[norm356]

actually, electricity doesn't care which way it "goes", so long as your battery tender's max power output does not exceed the fuse size on the otherwise unused wire while the car is sitting, the wire won't be able to tell the difference

However, after searching throughout the engine room and wire diagram yesterday for a good place to connect my battery tender, I, too, came to the same conclusion as fox: the battery is the most convenient place to do it.



In reply to the above posters who'd asked where they could attach their solar charger, inside of the cabin, I do want to add what fox pointed out to my reply above: make sure the max power output of your solar charger does NOT exceed the fuse size of the +12V wire you are going to connect it to.

 

[zzyzzx]

Do not hard wire a charging wire through a powered wire. You'll end up burning out the wire. Wire it straight to the battery. Think of electricity as a water flow. It goes in one direction, from the battery to the radio (For example of course). Adding more and going in the opposite direction will not work so well and will eventually blow out. You risk setting a car on fire by trying to force power back into the battery.

Wire it straight to the battery. Solar chargers are not designed to be permanently attached nor are they designed to be used while the vehicle is operating. They are essentially battery tenders. You can cause major damage to either the battery or to your solar charger if you leave it attached while operating.

I'd like you to justify these statements....
The 1.5 watt (which is tiny) solar charger isn't going to cause any of these issues..
The type of solar panel that could cause what you describe is probably going to be bigger than the car.

 

[foxtherouge]

I'd like you to justify these statements....
The 1.5 watt (which is tiny) solar charger isn't going to cause any of these issues..
The type of solar panel that could cause what you describe is probably going to be bigger than the car.

I can very easily justify those statements. We have solar chargers in the army. Some genius decided to wire it to the vehicle instead of using the NATO receptacle like you are supposed to. Humvee burned to the ground in the field out in Yakima during the summer where there is lots of sun. It overcharged the batteries which then spiked and burned the wiring they attached to. Huge investigation on it.

I think you are underestimating how much power a solar panel can produce if you think it requires a panel larger than a car to burn.

Watts are only a part of the equation.

You are also forgetting that your system has a capacity. By going around any of the normal charging wiring you are bypassing any overload protection. Which if left long enough can make a battery pop. That is why battery tenders that you plug into the wall cycle the charge so as to not overcharge and blow the battery.

actually, electricity doesn't care which way it "goes", so long as your battery tender's max power output does not exceed the fuse size on the otherwise unused wire while the car is sitting, the wire won't be able to tell the difference

This is sorta correct. If power is applied from one side it will travel either which way. However having power coming from both directions doesn't really work so well. This is why wire diagrams show you the flow of electricity on cars. It is designed to go in one direction. Going against that flow can cause serious damage. You have to also think how a wire is designed to handle X amount of power (in layman's terms) and is given Y power from it's normal source. Now you are asking that wire to also transport Z power back to where it's getting Y power from. This causes shorts or possibly burning wires.

Don't think of each component individually, think of the system as a whole. While the wire may not care which way power goes, fuses and relays do. Just like your cooling system really doesn't care which way the coolant flows, but the thermostat sure does as it won't really open if it's flowing backwards. Just because one or two things can go either way doesn't mean the system will like it on a whole.

 

[zzyzzx]

Clearly you don't understand how small 1.5watts is. Not 1.5KW, but a mere 1.5W

 

[foxtherouge]

Clearly you don't understand how small 1.5watts is. Not 1.5KW, but a mere 1.5W

Alright, ignore everything then. Have fun. I mean, it's only 1.5W right, they don't come in larger sizes at all right? I mean, I can't seem to find any larger than 1.5W. Not even one.

It's not like I have any experience in this matter right? I guess we don't use solar chargers in the army.

 

[Greasymechtech]

I run 5w-15w solar battery chargers/tenders and never had a problem. They need to be wired to pretty much ANY positive/negative continuously on wiring, or directly to battery....

If someone burned a vehicle to the ground, then that fool did something wrong. Military.. genius... hahahahaha oxymoron!

I've had a few cars have them connected permanently, along with boats, rvs, motorcycles, watercraft... over the years. Never had a problem.

Never connect solar panel directly to car wiring or battery. You must use a charger controller. This prevents the battery from overcharging. And, it prevents the panel from killing the battery at night(panel is a resistor at night and pulls power).

For example:

Solar Battery Chargers | Marine, Motorcycle, Aircraft, Auto, Truck

Battery MINDer’s solar battery chargers feature patented technology designed to safely reverse and eliminate battery sulfation.

www.batteryminders.com

Solar Battery Chargers

12V and 24V solar battery chargers will restore the loss of power and desulfate all types of lead-acid battery systems

www.pulsetech.net

12V 10W Solar Battery Charger Pro - Built-in MPPT Charge Controller + 3-Stages Charging - 10 Watts Solar Panel Trickle Battery Maintainer for Car, Motorcycle, Boat, ATV etc.

[Intelligent Charge] Innovatively built-in intelligent mppt (Maximum Power Point Track) charge controller chip, help to regulate the whole charging and generates at least 10%-20% more power than competitors. The three stages charging algorithm is improved to better charge and maintain battery at...

sunenergise.com

I can build my own kit for a lot cheaper with used locally found panel or one from harborfreight and any ebay/amazon 12v mini solar battery charge controller.

SunSaver MPPT - Morningstar Corporation

SunSaver MPPT, Morningstar Corporation, Solar, Charge Controller, 15 Amp, Maximum Power Point Tracking

www.morningstarcorp.com

100 Watt Solar Charge Regulator

Amazing deals on this 100 Watt Solar Charge Regulator at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

7 Watt Solar Panel Kit

Amazing deals on this 7 Watt Solar Panel Kit at Harbor Freight. Quality tools & low prices.

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1.5 Watt Solar Battery Maintainer

Amazing deals on this 1.5 Watt Solar Battery Charger at Harbor Freight. Quality tools & low prices.

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25 Watt Solar Panel

Amazing deals on this 25 Watt Solar Panel at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[foxtherouge]

SNIP FOR SIZE

Oh god yeah. I hope nobody was thinking of bypassing the charging module! I was hoping people here were not thinking of bypassing that. However having seen how "smart" some people in the world are....

Sadly the "intelligent" NCO that hardwired and burned his truck did actually use the whole component and just chopped the NATO plug off. Thankfully they weren't THAT dumb. I have met some people that are about as bright as a dead bulb in the military though.