Solar lamp, what to choose ?

Lighting is the first application of solar energy in South countrises. However, solar lamps available on the market are not always good. Here are the keys to make the good choice.

A solar lamp is autonomous and composed by a bulb, a battery and a small solar panel. Do not confuse them with simple bulbs which work with 12V DC or with a solar lampfo public lighting or with garden lamps. Solar lamps can be used when you want, where you want, and are transportable.

How to choose his solar lamp ?

To choose a solar lamp, you must discern its components : panel to produce energy, battery to store it, the bulb and the box integrating all the housing.

It must be balanced between the panel size, the bulb power, and the battery capacity. The panel must be able to charge several hours of the bulb consumption per day. The battery mus be size enough to store the energy of the day and work all the night. Solar lamps characteristics are writing on themselves, note well.

Example :

  1. A 2W panel will run in mac power about 5h per day so it will produce 2Wx5h=10W
  2. A 6V, 2Ah battery can store 6Vx2Ah=12Wh
  3. A 3W bulb will use this energy and it will work during : 12Wh/3W=4h

Now you know how work a solar lamp.

How to be sure of its life durability ?

Nothing is eternal. One day, you will need to replace one of the components, probably the battery and maybe the bulb. So prefer the devices you can find in the commerce.

The solar panel

It must be a good quality and rainproof. The power and the tension are written on the back of the panel. The deported models, with a cordon, are convenient to keep the lamp away from sunlight and the thieves during charging. With these models, you can also change the orientation of the panel to follow the sun's path from the morning to the night. You can earn 50% energy, it is good for less sunny days. You must know that amourphous solar panels are bigger for the same power but work better during overcast days and in the shade. To finish, a little LED indicator to know when the solar panel is charging the battery is welcome.

The battery

It must be a sealed model for reasons of mobility. If it is composed of several cells in series, make sure the voltage is standard and you can get by putting other cells in series (a multiple of 1.5 is desirable).

L'ampoule

The type of bulb plays an important role. For a long time, the mini compact fluorescent tubes dominated the market, but they are gradually being relplaced by Light Emitting Diodes (LEDs). If they are much better in the field of consumption and longevity, their light is almost all the time wan and disaster, but also much less diffuse. So we can find on models with LED some reflective mirrors. Examine the quality of these mirrors to see how they will stand the rest of time. For example, simple reflective tapes may come off.

A model with compact fluorescent lamp (bulb type economic) will have more diffuse and warmer, generally more pleasant, light. The Achille's heel of this type of bulb is a limited lifespan, so it is interesting to relace the bulb easily when needed. Ask the seller if he have some replacement bulbs.

Some solar lights offer some useful lighting modes to conserve battery power in the late evening, or a flashing mode for emergencies. However, avoir the superfluous, the low-end electronics improperly secured to the housing, or sensitive buttons often revealing on the quality of internal circuits.

Tight construction, at least the rain, is a nice option for these lamps for the great outdoors, especially in an environment close to the sea. In general, the solar lamps are now almost all "made in China" and the models found in the South, Madagascar and elsewhere, are often poor quality.
You will quickly have to tinker it. In this case, choose the simplest possible without electronic components, with a standard voltage, and a solid and removable case. Thereafter, the African ingenuity will do the rest...

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