Heating & energy

Solar & dynamo torches

Updated: 04 Nov 2009
09nov-solar-troch-hero

Introduction

We tried 9 solar- and dynamo-powered torches and torch-radio combos.

Some of them performed better than others. The niftiest ones are a useful standby when the power’s out or you’re off the grid.

Note: this report is a guide only and doesn't contain test results or brand-specific recommendations.

Power sources

A dynamo torch-radio

Several of our gadgets were powered by a hand-cranked dynamo, others were pure solar, and a third lot had both options.

All the solar-powered torches and radios we tried fired up quickly. We didn’t even have to put them in the sun: indoor light gave them enough juice to start.

Most of the dynamo-powered gadgets we tried also delivered results – though they take a bit more effort: you have to wind a handle to charge the dynamo battery. A small dynamo-powered torch can be cranked up pretty quickly. But bigger power users take a lot more cranking … and you don’t always get much for your effort.

Torch-radio combos

We tried three torch-radio combos. Two of them had both solar- and dynamo-charging options, so the dynamo could provide a back-up if the solar ran low.

The third (and most expensive) model was dynamo only (a Digitech brand from Jaycar Electronics). It took a few minutes of winding to get the radio going … only to have it peter out soon after. The instruction manual said you could charge the device by plugging it into the mains (although an adaptor wasn’t included). A full charge by this method took 12 hours!

By comparison, the two solar/dynamo models gave us solar-powered sound with no effort. We got reasonable reception (and torch light) from both. The Eton Microlink ($64.95) gave us superior sound compared with the other unbranded solar/dynamo model ($39.95). The sound quality of the Eton Microlink was similar to a battery-powered transistor.

Of the two, the Eton Microlink was the most compact. You could hold it easily in the palm of your hand and it would tuck away nicely in a picnic basket or backpack. It’s designed to provide up to three hours of radio play when fully charged.

The unbranded solar/dynamo model was bigger and could also use AA batteries.

Products compared

Digitech dynamo torch-radio

Digitech

  • Retailer: Jaycar Electronics
  • Price: $71.90
  • Description: dynamo radio and torch (3 LEDs)
  • Extra features: clock, emergency alarm, reading light, mobile-phone charger, mains input, AA battery option
  • Dimensions L x H x D (mm): 200 x 130 x 75 

 

Eton Microlink solar/dynamo torch-radio

Eton Microlink

  • Retailer: NZ Nature
  • Price: $64.95
  • Description: solar/dynamo radio and torch (3 LEDs)
  • Extra features: mobile-phone charger, USB port
  • Dimensions L x H x D (mm): 126 x 60 x 46 

 

Unbranded solar/dynamo torch-radio

Unbranded

  • Retailer: NZ Nature
  • Price: $39.95
  • Description: solar/dynamo radio and torch (1 standard bulb)
  • Extra features: mains input, AA battery option
  • Dimensions L x H x D (mm): 203 x 114 x 76

 

 
Guide to the product listings

Products were selected from retail stores and online. Other brands/models are available.

  • Price is what we paid in September 2009.
  • Description shows the details of the product taken from the packaging.
  • Dimensions show approximate size. 

Small torches

We tried 5 small torches: 2 were solar, 2 dynamo and 1 a solar/dynamo combo. All 5 used light emitting diodes (LEDs) as the light source and did an acceptable job when we took them for an hour-long evening walk.

The strongest light was provided by an unbranded solar torch with 10 LEDs from Jaycar Electronics. The other models each had 3 LEDs.

We also tried a torch that’s powered by shaking it: the shaking causes an internal magnet to pass through a coil of wire and create electricity, which powers the single LED. The torch worked: a few good shakes lit up the LED. However, you could get tired of having to shake it every time the light started to dim.

Products compared

Benex dynamo torch

Benex

  • Retailer: Dick Smith
  • Price: $19.99
  • Description: dynamo LED torch (3 LEDs)
  • Extra features: n/a
  • Dimensions L x H x D (mm): 135 x 40 x 60 

 

Unbranded solar/dynamo torch

Unbranded

  • Retailer: Jaycar Electronics
  • Price: $35.90
  • Description: solar/dynamo LED torch (3 LEDs)
  • Extra features: n/a
  • Dimensions L x H x D (mm): 150 x 30 x 50 

 

Unbranded solar torch

Unbranded

  • Retailer: Jaycar Electronics
  • Price: $17.90
  • Description: solar powered flashlight (10 LEDs)
  • Extra features: n/a
  • Dimensions L x H x D (mm): 210 x 45 x 45  

 

Supertiger dynamo torch

Supertiger

  • Retailer: Mitre 10 Mega
  • Price: $18.97
  • Description: dynamo flashlight (3 LEDs)
  • Extra features: mobile-phone charger
  • Dimensions L x H x D (mm): 135 x 45 x 55 

 

Unbranded solar torch

Unbranded

  • Retailer: NZ Nature
  • Price: $34.95
  • Description: solar tri-panel torch (3 LEDs)
  • Extra features: mobile-phone charger
  • Dimensions L x H x D (mm): 160 x 30 x 55 

 

Unbranded shaking flashlight

Unbranded

  • Retailer: Repco
  • Price: $4.75
  • Description: shaking flashlight (1 LED)
  • Extra features: n/a
  • Dimensions L x H x D (mm): 180 x 35 x 35 

 

Guide to the product listings

Products were selected from retail stores and online. Other brands/models are available.

  • Price is what we paid in September 2009.
  • Description shows the details of the product taken from the packaging.
  • Dimensions show approximate size. 

 

Mobile phone chargers

Using a mobile phone

A couple of the devices we looked at had attachments for charging mobile phones. But this was their least successful use. The attachments didn’t fit several mobiles we tried. You can buy extra attachments though these cost up to $10 each.

And it can take a lot of effort to get your phone charged. For example, the Eton Microlink stated it could take 10 to 15 minutes of winding the dynamo to get a mere one minute of talk-time! Not what you’d call a good return on your energy investment.

We didn’t have much luck with charging our mobiles by solar-power either. Several hours after plugging in one phone, we still had no joy. Charging can depend on the age and type of the phone battery and not all devices will fully charge your phone.

Instructions for the (unbranded) solar tri-panel torch said its mobile-charging mechanism “may charge halfway or more but it’s not designed to provide a full charge”.

If you really want to charge a mobile by solar power, we suggest you look for a dedicated charger.
 

Buying tips

 

Consider models with both solar and dynamo capacity. A mains input – so you can plug the device into a wall socket – can come in handy for extra-fast charging.

And before you buy …

  • Find out the charging time and power duration (especially if you’re buying a mobile-phone charger). Some of the gadgets we looked at didn’t give any information about how long they’d run for once they were fully charged.
  • Ask what the expected life is and whether you can get replacement parts (this may be unlikely for products at the cheaper end of the market). Batteries can need replacing over time – as can solar panels. But we think you should expect to get reasonable service out of them, just as you would with similar battery-powered products.

Our view

  • Solar- and dynamo-powered radios and torches can be useful as a back-up or if you spend time away from the main grid. They can also be handy when you’re travelling because you don’t have to worry about batteries.
  • Manufacturers could make these devices more user-friendly. An indicator to show how much juice they’ve got in them would be a start. None of the ones we tried had this.

 

Report by Jessica Wilson.