Harbor freight solar panel review/test..Can this small solar panel charge a car battery??? 

Just an update on the solar panel I cut the blue led in it and it seemed to help charge the battery faster. It was stuck at 11.90 for a few days I cut the blue led and its went up to 11.92 now

This panel can put out close to 100 watts ru-vid.comUgkxOqI2yqX0XVrhR2BMJciTWrHJpG8FhJyg when positioned in the appropriate southernly direction, tilted to the optimal angle for your latitude/date, and connected to a higher capacity device than a 500. The built in kickstand angle is a fixed at 50 degrees. Up to 20% more power can be output by selecting the actual date and latitude optimal angle.The 500 will only input 3.5A maximum at 18 volts for 63 watts. Some of the excess power from the panel can be fed into a USB battery bank, charged directly from the panel while also charging a 500. This will allow you to harvest as much as 63 + 15 = 78 watts.If this panel is used to charge a larger device, such as the power station, then its full output potential can be realized.

I have one of these panels, and in my driveway it puts out 19.5 to 20 VDC on a sunny August day. I tilted it to the South at about 45 degrees. I am in the Sierra Nevada at about 1200 ft elevation on the 38th parallel. If I decide to try to use it as a 12 V battery charger, I will install it with a solar charge controller to limit the voltage output to avoid damaging my batteries by boiling out the electrolyte.

Interesting was thinking of getting one from Amazon or eBay. Didn’t notice these at Harbor Freight and it already has the same plug as I put on my battery already. I’ve installed these on military trucks before and they worked surprisingly well.

I thought I would just throw my two cents in on this conversation. I think this charger works great. I had a guy who was working on my truck for a year and every time I go over the battery would be dead and we have to jump it or charge the battery. It was a brand new interstate battery and the truck has an internal drain somewhere. I don’t drive this truck very often so I threw one of these Harbor Freight maintainers on the dash and Hooked it up through my cigarette lighter. It hasn’t been driven in five months but when I go and start it up it’s got full energy on the battery. If anything it might be overcharging it a little bit. No I haven’t tested the battery or tested the energy coming out of it but when I start the car and the starter is spinning at an extremely high rpm I know the battery is fully charged. My only gripe is it’s got two suction cups that you can stick on the glass windshield and they suck. It eventually falls off after two or three weeks. But I leave it on the dash and it works fine. I went and started the truck two days ago there was no direct sunlight just reflections and it has a little blue indicator light when there’s power going through it and it was blinking. So I can give it five stars.

Awesome, hey thanks for a comprehensive review on this solar panel.

I use this one to keep my 13V supercapacitor bank fully charged. Works great. It was 13CAD 5 years ago

ITS ONLY TO MAINTAIN CURRENT BATTERY LEVEL not to charge. Great review.

Excellent post, thank you for sharing.

These freaking things are AMAZING!!!! Got battery box from Walmart.. hooked it all up w lighter port and +- post. Used it for trolling motor battery which was main propulsion for my 16’ boat. Used it on camping trips and never lost battery. Mine was amazing.

All of the voltage measurements of the battery were taken with the panel attached, so you were reading the voltages of the panel and battery combined. A real test would be to take the panel off, then measure resting voltage, which should be at or above 12.6v. The 100w kit will get you there much faster, then you can use this little panel to keep it topped.

I used to put 2 on the battery on my sailboat and every 2 or 3 days would go to my sailboat which was moored off 79 st in Miami. And was able to use my car cooler fan I had rigged up to keep me cool all night about 6 hrs. Really charge better than when I had only 1 solar charger. Free Energy 💯

I have a similar solar charger, I'm in the UK, so not that much sun. I find that the charger does not provide enough to keep my infrequently used car topped up. However, I have a spare car battery in the house, the solar charger does provide enough to keep this topped up. i.e. the charger does make up for the self discharge of the battery.

1.5 watts will take forever but it’s an amorphous panel and actually not bad ... mono crystalline panel will charge a lot better in lower light especially overcast/cloudy days

at about 5:30, you tested with the charger still connected? not a legitimate test...

They also sell a bigger one that's like four times this size. If you need more of a charge. These are not really made to charge a battery, just to keep it at the right level if you have a slow draw like a clock on a stereo in a side by side or golf cart.

I bought the same panel.... I started to use it on a battery in a camper that is in storage outside. I called Harbor freight to get some clarifications. I was told by the level two tech that I should not use this charger without a voltage regulator ... that they sell for 21 dollars .. more than the cost of the solar unit... because the solar charger can put out up to 23 volts when its in full sun... the 23 volts can damage a 12 volt battery... the amperage is very low but I dont want to damage my battery so I took it off. If I used a regulator it might only be useful as a trickle charger to maintain the battery...... I dont think it has enough output to really charge a battery... it can only maintain a fully charged one.....im continuing to research this problem but this is what i have learned so far

They work great . I got one keeps my parked car ready to go all the time even after sitting for long period of time . the car is 30 over years old .

I was # 1000 Likes! LOL I "Like" doing that! Thank you for the video... and Update.

Thank you! Much needed

This charger... Story: My Tahoe's "On-Star" tried to connect without a break overnight, draining my battery so that the door locks, windows, lights, buzzer... Well... All dead. Battery dead. My buddy came and picked me up and we went to Harbor Freight, bought one I came back and put it on the dash, plugging it in to the dash power source. No jumping the battery, I just wanted to see what it could do. In 3 hours my truck started right up like it had a full battery. I have since bought 8 more as gifts to my family and church member friends so they don't get stranded anywhere. It works in lower light it cloudy days but at only about 30% to 50% of what direct sunlight does. I suppose your "back and forth" probably has to do with the fact that it's made in China by unskilled laborers and sometimes substandard materials. My experience: All 9 that I bought work like a charm. Worth the money, Absolutamente.

I used this solar panel today. I started with 12.31V, and about 4 hours later it was 12.49V. It was sunny most of the time then cloudy. Even with clouds, the LED light was blinking. The battery is a Dyna-batt, dry cell battery. I'm not sure if that matter; just wanted to add that as an FYI.

My blue light isn't flashing anymore and my controller says low voltage. I'm wondering if leaving the solar panel flat wasn't the best idea and water got in the panel.

I've been using a similar model of panel to this (no LED) in Australia for a few years. They definitely work. If you don't drive everyday, then they are very handy. I had to get the cigarette lighter changed to 'live' so that I could use that to charge with rather than the battery terminals. I originally mounted mine inside the rear window as I parked on the street, but now it's been outside next to the garage for 2 years. I bought an extension lead from eBay for a few dollars to reach outside the garage. Due to the colder climate in my new place and not being able to mount in the best position it hasn't worked as well. The car battery was bought new in Nov 2013 (nearly 8 years old), previously I was only getting 2.5-3 years tops. I bought an AC trickle charge recently and they are very handy too. If you test your battery after a few cold winter days and find the volts are 11.8-12.0 (and you can't start), then 2 minutes with the trickle charger and it's good to go. There's a also a repair mode that removes some of the buildup in the battery which improves the charging. If you live in a cloudy, cold climate in winter, and/or you can't mount it in the best position, I would recommended getting a higher capacity panel than the 1.5 Watt of this one. But otherwise, they do a good job of preventing flat batteries.

can you romove the charging clamps & retest the battery?

I used mine throughout the winter. After I am done cutting I reconnect it. Hopefully I can get a few more years out of my riding battery.

Wondering if it’s waterproof. I bought several for equipment that sets long periods at a time. Tested myself. Seems to help if it will last

Now I'm wondering if I run this through a buck converter and output at 5v how well it will charge a phone or other USB accessories.

I bought this same one, my problem was that when I left it hooked up to the cigarette lighter at night, it drained my battery! Also, would it be better to hook it up with the cables directly to the battery? And do I take it off at night and on rainy days as well? Thank you!

If you truly want to test it and not waste days waiting for results just use your ohm meter on "current" setting. You'll see immediately if any current is going from the panel to the battery.

Is it possible that people are using the cigarette adapter and they turned the car off so that basically disabled stop so you don't have like your GPS or cell phone charger that basically depletes your battery overnight because you forgot to unplug it

Mr. Kososky, yesterday I went out and bought the Thunderbolt Solar Panels. I hope to use them to power my 100 watt ham radio with a battery. I have other uses such as the battery charger for the lawn tractor.

Oh yeah, I like what you are doing. Lots of guys like me need some basic teaching, and you are a wonderful mentor. Be my friend, okay? Seriously.

Just want to point out that a "Good" discharged battery will naturally recover some after it is disconnected from even the slightest draw, which can be influenced by the many components in the vehicle circuit. I'm fairly certain that's what happened in this video. Not saying that these don't work (I just bought two), I just think an overcast day will not allow them to perform at the full 1.5A potential, not even close. I plan to do an amperage test during an overcast Florida day, and then compare this to results from a blistering Florida day. I have hope they work, but not much hope that these will maintain four deep-cycle boat batteries. I hope I'm wrong.

I bought the 5 volt yesterday from Harbor Freight to trickle charge my RV battery, but...I cannot for the life of me figure out how to connect the wiring to the panel. The panel itself looks like it has a USB connection, and all the wiring ends look like yours. Thoughts?

You should disconnect the solar panel when checking if it got charged.

You could also add a few capacitors to improve the start ability

I have one of these 1.5 watt chargers hooked up to an old jumpbox that I Jerry rigged some LED strobe lights to run on my landscape trailer. They don't draw very much power. I use them maybe 5 hours a day twice a week. As of right now I only pull the solar panel out of my tool box to charge the battery while I am using it to work. I have yet to have to recharge the battery any other way. I have to figure out where on the trailer I can find a more permanent mount for it so I don't have to really worry about it pulling it in and out all the time or worry about a dead battery. Altho I might get a bigger panel if I decide to do that.

Can you leave this outside in the weather?

This solar panel works good if you keep it in good sun light. I used it to charge the dead battery in my Dodge. Took about 4 or 5 days.

Maybe do a video where you measure the drain over 48 hours and then what the charge is over 48 hours. Least then you'll know. I was housebound for years and used my car only once a month and one of these was enough to offset the drain (which was just the clock and ecu). Depends on the car I guess. Newer cars have more of a drain than older ones. My solar charger connected via ODBII also which was handy as my cigarette lighter didn't work :) Good video.

I used two panels, hooked up in parallel, to increase current rating. Ran my lead acid sealed battery down to 10v then hooked up the panels. Took about 5 days to bring battery up to 12.3v. So, yeah, I suppose it would work in keeping battery topped off.

Mine works for maintaining my batteries. I might get another one too.

I'm not an electrical engineer but I would have to say that working on tvs has taught me the component called Zener diode would be a good start to seeing any results if you had a charged battery and were going to leave it hooked up overnight.

Just purchased the 1.5 Watt Solar Battery charger from Harbor Freight. I want to use it to keep our RV battery charged while the RV is in storage (up to 8 months). The instructions recommend that we use a voltage regulator. Do you have a recommendation for a regulator? Thanks for creating the video - it was helpful.

Get 30 of them and tie them together to the same circuit. Now you got power!

Couple things to remember when using a trickle charger the charger you used only supplies 1.5 watts if the car is draining more than 1.5 watts then you will not charge the battery just slow down the discharge of it, also these chargers seldom hit their quoted wattages so a 1.5 watt may only deliver 1.2 watts or less, also with the cigarette lighter most newer vehicles have auto disconnect of the cigarette lighter after about 15 minutes so any charge going into them is wasted, might be the reason for the high number of people that say they don't work

Yeah, In all fairness, if this was just used to keep a battery topped off at all times, then you don’t need anything else or need to worry about how fast it charges a battery, even if it is just 1 or 2 volts. Some times small vehicles such as a golf car or a riding mower just sit unused and something like this is handy to keep it charged enough to allow you to confidently startup each time it is required. You don’t always need something that can charge a battery in two hours.

What if you used 2 of them ?

Now if your cigarette lighter is wired to go off when you turn the key off it will not charge the battery. You do not want to leave the key on just to charge the battery but you can wire another one straight to the battery or use the clips. I think that's why some people are saying it doesn't work. I use mine all the time to

What tupe of conector do they use? What are they called and wonder if they make a cellphone adapter for it to use for a cell phone

Nice

I’m thinking about trying to set this up on a storage unit to maintain my motorcycle battery. Are the wires long enough to attempt that?

I'f you open the panel you can cut the led out and get a lil bit more current

Remember. It just maintains. I have a coleman unit. It works great for what it is. I use it to maintain the battery on my 5x10 trailer. I have a small winch on it.

Just curious so after a year is it still chargeing well , or have you had to replace it ? Thanks for the upload btw

i used to have 6 of these 1.5 watt panels 3 in each back window on a 2003 dodge durango going to the car battery to trickle charge it worked great to keep the battery up when i was running my mobile vhf 35 watt radio when not running the car i had seperate panels on the roof rack to a reap battery independent and that was a 200ah battery ran my off road lights 2 50 watt panels from china

How could the charger stay connected to the battery when the instructions state that the charger could be damaged if connected when starting the car?

Thinking of getting one of these or the schumacher brand from oreillys for my f150. With gas being over $4 a gallon and only 10mpg not the best. Just wanted to see if woukd be worth it since my truck only goes out like once every few weeks to month

DO YOU PUT YOUR TESTER ON DC TO CHECK THE ACTUAL SOLAR CHARGER ALLIGATOR CLIPS??

The first one I brought from Harbor freight worked great for a couple of years until the sun’s heat finally melted the wires at the solar panel. The second one didn’t work straight out of the box. I’m going to take the solar panel back to HF tomorrow!

I believe you could splice 2 of the panels together and charge the battery a little faster. This gauge wire should be able to handle the amperage.

It just maintains the battery voltage. Not really a charger. I use one for my plow tractor and back up generator. Just bought the 25 amp thunder bolt going to see if it will actually charge a battery this weekend. But you do need the controller so you don't cook the battery.

i tried mine. & haven't seen a light? where is it? THANKS!

I put one on my 03 s-10, with some undefined parasitic draw.. Sits for up to a week in between starts.. Charger seems to be helping a lot..

My vehicle battery jump-starter (the portable thingie that jump-starts your car) has a slot like a car's cigarette lighter does. Would this thing power my jump-starter so that I could use it as a power bank? My jump-starter also has a micro-USB slot, so I can charge small devices such as a phone, headphones, LED camp light, or speaker.

cool stuff... does it have a charge controller built in it to prevent overcharge ?

The light is LED( light emitting diode) which is a one way diode so by cutting it, you battery would drain at nigh and flow goes backwards.

I'm sorry for my stupidity ignorance but why would you want to plug it into your cigarett Lighter what does it do after you plug it in

Get a monocrystaline 50watt. Get a solar charge regulator or buck converter pcb and set to 13 volts max on it's screw setting.

I think it could be described like a trickle charger, not a full battery charger.

They are mostly a battery maintainer (ie) as vehicle that is in Storage. I just put mine on the dash board for the winter and it keeps the battery up all the winter. I have them in 3 vehicles threw the winter months. Not sure about using the cigarette lighter thing though. I looks more like an UTV not a golf cart,!!! Just my 2 cents

Hey Chuck will it charge from lights shining in an underground parking lot?

I don’t understand how plugging that into the 12v would charge a car battery

How does the cig lighter attachment work? Seems counter-intuitive that you could input power through such a port?

Chuck there is a solar cell phone charger that I just bought and reviewed, called the Carga "Blob." Mine is the 800 mAh. I do not know if it is for sale in the USA cuz I bought mine here in Mexico. If it is, could you do a review on it? (Mine cost me just over $20) Thanks. God bless. Edit: March 2021 I have bought 8 of these Blob chargers. Recently, I've seen a YubTub ad about them that they're "On Sale" for $75 plus shipping. Holy Molé. That's 4 times what I paid for mine here in Mexico. They work well, for the most part, but we had a bad run of them, and 2 of the last 3 would not hold a charge and Coppell did allow us to exchange them. So I'm holding off buying any more until they fix the problem.

1.5W :12v= 0,125 A , 75Ah: 0.125A=600 hours 600h: 24h= 25 days

We had an old gasoline powered forklift we would use 4 or 5 time a month. Always had to bring a battery charger. Hooked one of these up and it always fired up.

Good thinking for putting the solar panel on top of your ATV: closer to the sun…

So, it seems to do a good enough job to keep the battery level high, without having to run the engine every once in a while. That works for me as I have sunshine 90% of the year.

More solar panels may increase the voltage on the battery quicker.

Will this charger work through the cigarette lighter on a 2002 Dodge camper van?

I'd be worried about this thing overcharging a battery if left on?

I bougth solar battery maintainer 7.5 watts on amazon keep my battery charge ...i have a parasite drain battery keeping my baterry draing during nigth but this solve my proble problem temporarily ...dealer wants $1000 for bcm replacement this solar panel make the job no mater itis a cloudy outside

Little things that may improve detergent the LED light disconnected and uses power that will boost your milliamps a little. Number two solar panels put current into a battery. But when the charging gets too low oh, and a current will reverse and go to the solar panel. At act like the little red diode draining the battery. So disconnecting the battery at night would prevent that. Do a little research and you'll see that solar panels are diodes any M Image a low-level light that you cannot see, which causes a drain.peracetic

It works well because is not designed for such big battery as yours... Here in Greece now summer time, out is about 32-36C, with exactly same solar (different brand) it gets 21V output direct from the panel ... So at this high voltage connected direct to the panel has charged a 4 year old 12V / 4Ah moped 50 cc bike drained battery from 9.1 V to 12.3 V with in 3-4 hours ... winter time out 14-18C at bright day it gets output about 14-16V .... winter time tested to charge a drained 12V / 3Ah from 8V it needs 2-3 days to reach 12+ Volts ... So it works for me only fully sunny days, how ever note this is a charger to maintain capacity really & not charge, only hot countries may benefit to charge fully small bike batteries ... EDIT apart a nice sunny day, HEAT also matters on these solar panels

Nice. Is it waterproof so I can leave it on the roof on my UTV?

does it work with lithium batteries?

At 1.5 watt, you want to take it apart and remove that LED. The power such a solar panel makes is all used by the LED. But people need fancy things right. An LED like that can drain a fully charged battery in 30 days. It defeats the whole purpose of a small solar panel to keep an idle system topped up that time instead.

Will this need a solar charge control ?

any worries about over charging?

That battery is very flat should be over 12.5 would take several hours to charge off mains

At 1.5w by 12v it would take 1 year to fully charge

Should have tested the battery as soon as you hooked it up

This seems like it would work for me. I have a car with a parasitic drain that is a pain in the ass. The battery is new and the alternator works fine, its just dead every 8-12 hrs of sitting. This would be alot cheaper, mentally and monetarily, than paying someone or trying to fix it myself. My brain just doesn't work that way. Imma get me one of these. thanks.

If the battery is flat it’s not gonna charge it it’s mostly a trickle charger

So if I’m running a 12 volt water pump should I run this solar charger while I’m using the pump?

It is a fact that this will NOT even maintain a battery on a vehicle. Vehicles do have some parasitic drains to keep the clock and ECU powered. I had one of these on vehicle that I only moved across the streed twice a week and this did absolutely nothing to help it. The current is just simply too low to even keep the battery charged. The battery was low and It was fully charged my a charger and ran for years after. This is a waste of money. I didn't cut the blue LED so I don't know if that would have helped but it didn't work.

But you didn’t start it?

cant be used without a regulator, these pumpout 20+ volts and destroy batteries without that regulator, yes i just learnt this myself after playing with them years ago