Product Reviews

Eton Mobius Solar Panel iPhone 4 Case Review and Giveaway

Jackson Chung 29-05-2012

Eton Mobius Solar Panel iPhone 4 Case Review and Giveaway eton mobius reviewEver since I dabbled with iOS 5 beta, I’ve been an enthusiastic user of iPhone battery cases. Many would imply that using a battery case adds unnecessary weight and bulk to the sleek and sexy iPhone but personally, I think function trumps form. When I stumbled upon the Eton Mobius Solar Panel and Battery Case for the iPhone 4, three words crossed my mind: perpetual renewable energy. Wow, never having to charge my iPhone by plugging it in to a wall socket certainly is an enticing notion.


In this review, I’ll quickly run through the Eton Mobius, its strengths and weaknesses, so that you can decide whether it is something you’ll want to use. Plus, we’re giving away this $80 review unit to a reader. But first, let’s take a look at the Mobius.


The Eton Mobius Solar Panel and Battery Case for iPhone 4 and 4S is sold for $80 from Amazon. And if you haven’t guessed it yet, I was interested in the case purely for its solar panel charging system. How awesome would it be to charge my iPhone by harnessing the power of the sun? Unfortunately, it wasn’t quite that easy.

eton mobius review

I find it simpler to describe the Eton Mobius by breaking the entire case down to 2 sections. First, the iPhone compartment — it’s a partial snap-on case made out of hard plastic with a glossy finish. More specifically, it’s a partial snap-on because the part which holds the dock connector slides down and allows the iPhone to snap into place. This design is actually quite clever because there are no removable parts to deal with. Unfortunately, it also means that removing the iPhone from the case is a nearly impossible task because the plastic is so hard that it doesn’t give and there’s barely enough room to wiggle it out. I also discovered that the glossy plastic is quite easily scratched just by being placed on hard surfaces.

eton mobius review


As for the rest of the case, it’s pretty standard issue. There are cutouts in the case for the iPhone’s sleep/wake button, volume rockers and silent switch. The cutout for the headphone jack and noise cancellation mic is the largest that I’ve seen in a case like this.

eton mobius review

Eton also left a pretty sizeable chunk out for the iPhone camera, which helps the camera to take in as much light as possible and to prevent the flash from bouncing around.

eton mobius review


The second component is the solar panel which is on the other side and doubles the thickness of the case to 0.875″ or 2.22 centimetres. Compared to other iPhone battery cases, the Eton Mobius is really bulky. The “high efficiency” monocrystal solar panels are enclosed by cheap transparent plastic, surrounded by a border of rubberised plastic.

eton mobius iphone review

On the lower aspect of the case, things start to get confusing and honestly, a little crowded. There are 2 cutouts for the iPhone’s speakers, a solar charging indicator, a standby switch, a batter indicator button, 4 battery LED indicator lights, and a micro-USB port.

eton mobius iphone review


eton mobius iphone case review

Solar Charging with the Eton Mobius

If you think that you’d be able to just pop your iPhone into the case and start charging right away with the power of the sun, you’re dead wrong. And naturally, that’s what I did. I took a brand new Eton Mobius, inserted my iPhone and placed it under direct sunlight for a couple of minutes. And you know what? It just doesn’t work that way. In fact, the case drained my iPhone’s battery.

Here’s how the Eton Mobius works (or at least, is supposed to work): first, the 1800mAh battery pack needs to be charged either by using a micro-USB cable connected to a computer or wall socket; or by using the solar panel. Only then can it release the charge to the iPhone. So essentially, I was trying to charge my iPhone with a flat battery pack, and the solar panel was slowly recharging the battery pack, which released whatever tiny amount of charge it had to my iPhone. This initiated my iPhone’s charging process. In a matter of seconds, the battery pack had no more charge left it in, and stopped the charging process. While that was happening, the solar panel recharged the battery pack and the entire process is repeated. Did I mention I had my iPhone in silent mode? So whenever the charging process started or stopped, my iPhone would vibrate and consume more charge.


Right, lesson learnt — completely charge up the Eton Mobius battery pack before use. Like I mentioned before, there are 2 ways of charging up the battery pack — and of course, I opted to charge with sunlight! However, it takes roughly 8-10 hours of direct sunlight for a full charge, depending on the intensity of sunlight. Luckily, any form of bright light works just as well. You could just leave the Eton Mobius under a desk lamp or on a window sill and the solar panels will recharge the battery pack without any intervention on your part. If you’re unsure whether the solar panels are receiving enough light to initiate a charge, slide the standby switch over to the On position and if solar charging indicator lights up, you’re good. Solar charging will commence (and charge the battery pack) with the standby switch in either position.

eton mobius iphone case review

Still, waiting 10 hours to obtain a full charge is a long process. If you were to charge the battery pack with sunlight, Eton recommends removing your iPhone from the case. Charging the Eton Mobius under the sun even for a couple of hours with your iPhone intact isn’t a wise idea.

Charging up the iPhone

The 1800mAh battery pack claims to provide an additional:

eton mobius iphone case review

  • 6 hours of talk time or;
  • 8 hours of Internet use via 3G or;
  • 8 hours of video playback or;
  • 32 hours of audio playback.

An hour under the sun will allow the panels to charge up the battery pack with sufficient juice for:

eton mobius iphone case review

  • 25 minutes of talk time or;
  • 20 minutes of Internet use via 3G or;
  • 35 minutes of video playback or;
  • 145 minutes of audio playback

Since the iPhone only has a 1420mAh Li-Polymer battery, you would expect the Eton Mobius to more than double the iPhone’s battery life. That would be ideal but in real-world scenarios, it hardly happens. From testing, I managed to get approximately 60-70% extra battery life from charging with the Mobius.

Syncing with iTunes

Most modern iPhone cases allow synchronisation to occur through the case via the micro-USB cable provided without having to remove the iPhone from the case. By doing so, the case will also be charged simultaneously. Alternatively, you could just sync over WiFi.

With the Eton Mobius though, I’ve found that iTunes synchronisation only works with the standby slider in the Off position. To be brutally honest, synchronisation through the Mobius was iffy. The process isn’t documented at all in their user manual. However, it does work from time to time.

Should you buy it?

The solar panel battery case concept is truly exciting. I would have loved to charge my iPhone with just sunlight — just think about the immense geek cred I could have gained. Plus, I’m all about renewable energy so I’m completely behind the idea. Unfortunately, the Eton Mobius case fails to deliver in terms of both form and function.

Having to remove my iPhone and place the case out under the sun to charge for 10 hours makes me look like a bit of a cheapskate. The point to assert here is convenience; and I fail to see how the Eton Mobius makes my life easier. I would have been able to overlook that if the case was really slick but it isn’t. The Mobius thicker than most battery cases and the glossy plastic casing will be riddled with scratches over time.

So my verdict is, sadly, a negative one. I’ll admit that it could come in handy during a hiking trip or road trip. However, with better battery cases like the PhoneSuite Elite ($79.95) and mophie juice pack air ($79.95), coupled with the Mobius’ poor execution of solar charging; I cannot recommend the Eton Mobius for everyday use.

However, we’re open to the fact that you might think differently. So we’re giving this case away to one MakeUseOf reader to determine if the Eton Mobius is any good at keeping your iPhone charged in regular, day-to-day life. If you’d like to be in the running, join the giveaway below.

How do I win the Eton Mobius?

It’s simple, just follow the instructions.

Step 1: Fill in the giveaway form

Please fill in the form with your real name and email address so that we can get in touch if you are chosen as a winner. Click here if you can’t view the form.

The giveaway code required to activate the form is available from our Facebook page.

Eton Mobius Solar Panel iPhone 4 Case Review and Giveaway giveawaycodes

The giveaway is over. Congratulations, Lydia Chan! You would have received an email from Please get in touch with him before June 6 to claim your prize. Enquires beyond this date will not be entertained.

Step 2: Share!

You’re almost done. Now, all that’s left to do is to share the post!

Like it

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This giveaway begins now and ends Friday, June 1st. The winner will be selected at random and informed via email.

What do you think of the Eton Mobius? Have you experienced any other form of solar charging?

Interested in sponsoring a giveaway? We’d love to hear from you. Get in touch with us via the form at the bottom of this page.

Related topics: Battery Life, iPhone 4, iPhone Case, MakeUseOf Giveaway, Solar Energy.

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  1. Mark Thornley
    August 4, 2012 at 4:43 pm

    Makes the phone kind of bulky and it's a bit pricey though.

  2. Mark Thornley
    August 4, 2012 at 4:42 pm

    What a great idea!

    June 19, 2012 at 2:02 pm

    To what extent does the sun have to be prominent in the sky for this to work? It's all very well coming from California but if you live in a place, not quite as blessed with sunshine, how affected is the functionality of the device?

    • Jackson Chung
      June 19, 2012 at 2:04 pm

      It didn't work when it was cloudy. It needs direct sunlight to charge up the battery.

  4. Prakash Senapati
    June 2, 2012 at 6:09 pm

    why so bulky>>..........

    • Tina
      June 5, 2012 at 2:26 pm

      Guess the technology has to fit in somewhere. :)

  5. Brett
    June 1, 2012 at 4:57 pm

    these products are not made to give your battery a full charge. That is why america is lazy, because people expect everything to be done without lifting a finger! A product like this is made for emergency use or for "just in-case" measures. I keep seeing reviews sayings it takes 10 hours in the sunlight to FULLY charge your phone. You aren't suppose to leave your phone in direct sunlight for that long. Unless what you are trying to do, is give yourself a reason to need a new phone. The mobius is a product designed for someone stranded with no means of plugging in their phone. Who cares if you get 5% extra battery. That's enough to turn your phone on and make a phone call! which, at the end of the day, if you're stuck in the middle of nowhere, that's all you need.

    • Hilda
      June 1, 2012 at 5:14 pm


      I agree with you. We are looking at these to get them for hurricane season here in Florida in case we are without power for a few days and need to communicate with someone. Perhaps giving it an initial good charge prior to a storm or road trip.
      The article fails to mention how long the unit will hold a charge while not in use or on phone.
      Anyone know?

  6. Samsudeen Hussain
    May 31, 2012 at 8:54 pm

    My friend owns and iphone 4. I would love to gift it to him if i get this.

  7. igbo14
    May 31, 2012 at 11:37 am

    I want win the Eton Mobius

  8. Kyem Ghosh
    May 29, 2012 at 5:58 pm

    is there something available like this for nokia??

    • Jackson Chung
      May 30, 2012 at 4:07 am

      Not that I know of