Another solar question

I've read through a lot of the threads here regarding solar power and I'm interested in finally investing enough into getting a decent setup. I had a couple of questions first though.

Currently I carry a Trent IMP 880 battery pack for emergency use for my iphone. It's about the size of a pack of cigarettes, it has an 8,800 mah capacity and USB output. It charges from a wall socket, 12 v / 1A DC input.

With this I can charge my phone fully around 6 times, so I'm usually good for 3 days or so of normal use if I ever find myself without access to another way to power the phone.

Is there a product out there I can use to charge a battery pack like this? The end connector for the wall plug looks like one of the ones that generally come in those universal transformers. But I don't know what I'm looking for when it comes to specs on the solar panels... since this battery pack generally plugs straight into the wall (with only a transformer), I'm assuming it's protected with a built in charge regulator? So in that case, would I need one for the solar panel, or would it be a good idea in either case, to help regulate output in varying sunlight? I'm not sure what I would need wattage wise or what I should be looking for specs wise to charge a battery with this capacity in a reasonable time frame, though I doubt I'd be able to do it in a single day.

If the Solar PV panel doesn't have to be portable then something like this might be useful;

30W Monocrystaline Panel + 5A Solar MPPT charge regulator

The Duracell DPP-600HD Powerpack 600 Jump Starter & Emergency Power Source with Radio might be also worthwhile allowing you to charge the Trent IMP 880 battery pack during overcast days.

http://www.amazon.com/Duracell-DPP-600HD..._bxgy_ol_text_b

A DC-DC voltage regulator would also be useful if you wanted to step down the voltage from 12V to 9V, 6V, 5V, 4.5V etc.

I use a similar setup for a solar powered hi-fi system. (can also be used for also powering various battery chargers i.e. such as Ansmann Powerline 5 charger or Wireless router if required.

http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=175102

Thanks for the response,

For something like this I'd prefer a backpackable solar setup, though I really like the idea of having kind of a base station setup for a vehicle, maybe based around that Duracell Powerpack 600.

Regards,
Rob

Battery technologies like NiCD, NiMH and good old lead-acid respond rather well to trickle charging from a small solar panel. Rechargeable Li-ion batteries seem to need more current to charge effectively (but keep in mind I haven't played with the polymer type). Offhand, I'd say you're probably looking for a panel in the 10-15 watt range, which is pretty big for backpacking. I suggest you check with the manufacturer for minimum charging current, safe range for input voltage, and recommended options.

For a car-based recharging system, there's no need to buy a separate power source since you already have the vehicle battery.
- You can get a 75W modified sine wave inverter for about $10. Plug it into your cigarette lighter and use the transformer your battery pack came with.
- Or, you can get a regulated DC power supply which will hold the voltage at 12 VDC fairly exactly. I'm not sure if any of mine will supply 1 A though (I'll check in a few minutes and post the results).

If you have a voltage meter, check what the raw output (no load) of the wall charger is. That will give you some idea of how finnicky the battery pack is regarding input voltage.

EDIT: The Xantrex (no affiliation) VDC regulated power supplies I have would probably supply enough current. I picked up a couple of these for $5 each from a clearance store, including multiple tip styles.

Man i am so lost in all this converter, inverter, power output stuff. It's important stuff though so I try to read and comprehend as much as I can.

comms, it is a another language, but dont give up.

At the end, it all comes down to watts.

Volts times Amps equals Watts V x A = W.

wall power is 120volt. (AC power, it vibrates back and forth)
car batteries are 12 volt (DC- from battery to device)
AA, AAA batteries are 1.5 volts each.

Inverters take DC and convert to AC
Converters/regulators change voltage up or down within type- 12 volt to 5 volt, etc.

If you take 12 volt power and put it through an inverter, it comes out 120 volt. Since V x A = W, when you do this, you would put in 10 Amps of power at 12 Volt (10x12=120 watts) and OUTPUT 1 Amp of Power at 120 volts (1x120=120 watts)

http://www.suntactics.com/USBSolarChargerMoreDetails.html

Well it looks good. $140 or so. Guaranteed to charge iPhone, iPod, iPad, e-reader, Blackberry and almost every other USB cabled device.

I'll keep it in my comparison folder and read more reviews over the next couple months. Thanks for the link.

Also, the XL, here:

http://www.cpfmarketplace.com/mp/showthr...-2-panels-added

I saw a new company called Goal Zero at an outdoor show in Salt Lake City back in March. I was very impressed with their people and their product. What I liked the most was the scalability of their product. Batteries were designed to be daisy-chained for better amperage and solar panels were available from small to larger pedestal mounted versions designed for a base camp. They are definitely worth taking a look at.

been fooling around with a Goal Zero 7watt panel (about $80 retail)...it has a 12v as well as a USB port (was disappointed that it did not come with any other adapters)...it is in a tri fold cordura stiffened package...basic unit did not have a microprocessor controlled charger, but got one with 12v plug for about $20...charged 4 AA Sanyo Eneloop cells from out of package 1 bar to 3 bars (didn't have a meter) in about 4 hours (was charged when I returned)

Note the following two posts. He suggests it is preferable to get a 5V panel to drive USB charging (5V).

http://www.cpfmarketplace.com/mp/showthr...l=1#post2655099

http://www.cpfmarketplace.com/mp/showthr...l=1#post2651887

-john