Stupid Question of the day.... Solar powered shed light ?

Biddy · Post by **Biddy** » Sun Mar 11, 2007 11:25 pm

You might think me a complete numpty but I'll ask anywhoo. £14.99 local hardware shop. Full charge 2x AA batts powers 1 watt super bright flourescent lasts 1.5 hrs. panel 16.5cmx11.5 1.55m cable. Do you think it pos to use panel to charge anything bigger like a 6v motorcycle battery.
Thinking may be able to adapt for internal lighting. or portable dvd's and games. I dont' mind being called silly.

http://tinyurl.com/28ot8h this is same one only costs more.....

Peg leg Pete · Post by **Peg leg Pete** » Sun Mar 11, 2007 11:29 pm

I think it will power the lamp fine, but the 6 volt battery will require a higher wattage solar panel

Post by **francophile1947** » Sun Mar 11, 2007 11:32 pm

Hi Biddy
You're a complete numpty!!

As it charges 2 x AA batteries, it's output must be in the order of 3 volts - have you got anything that needs so little power? Also, I suspect it would take a very long time to charge the batteries.

moonshine · Post by **moonshine** » Sun Mar 11, 2007 11:34 pm

In theory it may be possible, but I wouldn't think it practical due to the length of time it would take to charge. However, solar panels which will charge quite large batteries are available, but at a price. Many of my boating friends use them to top up their leisure batteries ready for when they return to their boats the following weekend.

Biddy · Post by **Biddy** » Sun Mar 11, 2007 11:42 pm

francophile1947 wrote:Hi Biddy
You're a complete numpty!!
As it charges 2 x AA batteries, it's output must be in the order of 3 volts - have you got anything that needs so little power? Also, I suspect it would take a very long time to charge the batteries.

No harm in asking if you don't know... THANKS PEEPS looks good enough for children's DS

Post by **francophile1947** » Mon Mar 12, 2007 12:10 am

No harm at all Biddy - that's what the forum's about.

mikeonb4c · Post by **mikeonb4c** » Mon Mar 12, 2007 12:13 am

Dandys the guy to answer this one. He's got a whopping big one and its stuck to his roof

moonshine · Post by **moonshine** » Mon Mar 12, 2007 8:09 am

Brings tears to my eyes......

skyhigh123 · Post by **skyhigh123** » Mon Mar 12, 2007 11:58 am

You could try this from Maplins- reduced from £19.99 to £9.99. I bought one and certainly the LED flashes merrily during the day while it's attached to my motorbike battery. I've yet to be convinced that it actually works in terms of delivering a useful charge- (why are they selling them off cheap?)

http://tinyurl.com/yuwezp

trevd01 · Post by **trevd01** » Mon Mar 12, 2007 9:23 pm

Here's a little test:

Q:
The cheap maplins solar chargers are 1.5 watts = 0.125 amps.
If a leisure battery is 110 amp/hrs how long will it take to charge it from flat?

A:
Probably infinity, i.e. it will never charge it. Although theoretically, given 8 hours continuous sunshine every day, maybe 110 days.

I'm sure someone will correct me if my electro-maths is wrong!

{EDITED} And Franco did

Edited to show correct figure!

Post by **francophile1947** » Mon Mar 12, 2007 9:35 pm

Close Trevor - it would take 110 days at 1amp (8 x 0.125) per day

Absolutely useless for anything other than keeping an unused battery topped up.

mp3oplecarrier · Post by **mp3oplecarrier** » Fri Mar 16, 2007 10:20 pm

They are CLEARLY for supplying a top-up charge, particularly useful for vehicles like ours with lots of electrical goodies or vehicles that are not run often.

dandywarhol · Post by **dandywarhol** » Sat Mar 17, 2007 12:05 am

Even my whopping big 'un on the roof only gives about an amp - as folks say, just enough to trickle charge it during the 20 hours of sunshine we'll have up here when the clock's change...........