Solar charger for SPV

[Guest hunchback]

Hi, coming up to the 1st anniversary of my ownership of a SPV (Canary) smartphone, the phone has been well travelled, up mountains, on various train journeys across Europe and the odd "short" flight to the USA.

Calling all geeks! Just in case you don't know...

Background: the SPV (Canary) supplied battery is 3.7V 1000mah. This is charged via a 5V mains charger or (via cable) USB sync+charge.

My Orange SPV (Canary) does charge successfully in either sunlight or strong daylight from a portable solar panel. The one I use is the "Isun" model you can get in Maplin or various online sellers.

Manufacturer's website: http://www.icpglobal.com/html/isun.asp

The Isun outputs 6v/12v via a switch setting, the 6v setting works fine in my experience with the SPV using the supplied Isun cables, which you plug into the base of the SPV-supplied portable charger adaptor (i.e. that plug that you get with the SPV that plugs into the SPV mains-charger and then into the base of the SPV). Warning! The isun is meant to output anything up to 7.6V in the "6V" setting whilst the SPV is meant to be charged with a 5V charge - so in theory you can fry the SPV battery. Just from a personal experience the isun doesn't fry the battery (perhaps I've been lucky!) but you do this at your own risk!

The isun makes about 290ma at the 6v setting, which means a full battery charge (from SPV flat battery) takes about 4 hours. This may sound long, but essentially in sunny conditions means a full battery charge per day. Given "normal" SPV usage (I class as my usage!) my SPV battery lasts about 2 days, so means I can essentially survive purely off Solar power during sunny conditions. The winter-sun we're getting now is fine, just need to ensure the solar panel is tilted towards the sun.

The isun comes supplied with "suckers" which with some spit and a clean surface sticks to a window (I do this on the train) and helps direct towards late-afternoon sunshine.

How to survive non-sunny conditions? Well (this adds weight+cost), I also have the Battpak add-on to the isun:

http://www.icpglobal.com/html/battpak.asp

This allows to charge the SPV off rechargeable batteries (requires 4 or 5 batteries to get to 5V required by the SPV). These 5 batteries can be charged by either mains, the isun Solar panel, or regular 12V car-cigarette-lighter. Using regular AA NiMH batteries I find 5 batteries required, as each battery gives about 1.2V and 4 batteries isn't enough. But if you used Alkaline batteries (e.g. Duracell) then they give higher voltage so 4 batteries might be sufficient. I encourage use of NiMh rechargeables purely from a cost and saving-the-planet perspective.

My modus-operandi is to not plug the isun direct into the SPV as this forces the SPV to be connected to the solar panel, and in the sunny weather I'm just moving about!, so I use the isun+battpak to charge 5 NiMh AA batteries at "basecamp", and then in the evening/night after a days wandering round, connect the SPV to the battpak for charging. In this mode, essentially you can survive indefinately. The advantage of using battpak and AA NiMH is that each AA battery (modern battery = 2000mah) can do between 1 and 2 full battery SPV charges, so in a prolonged dull-weather using 5 AA NiMh batteries = 5 to 10 SPV battery charges, the AA batteries will run down whilst charging the SPV, and the AA batteries can get some charging from the isun over the period, so then so long as there is some sunny weather eventually you'll survive.

So, if you are thinking of wandering for extended periods, somewhere without access to mains-or-cigarette-sockets, you can enjoy the benefits of the SPV for a few weeks (longer if you can get good sunny conditions).

If you wanted to survive in complete darkness, then a bunch of AA batteries and the battpack will suffice. A bunch of say 10 AA batteries should in theory do 20 SPV battery charges. If this is of interest you then you can save £ and cut out the solar panel altogether and just use the battpak.

Aside: the above applies to many other devices, I also keep a Psion Revo charged and batteres for my maglight.