I’m a big fan of solar chargers. If you can charge devices with no more than the power of the sun, what’s not to like? Well, quite a lot, actually, For example how about absence of sun, the fact that chargers can take a while to charge, difficulty with access to all the connectors you need and relatively low charge capacity.

I’ve had a few Freeloader solar chargers in my time, and never really found one that I’d be prepared to use long term. I think I’ve turned that corner with the Freeloader iSIS. It isn’t without its annoyances, but the iSIS is the best portable solar charger I’ve yet tried.

Freeloader iSIS shell front

Very importantly the Freeloader iSIS small and quite light. Its 240g of weight and 25mm x 76mm x 137mm take into account a gel shell which you’ll probably use a lot of the time. The shell provides shock protection and a degree of water resistance. On its back there’s a loop which is great for securing the charger to a rucksack while you are out and about, and, thanks to a provided Velcro strap, to various items around you when you stop – the top of a tent, somewhere on your boat, well, you get the idea.

Freeloader iSIS shell back

You have to take the Freeloader iSIS out of its shell to get to a small kickstand that’s really useful for angling the charge panels at the sky. Most likely that’s what you’ll do when you stop for lunch on your trek, or stop for the day, as the Freeloader iSIS captures most power when it is pointing at the sun.

Freeloader iSIS stand

The Freeloader iSIS also needs to be free of its shell for you to get at its charge cables. There are two longer cables – a lightening connector for your iPad or iPhone and a micro USB for all manner of devices including Android and Windows Phone smartphones.

Freeloader iSIS charge cables

There’s also USB output so you can attach another charge cable and a micro USB for charging the Freeloader iSIS itself from the mains. Doing that is a very good idea – it means you can start a trip with a full battery, and top via solar as you deplete the internal storage.

The 4000mAh battery that’s inside the iSIS is rated as good for up to three full smartphone charges, or one charge for a tablet, or up to three chargers for a camera or games console. You’ll get used to how it works with your equipment, but I found it charged my iPad and Google Nexus 5 with no bother at all. It can even charge two devices at once.

A small LCD panel shows you how much battery charge is remaining if you press a side button, tiny indicators remind you of whether it is charging by the sun, via USB or even via a ‘separate charge panel if you have one.

In general use I found the Freeloader iSIS to be a good standby device, and I’d be happy to use it longer term. There are some important points to note, though. It is not fast to charge – it needs between five and ten hours of sunlight to fully charge. It charges much more slowly if it is not facing directly at the sun, and if the day is cloudy. If you try to charge it from behind glass – for example on your car dashboard, be prepared for a long wait because of the UV filters in much glass.

The Freeloader iSIS can struggle to provide top-up charging. It works best when the device it is charging has less battery power than it does. It can’t charge anything that requires more than 5.5v. And camera batteries can only be charged if you buy an extra piece of kit – a charge caddy.

Oh, and of course, you’ve got to be prepared for a pretty steep upfront cost of £65.

  • Light and portable
  • Built in charge cables
  • Can charge two devices at once
  • High capacity
  • Good quality gel case


  • Relatively slow to charge
  • Can struggle to top up batteries
  • Camera batteries need an add-on caddy

Manufacturer: Freeloader

Price: £64.99