Solar shed light

[Tinbendr]

So, I purchased one of those shed lights from Harbor Freight several months ago.

The light worked several times after installation, but then stopped.

I finally took it down this past weekend to see what the trouble was.  Well, heck the batteries are dead (4 AA)

Further investigation revealed the panel is only putting out 7 volts in open voltage.  That is not enough, correct?  

When I insert the batteries the voltage goes to zero.

It's had plenty of full sun for at least two weeks.  I've also had the light unplugged just to make sure the light wasn't in the on position.

TIA

[wdyasq]

4 1.2V nicads are below 7V... Possibly you only have bad bateries.

Ron

[dnix71]

I have 2 of these solar LED's shed lights. Used them over a year every day with no trouble. The panel output is weak, but that's apparently by design, otherwise it might overcharge. My panels only see direct sun for a few hours, but it works.

http://www.ikitchen.com/079-709410.html?CS_003=740477&CS_010=079-709410

Bought them at Home Depot and paid about $25. They put out less light, but I've accidentally left them one all day and 9 hours later they still worked (dimly).

I avoided getting the flourescent light version from HF because of it's power use.

4 watts is a moderate drain on AA bats, esp. NiCads. The rating on NiCads from HF is only about .8AH

I can't explain the price variation for this. SunForce makes it, but the price varies from $15 to $60. Home Depot discontinued carrying them so I paid less for the second one.

One of these lights my bathroom (6' x 12').

[wooferhound]

My guess is that the batteries that come with those lights are not the best quality in order to keep the price down. it also sounds like they are charging the batteries directly off of the solar panel without anykind of charge controller due to the 7 volt output from the panel.

[Tinbendr]

QUOTE:it also sounds like they are charging the batteries directly off of the solar panel without any kind of charge controller due to the 7 volt output from the panel.

Yes, the batteries are wired in parallel to the light.  I was thinking the light should work without the batteries.

The panel may not be powerful enough?

I'll look around for some different batteries and see if that'll work.

[Norm]

  It was designed to work long enough for you to

turn on the shed light at night long enough to

find the lock on the shed get the right key....

step inside the door get what you wanted in the

shed...lock the door and turn off the light and

let it recharge the next day ....if the sun shines.

  You should go 2 steps further on your check

recharge the 4 AA batteries to 4.8 total voltage

and see what the charging voltage is (probably

about 6.5) then check the current ....something

like 100 ma. will work

 

[Tinbendr]

I had a chance to look at this again.  (Been busy with graduation this week of my oldest son from High School.)

I had ordered a NiCd charger and batteries from HF.  When it came in, I charged the batteries from the solar light.

I inserted the batteries and the light came on.  It stayed on about 30 seconds, then when off.  WTF!  I could smell the magic smoke.  I touched the batteries and nearly burned my hand.  The springs in the battery holder were glowing red.  I opened the solar panel (the batteries are mounted behind the panel.) and found the panel was wired backwards to the batteries. (The + lead was attached to the + of the battery.)  Switched the wires and everything appears to be normal. (No magic smoke)  It appears to charge properly under incandescent light.

[valterra]

If the solar panel is supposed to charge the batteries or power the light, then the Red (+) from the solar panel SHOULD be on the Positive (+) of the battery!