Hi:Just bought a Thunderbolt 1.5 watt solar charger for my RV from Harbor Freight. The box and ads suggest that you can simply plug into cigarette lighter. The instructions, however, say that you should not use it without a voltage regulator. The output, open circuit, easily reaches 22 volts. Do I need the voltage regulator and, if yes, any suggestions for what to buy?

1.5 watts is a joke. What are you using this for?

The output is so minimal you can leave it connected 24/7/365 without concern of anything other than your battery going dead. It can only keep a fully charged battery up if there are no loads on it.You really should go get your money back.

It would be used to keep the truck battery charged between uses.

Does the truck have a alarm? This set up will not provide for enough to offset what that alarm will pull.It is cute though. :)

Ok, but you have to realize that its maximum output is around 0.08a, and that's only for a few hours on a really sunny day.

Thunderbolt 1.5 watt solar charger | Good Sam Community

2oldman
Explorer II
Oct 13, 2015
TomG2 wrote:
Hey Saint Augustine, how does it feel to have your question answered with sarcasm, derision, and condescension?
I see mostly honesty, but let's wait and find out.
gkainz
Explorer
Oct 13, 2015
I think our OP slipped his decimal one place. The Thunderbolt panel I see on Harbor Fright's website says 15W...
http://www.harborfreight.com/15-watt-12-volt-solar-panel-96418.html

Edit: oops, perhaps not ... there is a 1.5W Thunderbolt panel - even tho the link says 15W
http://www.harborfreight.com/15-Watt-Solar-Battery-Charger-68692.html
TomG2
Explorer
Oct 13, 2015
The OP asked a simple question, "Do I need the voltage regulator and, if yes, any suggestions for what to buy?", and nobody answered him. I can understand his confusion and would try to help if I was a solar expert.
Saint_Augustine
Explorer
Oct 13, 2015
TomG2 wrote:
Hey Saint Augustine, how does it feel to have your question answered with sarcasm, derision, and condescension?

It helps keep us all happy!
TomG2
Explorer
Oct 13, 2015
Saint Augustine wrote:
TomG2 wrote:
Hey Saint Augustine, how does it feel to have your question answered with sarcasm, derision, and condescension?

It helps keep us all happy!

Hey, if you are happy, I am happy. I thought you wanted an answer to a specific question. Take that worthless POS back where you got it.
Saint_Augustine
Explorer
Oct 13, 2015
It is a trickle charger or float charger. It simply maintains the voltage. I have used a plu in "float" charger on my tractor battery for several winters with success. Starts immediately. Neither of these devices are meant to "charge" the battery.. Some of you might try "bib gig" the concept. I was hoping for an informed response. Thanks anyway.
red31
Explorer
Oct 13, 2015
No controller needed IMO.

http://www.solar-electric.com/solar-charge-controller-basics.html

"A rough rule is that if the panel puts out about 2 watts or less for each 50 battery amp-hours, then you don't need one."
Saint_Augustine
Explorer
Oct 13, 2015
Saint Augustine wrote:
It is a trickle charger or float charger. It simply maintains the voltage. I have used a plu in "float" charger on my tractor battery for several winters with success. Starts immediately. Neither of these devices are meant to "charge" the battery.. Some of you might try "bib gig" the concept. I was hoping for an informed response. Thanks anyway.

The plug-n charger produces 400ma max and works. The "bib gig" was meant to be "binging" instead of "googling" as I tend to use "Bing" for my internet searches.
Saint_Augustine
Explorer
Oct 13, 2015
red31 wrote:
No controller needed IMO.

http://www.solar-electric.com/solar-charge-controller-basics.html

"A rough rule is that if the panel puts out about 2 watts or less for each 50 battery amp-hours, then you don't need one."

Thanks for this.
time2roll
Nomad
Oct 13, 2015
Yes about 5 watts per battery does not need a controller.

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