I recently came into possession of one of these:



It only has a 12V plug on it.....

Should I use this? would it be beneficial?

If I were to use it through the 12v source, it is a key on only, wouldn't leaving the key on, pretty much negate any help this would give? and require me to be in the van?

 

Did it come with any packaging or anything describing what it's supposed to be used for? Looks like one of those battery maintainers. It feeds power through the lighter port to maintain the battery. That's my guess, without any other descriptions of it, who knows.

 

yep he's right.

 

It only works in a 12v outlet if the outlet still has power when the key is off. Leaving the key on would as you say, negate any benefit. When you buy them new it also comes with a pigtail with battery clips. That's the reason for the 2-prong plug in the cord...to swap between the clips or the lighter plug.

 

I didn't get this one new, and it is wired directly to the cigarette lighter plug, no connector....

So to use this, I would need to jsut leave it on the dash, and wire it directly to the battery? Would I need to wire in an on/off switch? Will it cause an over-voltage situation, or is it just fine to leave it connected 24/7?

 

No on off switch needed. Most come with circuitry that prevents discharge of the battery when there is no sun. As stated, it needs to be used on a power point that is constant on.

 

Also it is made to maintain the charge - not to quickly charge.
If you had a battery at 50%, it would take about 5 days to charge it back to 100 with that panel

BTW I have the same one for my trailer

 

Yeah I know it isn't for a quick charge, I have an actual charger for that, and even then, they aren't quite quick.

Sounds like I can just wire it up directly to the battery, and let it sit on the dash

 

There is a diode wired inside it. That diode allows the panel to send juice to the battery while preventing the battery from backfeeding into the solar panel. So technically you can leave it connected while the engine is running, but if the diode fails you'll likely smoke the solar panel.

 

It was free, so I am not too worried about it