Recommended Solar Gizmo Charger?

System

Hi, I have a new HTC tilt, older iriver ihp-120, and a canon sd700is, and LED flashlight (AA batteries) all of which I want to be able to keep charged. I have been scouring sites trying to find the ideal travel solar charger and am thoroughly confused at this point.

Ideally I would be able to find something that is under $120, fairly portable, has an internal battery (to charge devices when the sun isn’t out), and can recharge AA batteries. I have found many things that are portable and *either* have a AA battery charging option or an internal battery option but not both and almost none of the things I have found so far have uniform reviews (like the isolio seems to be one of the closer thing to what I need but some reviews are great and others are horrible).

Any help, suggestions, pointing me to comparisons, etc would really be appreciated!

Cheers

-Gaiko

System2

Re: Recommended Solar Gizmo Charger?

This is an intriguing deal:

"Powermonkey eXplorer-Solar Charger for Cell Phones, MP3 Players, iPods, PDAs, PSP and Digital Cameras..."

This thing normally sells for over $100, but Buy.com has is on a special sale for just $10 after rebate. Seems too good to be true. Free shipping too.

http://www.buy.com/retail/product.asp?sku=206229854&adid=17051&dcaid=17051

It comes with various adapters and cables... plus 2200mA of standby battery in the solar pack...

I might just need to pick one up to play with...

- Chris // www.technomadia.com

mike95490

Re: Recommended Solar Gizmo Charger?

That's going to be a bit tougher.
Something that has an internal battery, and can use that to recharge other batteries.

There are Solar AA & AAA chargers. Most need a full day of sunlight, because they have a tiny PV panel.
here's a kit, which has scant info about what exactly comes with it.
http://thomasdistributing.com/shop/icp-global-isun-solar-battery-chargerbrsolar-charger-combo-kitbrincludes-portable-solar-charger-and-battpak-aa-aaa-charger-p-1080.html?SP_id=&osCsid=7ve4rjgov74v5p4csr0rdmopk0

The host company of this site, has listed on their home page, some scratch and dent 50W panels.
http://store.solar-electric.com/su50wa12voso.html

Combined with a 12V deep cycle battery, you could use a simple charger
MAHA MH-C9000 to charge AAA or AA batteries
http://thomasdistributing.com/shop/chargers-by-model--maha-mhc9000-c-147_148_150.html?osCsid=7ve4rjgov74v5p4csr0rdmopk0

This may be more flexible, but it will cost more, you are getting a lot more solar panel.

A "toy" 5 watt panel may keep 1 cell phone going, or 1 pair of AA batteries, but for several gadgets, you need to get a larger solar panel to capture the sun with.

BB.

Re: Recommended Solar Gizmo Charger?

What are your expectations?

Most (all?) of the small/portable solar chargers have panels that outputs hardly any energy at all...

A typical unit: 150mA for charging 2 rechargeable batteries at a time.

The AA NiMH battery? 2,000 mAH.... 2,000mAH/150mAH=13+ hours of full sun (~3 bright summer days for 2 AA batteries).

If you want a unit with another internal rechargeable battery--the efficiency drops even more (with same size solar panel may take 2x longer). 150mAH*5 volts = 0.75 watts

So, you can look at a larger system with its own battery. This Xantrex unit has a 5 watt solar panel and a 10 amp*hour AGM battery. Even includes a 400 watt inverter.

Use the 12 volts or 120 VAC to power any charging station of your choice.

Down sides; weighs almost 20 lbs. To charge 4xAA NiMH batteries will probably still require over 1 day (5+ hours of sun) from the solar panel. Even though it has a 400 watt inverter inside, a reasonable use would be a few tens of watts for 10 hours maximum before recharging the battery. To recharge the internal battery only from the attached solar panel would take 20-40+ hours (4-8+ days of full sun). Better, but probably still not what you are looking for.

In the end, getting as large as solar panel as you can, and matching to the sort of cells you want to charge is probably your best bet. Pick a thin film flexible panel if you need something that is a bit harder to break when traveling (regular solar panel would be smaller--but think of carrying a sheet of glass as you travel).

You might look for something like this 5 watt panel for $72.

• Peak Power = 5 Watts
• Voc (Volts at open circuit) = 23.8 Volts
• Volts @ peak power (load) = 16.5 Volts
• Isc (Amps @ short circuit) = 0.37 Amps (370 milliamps)
• Amps @ peak power (load) = 0.30 Amps (30 milliamps)
• Power cable is attached
• Instructions are included
• 10 year warranty

I am not sure--but the dimensions may be about 19.5"x8"x0.9" (hard to find any data sheets for this).

5w/16.5v=0.3 amps... Assume it takes about 2-3000mAH to charge the average 100% depleted AA NiMH battery, that would be about 10 hours of sun to charge from 1 to 8-10 cells in series. Add a Schottky blocking diode in series (to prevent cell discharge at night), and you have a charger than can charge either 1 or a bunch of batteries in 2 days (ideally, all batteries in the string should be discharged, roughly, the same amount). Since the charging current is roughly 1/10, you don't really need any electronics (current it to low to damage batteries left on for a day or to extra).

You might try and find a regular 2 or 4 cell NiMH charger that can run off of an external solar panel...

If you are going to have a laptop computer anyway--you can get a USB charger that will recharge 2xAA batteries in 4 hours.

Here are some very portable 10 watt solar panels--not cheap. Claims to work with 12vdc (15v) chargers...

I did a quick look around, and it is difficult to find a 12vdc battery charger with low enough input current for use with small solar panels.

The other way to go... If this is not an endless trip. Look at AA Lithium cells (Energizer L91BP AA Lithium Batteries). In some applications (cold weather, high drain), the Lithiums can outlast Alkaline and NiMH by many times. Also, Lithium can store for 5-10 years and work at lower/higher temperatures (-40 degrees to 140 degrees F) vs NiMH.

Granted, they are about $2.50 to $3.00 each--About the same price as a good Sanyo Eneloop AA NiMH Hybrid battery. And if they last 2-5x longer than NiMH or Alkaline in your application (assuming digital camera)--that is the same as if you did 2-5+ recharge cycles with the NiMH batteries.

-Bill