10W solar panel cahrging phone directly.

[Guest]

Briefly, a 10W solar panel has been passed to me for evaluation purposes. It has a max. voltage output of 18V. I have wired it directly to a car ciggy lighter/USB adapator (this is rated input at 12/24V). In the moderate sun today it has charged the camera a treat, but never showing more than 7.5V at the adapter input. It simply cut out as the light level lowered (as one might expect.)

The experiment was a success, but is it safe/sensible to use it in this manner?

Will be very useful on the boat for Iphone etc.

Many thanks.

 

[Loafer]

It is safe, if it is passed to a smartphone by an appropriate charger. Your 12V-to-USB stuff SHOULD be fine. The Smartphone batteries are Lithium based, and ALL of those type of batteries require their own specialised charging regimes.

 

If you mess too much, they can expand, burst their packaging and set themselves alight. No ignition source required once the contents are exposed to air.

 

ETA overcharging is the biggest problem with these batteries, as is keeping them fully charged the whole time.

Edited January 23, 2016 by Loafer

[Phil Ambrose]

I have a double USB socket and 12v ciggy socket combined which I use to charge phones tablets etc but mine os wired to the boats 12v system. However my understanding is that the output of the USB charger is 5v regulated and IIRC they will take 12v or 24v. I bought mine from Vehicle Wiring Products and asked the questions prior to purchase

It works fine so I have no reason to think it would not work from your solar panel.

Phil

[tillergirl]

I have a double USB socket and 12v ciggy socket combined which I use to charge phones tablets etc but mine os wired to the boats 12v system. However my understanding is that the output of the USB charger is 5v regulated and IIRC they will take 12v or 24v. I bought mine from Vehicle Wiring Products and asked the questions prior to purchase

It works fine so I have no reason to think it would not work from your solar panel.

Phil

We have the same and charge our phones and tablets via a mini usb charger with no problems

[Guest]

I have used the cig lighter/adapter on the boat too, directly from the 12V and it works great (Asda IIRC.) It was one of those "I wonder what would happen if?" moments so I connected it to the solar panel. Connected with cheap plastic clothes pegs as an experiment; I will of course use quality wooden ones for the final fit

[ditchcrawler]

I have used the cig lighter/adapter on the boat too, directly from the 12V and it works great (Asda IIRC.) It was one of those "I wonder what would happen if?" moments so I connected it to the solar panel. Connected with cheap plastic clothes pegs as an experiment; I will of course use quality wooden ones for the final fit

Plastic are better as the wood could absorb moisture and then the then the resistance would fall.

[Guest]

Plastic are better as the wood could absorb moisture and then the then the resistance would fall.

Very true! I will fit a proper connector when I use it on the boat; a female ciggy lighter socket.

The next test is how many gadgets can it charge at the same time? Suppose it depends how sunny it is.

[Taslim]

Plastic are better as the wood could absorb moisture and then the then the resistance would fall.

Wood pegs should be OK once they have some roses painted on them and given a coat of varnish. I'd go fo PVC tape 'caue I'm not into tradition.

[Arthur Brown]

Trucks with 24v systems can use similar plug in USB chargers, these obviously take 24v so would offer an alternative method of getting 5v out of a solar panel at full power. In the average car or phone shop you have to look carefully for a cig lighter to USB adaptor that accepts 12 -24v but they do exist.

[Guest]

Thanks folks. Points noted about clothes pegs, so have gone mad and ordered a socket for a quid off ebay. On its way from Hong Kong as I type

Even though it is dull today, it is charging happily. Should keep all my USB rechargeable stuff ticking over nicely.

Next one is a USB charger that will work from the heat from the stove

Keeps me out of trouble.

[Phil Ambrose]

Trucks with 24v systems can use similar plug in USB chargers, these obviously take 24v so would offer an alternative method of getting 5v out of a solar panel at full power. In the average car or phone shop you have to look carefully for a cig lighter to USB adaptor that accepts 12 -24v but they do exist.

The input voltage was one of my concerns when I emailed Vehicle Wiring Products, they kindly emailed a PDF file of the spec complete with blueprint type drawing.

Phil

[Guest]

Yes my Iphone car to USB charger is 12/24V and pleased to say it works from the panel. Iphones can be a bit hit and miss from USB chargers in my experience.

Kindle needs a sunnier day though.

Edited January 24, 2016 by Guest

[Arthur Brown]

My newest (I have several!) DC to laptop adapter accepts 12 -24v nominal and gives a good supply to my 19.5v Dell which has previously proved challenging to power from 12v. BUT it's ca 70w so little value with a 10w panel.

[MarkHez]

Surely its much more effective/efficient to have the panel charging a small 12v battery, and then charging your devices from that?

[Guest]

Surely its much more effective/efficient to have the panel charging a small 12v battery, and then charging your devices from that?

I have thought along those lines too. Maybe a rechargeable alarm panel battery or similar?

[WotEver]

Like a little Yuasa. Dead cheap online.

[Guest]

cheers will look towards that idea.