Frequently asked Q&A

• How do I best use SUNBOX?
• Do I need to switch my SUNBOX on when the power fail?
• Why not just buy a petrol/diesel generator
• Can I use my SUNBOX in a room/apartment/house?
  
• How long will my SUNBOX run?
  
• How long will my SUNBOX take to fully recharge?
  
• What warranties are applicable on my SUNBOX
  
• Which inverter do I need?
• Why should I buy the SUNBOX rather than the SPARKBOX?
• I want the xxxBox but need something more/less/different
• How to mount my solar panel/s for maximum efficiency?
  
  

Do I need to switch my SUNBOX on when the power fails?

No.
The SUNBOX and SPARKBOX ranges have a built-in relay that will switch to the inverter in the event of a power outage.
Once the SUNBOX has been plugged into a wall socket and the inverter switched on it will automatically switch to the inverter in the event of a power failure and back to mains when power is restored.

Why not just buy a petrol/diesel generator?

One reason to avoid petrol generators is the noise level. A 3000 RPM - 5Kwh petrol generator is extremely noisy ranging from 58dB to 95dB under load (similar to a circular saw at 1m).
SUNBOX produces about 35dB under load (similar a small room fan at low speed at 1m) making it usable in most rooms.

A normal petrol powered generator can produce a number of times more colorless, odorless and tasteless poisonous carbon monoxide gas (CO) than a modern car making it life threatening if used in confined spaces.
SUNBOX produces a tiny amount of harmless Hydrogen gas (H) mostly when charging.
Ventilation and an extractor fan prevents any buildup of this gas within the container.

Most inexpensive generators are of the absolute minimum quality which the manufacturer can get by with and still rationalize the advertised output. Neither the voltage nor the frequency is stabilised very well.
SUNBOX has no mechanical generation parts and utilizes regulating circuitry to ensure stable power output.

Generators run on petrol or diesel and the longer you use the the more expensive it is.
SUNBOX recharges its batteries from the power grid or from the sun during power failures.

Important: We recognise that there are applications for which these battery and solar based system are impractical.
Appliances that require heating elements e.g. electric geysers, plate stoves, electric ovens and hairdryers normally require more power than can sustainably be provided by DC based systems.

Secondly, SUNBOX is limited by the amount of battery storage it accommodates. If you require power for 8 or more hours, multiple times a day a generator or a much larger DC/solar system will be required.

Can I use my SUNBOX in a room/apartment/house?

Yes!
There is no harmful exhaust gases and the SUNBOX is virtually silent, using only quiet built-in fans when in operation.

Back to top

How long will my SUNBOX run?

It depends on how many appliances you plug into it and how much power they are using.

Calculating Run Time

How long your appliances will operate from a particular battery is dependent on the appliance's power consumption in watts (or AC amps x 220V) and the battery capacity.

The following formula can be used to determine run time in most applications using a 12V battery or bank:

Example:

How long will my 100 watt TV run with Basic SPARKBOX (12V 204 Ah)?

The load is well within the inverter's maximum power rating, therefore the inverter itself will not limit the run time.
The deep-cycle batteries can be discharged to between 75% - 80% (It is however a standard recommendation to discharge batteries only to 50%)

Thus Basic SPARKBOX running at constant load of 500W will run approximately 3 hours (6 hours with SPARKBOX @ 500W)

The SUNBOX range includes solar panel(s) which will be able to recharge the batteries during sunshine hours, extending this runtime.

Some common appliance power usage

These figures are approximate representations. The actual power consumption of your appliances may vary from these figures. Check the power tags on the appliances.

Back to top

How long will my SPARKBOX take to fully recharge?

Recharge rates are based on the following formula: Charging time (hours) equals Battery Capacity (Ah) divided by Charger Capacity (A).
 The normally accepted standard for efficiency loss is 20%-30%

Basic SPARKBOX has 2 x 7.6A charger and 2 x 102Ah batteries

Since our batteries will only be discharged to around 75% (approx 150Ah) The charging time for this example is 153 Ah divided by 15A which equals 8 hours

A 2OA charger is available om request that will reduce recharging to 5-6 hours

What warranties are applicable on my SUNBOX?

As the SUNBOX is modular many components have a specific warranty connected to them.

Batteries - 1 to 2 year manufacturer's warranty depending on the brand (approximately 4-5 years life time depending on discharge cycles)
Solar panels - 5 year manufacturer's warranty (20 years life-time 80% yield)
Inverter - 1 year manufacturer's warranty
Charger - 2 year manufacturer's warranty
Controller - 1 year manufacturer's warranty

The internal components other than those listed above have a 1 year swap-out warranty.

Warranties will be void if:
Unit cases are opened by any person other than SUNBOX personnel.
Units are stored or moved on their side or upside down.
Units are exposed to excessive moisture or extreme environments.

Which Inverter do I need?

The question is whether you should get a true sine wave inverter (SUNBOX & SPARKBOX) or a modified sine inverter (Basic SUNBOX & Basic SPARKBOX).

A true sine inverter is one that will give you a nice pure and smooth sine wave current like the track of a swinging pendulum. This is going to be similar to the electric current that you would have at home when you plug into the electrical grid.

A "modified sine wave" inverter is less expensive, but it produces a distorted square waveform that resembles the track of a pendulum being slammed back and forth by hammers. In truth, it isn't a sine wave at all. The misleading term "modified sine wave" was invented by advertising people. Engineers prefer to call it "modified square wave."

The "modified sine wave" has noticeable effects on many electrical loads. It reduces the energy efficiency of motors and transformers by 10 to 20 percent. The wasted energy causes abnormal heat which reduces the performance of motors, transformers and other devices, including some appliances and computers. The choppy waveform confuses some digital timing devices.

About 5 percent of household appliances simply won't work on modified sine wave power at all. A buzz will be heard from the speakers of nearly every audio device. An annoying buzz will also be emitted by some fluorescent lights, ceiling fans, and transformers. Some microwave ovens buzz or produce less heat. Surge protectors may overheat and should not be used.

However for most small appliances, such as a medium TV, laptop or appliances that have a transformer e.g. cell phone charger or WIFI router, a modified sine inverter will be sufficient.

There are some items that will require a true sine inverter. Some of those items are oxygen concentrators, laser printers, electronic clocks and devices with variable speed motors.

Your next consideration will be how much power your appliances consumes (Watts). Consider what items you will be running and how many watts each item requires. You will need to also consider how many of them you will be running at once and how many plugs you need so that you can determine which inverter will be the best for your needs.
You do not want to overload your DC to AC inverter by plugging in too many high wattage items at once.

Back to top

Why should I buy SUNBOX rather than SPARKBOX?

The addition of the a solar panel/s gives the SUNBOX some valuable extra features.

First and foremost it adds an additional/complimentary way of re-charging the batteries.
While SUNBOX does have AC chargers, the panels allow re-charging from the sun as well as/instead charging of the power grid.
Charging from the solar panel/s reduces the charging time of the batteries which ultimately have an impact on electricity consumption and thus the cost of recharging.

The solar panel will continue to add power to the batteries even while the inverter is in use.
Depending on the amount of small appliances switched on, the solar panels might even be able to sustain the inverter without draining the batteries.

Sunbox however was designed as an entry system to solar integration and specifically for short term (load shedding) use. This means that the default panel(s) is(are) not capable of sustaining the full load capacity of the inverter on its own.
Additional panels and controllers can however easily be added to SUNBOX to enhance the recharge capability.

The solar panel/s will also maintain the batteries during periods where the system is unused and un-powered.
Disconnected batteries slowly lose charge over a period of time damaging the chemical and metal structure. The addition of the panel and controller will however maintain a 'float' charge to prevent damage.

I want the xxxBox but need something more/less/different

Custom build units and or changes to the default units are possible on request
The complexity of some changes and availability of components will however affect the cost and build time.

The following additions are available on request:
Additional Solar Panels
Custom build Solar Panel mounts (swivel and pedestal)
Integrating the system into your electric distribution board.

How to mount my Solar Panel/s for maximum efficiency?

Solar panels need the maximum amount of sunlight to produce the maximum amount of solar power. They need to be pointed in the direction that captures the most amount of sunlight.

The following is a guideline to assist the DIY solar panel installer.

If you live in the southern hemisphere, your panels should be pointed north. Most home owners with solar energy systems mount their panels in a fixed position, where the panels can be manually tilted as needed (for example, they can be adjusted seasonally). Here is how to calculate the best angle for your solar panels:

Angle

The quick and easy (but less effective) way: take your latitude and add 15 degrees for the winter, or subtract 15 degrees for the summer.

• For example: if your latitude is 40 degrees, the angle you want to tilt your panels in the winter is: 40 + 15 = 55 degrees.

  In the summer, it would be: 40 - 15 = 25 degrees.

• The better way (winter): in the winter months, when there's less sun, take your latitude, multiply it by 0.9, and then add 29 degrees.

  For example: if your latitude is 40 degrees, the angle you want to tilt your panels in the winter is: (40 * 0.9) + 29 = 65 degrees.

  This is about 10 degrees steeper than the "quick and easy" way! It's also more effective, because you want your panels to be directly facing the sun at mid-day during those short winter days.

• The better way (summer): take your latitude, multiply it by 0.9, and subtract 23.5 degrees.

  For example: if your latitude is 40 degrees, your panels should be tilted at: (40 * 0.9) - 23.5 = 12.5 degrees.

• The better way (spring & fall): take your latitude and subtract 2.5 degrees.

  For example: if your latitude is 40 degrees, the best tilt for your panels in the spring & fall is: 40 - 2.5 = 37.5 degrees.

• For example Johannesburg

On the 21st December, the sun will rise 103° east of due north and set 103° west of due north.

On the 21st March/21st September, the sun will rise 91° east of due north and set 91° west of due north.

On the 21st June, the sun will rise 79° east of due north and set 79° west of due north.

You don't necessarily have to adjust the tilt of your panels every season. If you find that the energy generated by your solar panels is sufficient for your winter energy needs -- assuming that your highest energy usage is in the winter -- you can just leave the panels in the same position.

Note that the fixed-mount solar panels will be  least efficient during the summer, spring and fall, when the sun moves across a large area of the sky.

Knowing how to figure the correct angle for solar panels can help you to generate the most energy from your solar powered system.

Of course, the correct angle for solar panels is for ideal locations -- but in the real world, we deal with trees & buildings that may shade the panels, or areas with lots of leaves, dust, or debris. You might need to adjust the angle a little bit to compensate for less-than-ideal conditions.

Tilt

The solar panels or solar collectors must be tilted from the horizontal to a degree equal to the latitude where they are installed, plus 15 degrees in the winter, or minus 15 degrees in the summer.

The winter season has the least sun available, so you want to make the most of it. The tilt should be designed so that the panel points directly to the sun at noon. To calculate the right angle, multiply the latitude by 0.9, and add 29 degrees. 

Note - If the installation does not allow tilt adjustments, it should be installed for the winter .

For example:

Johannesburg
Optimum Tilt of Solar Panels by Month

Figures shown in degrees from vertical

Winter   40° angle

Spring/Autumn   64° angle

Summer   88° angle

Back to top