles.

*The above is a slightly modified explanation originally offered by user fdlsys to a question asked by user leonsound on the AV Forum

Summarised

  • Usable capacity vs actual capacity (Realistically Lithium is about 80% to 90% usable vs 30% to 50% for Lead Acid)
  • Lifetime cycles ( Lithium lasts longer than lead-acid )

Charging Time & Loadshedding

Another practical example of why LiFePO4 batteries are better in the context of loadshedding is the charge rate. With the current loadshedding stages there just isn’t enough time between schedules to recharge lead-acid batteries.

Charging a lead-acid battery can take more than 10 hours, whereas lithium-ion batteries can take from 3 hours to as little as a few minutes to charge, depending on the size of the battery. LiFePO4 chemistries can accept a faster rate of current, charging quicker than batteries made with lead acid which makes them uniquely suited for our Eskom problem.

The lifespan of Lithium (LiFePO4) batteries over Lead Acid batteries

Finally, Lithium (LiFePO4) batteries are better able to sustain much deeper discharges than their lead-acid counterparts.

For example, if you discharge your lead acid battery to 50% or so routinely, that battery will likely give you around 100-500 cycles before it needs to get replaced & which is easily reached with Stage 4 loadshedding.

By comparison, a Lithium (LiFePO4) battery can be discharged down to even 20% and is said to deliver around 3000+ cycles. The extended lifespan of the lithium-ion battery, then, is significant making the long-term cost of LiFePO4 much less than lead-acid in the context of Eskom & regular Stage 2 to 6 power outages.

Posted on Categories:Lithium, UPS

Upgrade your UPS with a Securi-prod 7Ah Lithium Iron Phosphate Battery

Lithium powered UPS

Chances are you have an old UPS laying around which is no longer in use because the batteries inside are broken. Well, now you have a fantastic device to keep your TV or Router on during loadshedding by giving it new life using a Lithium battery.

This is a fantastic use case to give to your in-laws, to keep their internet on, a simple, easy, plug-n-play solution.

I replaced all our UPSes with lithium batteries & as a result, I can now power my Synology NAS during loadshedding.

This was an incredible discovery for me because I was always worried about the damage being done to my harddrives by Eskom by not having a backup solution for my Backup Drive Station. Some might not realise this, but a UPS is basically an inverter and charger, much like the ones everyone is currently buying all over the place.

A Mecer / Trolly Inverter will be able to handle a much larger battery like the 100Ah ones and their efficiency will be much better, but the UPSes you have at home or at the office can still be an incredible device if you pair it with a lithium battery, definitely an all-in-one device for your WiFi and Laptop to work from home during loadshedding.

This same principle can keep your internet on for at least 5 hours. I have a Mikrotik Router, Fiber ONT & a Wi-Fi 6 Router all powered by an old UPS I got off gumtree for a bargain, just by replacing its dated lead-acid battery with one of our Lithium batteries.

When the battery was put in the UPS it had a voltage reading of 13.45 volts, after running the Synology NAS at full power with 2 x 4TB harddrives for more than 2 hours, the voltage reading on the batteries was 12.64 volts, which means this set up should power our NAS for more than 3 hours.

If you cannot afford an Inverter Trolly or one of the DC to DC Inverters on Takealot, I highly recommend this cost-effective measure to power your internet. Especially useful if you have a UPS that takes two batteries.

If you do not have an old UPS laying around, ask your company for their old stock or look on Facebook Marketplace, people throw these units away because they think when the battery is dead it is no longer useful ( which in the days of lead-acid that was true, UPSes was not great at best ), which is not the case with the invention of these small factor drop-in replacement batteries designed to be used in hardware that used to run lead-acid.

Put new life into your old equipment, and make them more relevant today with loadshedding than ever before.

We do stock the 7Ah battery mentioned above if you are interested in doing the same conversion on your UPS. If you do not want to fiddle ( although this is straightforward), you can look at buying the all-in-one inverter which will power your TV during loadshedding.

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