Solar panel question

[Chubb]

I have a solar panel that is rated at 64 watts and 16.5 volts @ peak.

Can I hook that directly to a 12 volt car battery that is used to power an electric gate?

I have been told that it may over charge that battery and more or less cook it but, the website for the panel is saying it's rated for a 12 volt battery.

I was planning to just go for it but, thought someone with some experience might be on here.

[PYBUCK]

Most 12v solar panels put out 18-20 volts. I would think 64v would overcharge it. What is the amp rating. Most 12v are 22]amps or so.

[Smart]

Most 12v solar panels put out 18-20 volts. I would think 64v would overcharge it. What is the amp rating. Most 12v are 22]amps or so.

65 watts at 16 volts is what he listed...

I'm not familiar with the wattage side but 16 volts is well within the normal solar panel range for 12 volt battery charging.

[dustoffer]

Amps = watts/volts, so this panel's amperage would be 64/16.5, or around 3.8 amps. Shouldn't cook a 12v car battery.

[Chubb]

Perfect!
Thanks for the responses!

[Roscoe]

Yes you could damage a 12v battery with a 12v solar panel w/o a charge regulator.


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[91cavgt]

Yes you could damage a 12v battery with a 12v solar panel w/o a charge regulator.


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I agree with this.


3.5 amps going into a car battery doesn’t sound like much, but a car battery is not designed to be recharged with that amount and only putting out a little power each day. Car batteries are designed to put out a lot of power over a short period of time, and recharged with a lot of amperage over a short period of time.

Can you hook it up for now? Sure. Will it work? Yes, but not for an extended period of time.

A simple 5 amp PWM(pulse width modulation) charge controller can be bought for less than $20 and will help to extend the life of the car battery.

Later down the road you could then upgrade the battery to a sealed AGM(absorbed glassmat) battery. With the AGM battery, PWM charge controller, and the solar panel you already have you will be looking at a low to zero maintenance setup for quit sometime.

[Hunter_Man]

Spend a couple bucks on amazon and buy a solar charge controller. I just wired two 170 watt panels to me sea container at my ranch as there is no power out there yet. Charge controller was about 40$ for me, but there are cheaper ones. It will ensure you don’t overcharge your batteries

[gonehuntin68]

I agree with this.


3.5 amps going into a car battery doesn’t sound like much, but a car battery is not designed to be recharged with that amount and only putting out a little power each day. Car batteries are designed to put out a lot of power over a short period of time, and recharged with a lot of amperage over a short period of time.

Can you hook it up for now? Sure. Will it work? Yes, but not for an extended period of time.

A simple 5 amp PWM(pulse width modulation) charge controller can be bought for less than $20 and will help to extend the life of the car battery.

Later down the road you could then upgrade the battery to a sealed AGM(absorbed glassmat) battery. With the AGM battery, PWM charge controller, and the solar panel you already have you will be looking at a low to zero maintenance setup for quit sometime.

This is the correct answer. Go to ebay or amazon and you will find them all day long for under $20.00.

[Chubb]

http://iallpowers.com/index.php?c=product&id=371

Like this one?

[LWolken]

Without a charge controller your solar amp/hr rating should not be more than 1% of the battery amp/hr rating.

Get yourself a Morning Star "Sun Guard" solar controller they are rated for 4.5 amps . They are potted so no water or critters can get inside.

[91cavgt]

http://iallpowers.com/index.php?c=product&id=371

Like this one?

That would be a little overkill but would do.

https://www.amazon.com/Sunforce-7-Amp-Charge-Controller/dp/B0006JO0XI

This one has been around for years. It’s not the best there is but is decent. Or get one like LWolken describes above.

[Chubb]

Thanks!

[Smart]

This is the correct answer. Go to ebay or amazon and you will find them all day long for under $20.00.

Rob I sent you a PM about a solar issue I am having.

[Draco]

It really depends on how many openings the gate will see in a day. Most of the openers come with a 5 watt solar panel. Occasionally I have to put a 10 watt on a gate to make the battery keep functioning. I don't worry about the 5 watt but when I go to the 10 watt then a charge controller is used.