Charging a Car Battery with a Solar Panel and Charge Controller

If you connect a solar panel directly to a car battery, it will eventually overcharge the battery and damage it. That's why you need to use a solar charge controller. This is my own design using the latest microcontroller and MOSFET circuitry. It consumes less than 1mA (that's very little) and has a neat little blue LED that tells you the battery voltage. It can also be connected in various different configurations so you can do clever things like charge two batteries from one solar panel. You can get the PWM5 from www.256.co.uk

[@user-nm8nf7jk2z]

*The solar **Generater.Systems** E300 is a great product . It does everything well. Great job, Jackery.*

[@briana171994]

Making use of the kzbin.infoUgkxcJ22tnHH9l1vjdIdEIG27iOG55P7LXI8 reconditioning plan, I just saved 2 auto batteries from being completely junked. The guides were very simple to follow. I wish I would have found this years ago! You may use the guide to recondition any battery type

[@riaanleroux5017]

Thank you! Exactly what I wanted to find out. perfect, basic yet to the point.

[@KunalVaidya]

Thanks for sharing and explaning why directly we shouldn't connect battery to solar panel. 14 years later too this video is clear and is giving good information. I am planning to use a 55w 12v mono perc panel and a PWM solar charge controller for making a trickle charger for my car. it parked most of the time and gets discharged

[@JulianIlett]

The charge controller protects the battery so you can leave it set up like this permanently. You can also connect an inverter to the battery (and use it). You can also start the car engine. Everything can be left connected up.

[@In_the_name-of_ALLAH]

Small system with car battery kzbin.info/www/bejne/nqSwdmSwpKiWjck

[@MrHermangv]

Thanks I have some parasitic electricity draining my EX rig’s batteries, instead of finding it am adding solar to it lol I have to much shit hooked up to it, it could be anything at this point at how old the ex is

[@keishadholmes9796]

What will be the fasted way to charge a car battery using solar panels and how many watts of a solar panel do i need to fully charge a car battery ?

[@denoc817]

Basically saying the battery is dumb. It doesn't know how to stop charging if directly connected to a solar panel of any size wattage. By using a charge controller to charge a battery, the charge controller regulate the proper voltages to charge a battery. Then shuts off when it is fully charge. Just like a smart charger would do.

[@kingofthecrows8802]

A simpler way to think about it is like this. The battery, or storage device, is regulated to draw and receive up to 12v. A solar panel of that size will likely give more than 12 volts so to charge the battery safely, a circuit is put in-between the two connections to prevent the battery from receiving too much power. Too much electricity at once will cause the battery to overheat and meltdown.

[@solderist]

Very simple and short video yet very informative. Good for those starting to learn about solar charging. Thank you for this video sir

[@JulianIlett]

If your country has plenty of sunshine, a solar panel is a great way to keep your battery charged. If you use a small panel (less than 10W), you can connect it directly to the battery, but a bigger panel will need a charge controller to prevent damaging the battery.

[@aakudev]

Hello, thanks for the video. I have a Q, i just want to keep my car battery topped up as my running is low. Mine is a 45ah Amaron battery, would the below spec solar panel without controller be ok to just keep the battery from draining? : Max Power(Pmax): 5Watts Max Power Voltage(Vmp):8.7 V Max Power Current(Imp): 0.58A Open Circuit Voltage: 11V Short Circuit Current: 0.62A Tolerance:± 5% Weight: 0.2kg

[@JulianIlett]

Wind generators need a system that stops them running too fast when the battery is fully charged and not taking current. Either a shunt type charge controller (which shorts out the generator) or a controller with a dump load (which diverts current to a dummy load - often a heating element) must be used with a wind turbine. My controller is a series type (which goes open circuit when the battery is full) so it only works with solar panels.

[@JulianIlett]

Standard techniques are peturb and observe and/or hill climbing. The maximum power point moves around - it's not fixed like a regulated output voltage voltage. What interests me is whether the maximum power point coincides with maximum battery voltage. If it does, the design could be so much simpler. Thanks for the interesting question.

[@JulianIlett]

Sorry, I didn't really answer your question! Solar is almost certainly going to be more effective than wind unless you live on an isolated farm on a hilltop. Domestic scale wind turbines are notoriously ineffective, generally because they're not placed high enough. No-one's going to be very pleased if you put a wind turbine on top of a 100ft pole in your back garden. Having said that, there's a small marine turbine (50 to 100W) attached to a nearby house which always seems to be spinning.

[@johnnieveight4925]

Very informative to us novices starting out, thank you.

[@richardcalderon1483]

Pwde po bang e seres ang solar battery at car battery

[@JulianIlett]

Yes - just like in the video. Solar panel, charge controller, battery, fan (add a switch if necessary).

[@JulianIlett]

Let's say you use an 80W panel and that you get 5 hours sunshine a day. You could run that 800W appliance for half an hour. Factor in losses, and you might get 20 minutes. 800W at 12 Volts is 67 Amps so that's about 24 Amp hours. So the battery should be at least 50Ah.

[@JulianIlett]

Unlikely. The switching device is a MOSFET which is more likely to go open circuit in an overload condition. If the software freezes, the charge pump stops running and the MOSFET will turn off. Also, a watchdog timer reboots the program. There are a number of safeguards against this happening.

[@JulianIlett]

If the battery is large and the panel small you probably don't need a charge controller. But a small battery (like a small SLA gel battery) could still be damaged by a 5W panel.

[@andyp9131]

Your right it would take many hours like a full week before it gets anywhere near to. Damaging the battery . The battery is miles bigger than the small solar panel I have a 30 watt solar manner charger and my battery has never been damaged so I think u would need to leave it on a whole week to damage the battery as the solar panel is not powerful enough to damage the battery . I've been charging my batteries now for around 4;year's I only leave them on for around 12 hours that's all

[@JulianIlett]

Fascinating question. MPPT only applies during the bulk charge phase, absorbtion and float require regular PWM with battery voltage monitoring. MPPT seeks to maximise solar panel power, so you need to measure panel voltage and current and multiply them together. A standard buck converter regulates output voltage, but that's not required for MPPT so you'll need a non-standard DC/DC converter - you may have to design it yourself. You'll need to find the maximum power point which isn't fixed.

[@JulianIlett]

The PWM5 controller handles 6A so can be used with solar panels up to 100W. You will need crocodile clips, cable, connector block (chocolate block), connectors for whatever is on the end of the solar panel cables and optionally a fuse.

[@JulianIlett]

If the kit has silly little solar panels (1 or 2 Watts), you probably won't need a charge controller (unless the battery is also very tiny). If it has a proper solar panel (10 Watts or more) it should be supplied with a charge controller or you risk damaging your battery. The charge controller fits between the solar panel and battery - you don't need anything between the battery and the inverter.

[@JulianIlett]

A certain amount of bubbling is good - it stirs up the acid preventing layers of different strength acid forming (stratification). Excessive bubbling is undesirable because water is lost during the process. Charging voltage can be high for a while to speed up charge absorbtion, then the voltage should be lowered to minimise gassing and consequent water loss.

[@majestic-skies]

Finally a video that explains this in plain english lol Thank you!

[@jasonmorgan661]

My panel is just 12 volts from a electric fence system. It won't get above twelve but it will bring it up to at least 8 or 9 volts which is good in a jam.

[@goSaifulgo]

How long does it takes to charge the battery?

[@JulianIlett]

36-cell solar panels (the type designed to charge 12v batteries) have an open circuit voltage around 22 volts, easily enough to overcharge the battery. Why the high voltage? So that they also work when the sun is low in the sky or obscured. 14v solar panels are not common (you'd probably have to make your own) and would only work under full sun.

[@moosesnWoop]

this was awesome - 2010 no less!

[@In_the_name-of_ALLAH]

Small system with car battery kzbin.info/www/bejne/nqSwdmSwpKiWjck

[@JulianIlett]

Four 12v batteries in series gives you a system voltage of 48 volts. I only work with 12 volt systems.

[@getnowbestsavingdevice2298]

Ohh so that is why... I really need to buy a solar controller.. thanks for sharing this...

[@yodadundar8308]

Nice to see you responding with courtesy, name calling just shows you have issues and can't give positive or -ve feedback without abuse

[@JulianIlett]

PWM5 controller from website mentioned in the video description - connectors from eBay

[@sandrapanico6357]

Where can I get one of these? I just forked over a chunk of change to replace my dead car battery. Great concept.

[@JulianIlett]

The panel in the video is 20 watts, but I'm using bigger panels now. The PWM5 controller can handle any panel up to 100 watts. Yes, you can leave the panel connected via the controller to the battery indefinitely.

[@RoyerRogers545]

How many volts is the panel?

[@JulianIlett]

I'm just seeing a poor match between the low power of the solar panel and the very high consumption of the water heater. Either use more solar panels or use a lower wattage heater.

[@Landrew0]

Very basic but useful advice.

[@kathyjohnston613]

julian i also have the battery hooked up to a inverter which wasnt turned on at the time thanks kathy

[@JulianIlett]

Only if the solar panel is small - 5 Watts or less.

[@bryanleggo3489]

I'd like to use a solar panel on the roof of a van to charge a separate battery just to power a fan at night. The purpose is just to cool the car enough at night so I can sleep. It doesn't have to be a car battery - a smaller one would do. Do you know of a way to do that?

[@yugo130]

I just use a smaller panel that puts out about 30 ma. The battery doesn't get overcharged that way. 30 ma is more than the normal drain of the accessories in my car.

[@paulsmi55]

Be careful here...this video is potentially misleading. If you consistently charge at anything less than 13.8V your battery will suffer slow death by sulfation and lose capacity. Nor is charging to 13.8v ideal. Make sure your charge controller takes the battery to around 14.2 V and then reverts to a float charge of 13.8V thereafter.

[@funzosupport6922]

thats not correct either, my agm 12v battery likes 14.8v, and this is fine anything over 13v is charging

[@mickcarson8504]

LOL. Too many Brainy in here, no Brawny. Each to their own knowledge bros.

[@firefly4202]

could the charge controller ever fail in away that the battery would get direct current again from the solar panel

[@lipevolcom2]

It's a nice battery desulfator right ther if stills at 16v at low amp like this 10w panel u will be saving a lot of money reconditioning old batteries and saving money not even need to buy a desulfator device!

[@olumideasenuga9498]

I really find this useful. Very useful and easy to follow. But what's the the red and black clips cable called? It will be nice knowing what it's called before going to look for it

[@Pabkojdim]

Hello im very interested in your video I guess you got to see it to believe it. My one question is how long can you leave it in that setup for? And if was to hook up an Invertor to the car battery is it possible to use the battery while in that setup? I have all the supplies needed just need the reassurance to proceed.

[@maximaleffort]

Thank you! Cheers mate.

[@JulianIlett]

You're wrong. 13v is a safe voltage to hold a lead-acid battery at. Also, solar power isn't constant - the sun disappears every night for a few hours.

[@JulianIlett]

Let's say you discharge the battery 33% per day - that's 50Ah = 600Wh @ 12V. Now let's say you get 8 hours sunshine a day - 600/8 = 89W. De-rate the panel a little to allow for transfer losses and I'd recommend a 100W panel. If you take less energy from the battery each day, you can use a smaller panel.

[@1bike2up]

why do you say at 14v it's bad for the battery ? when a battery is being charged from your car alternator it hits that voltage

[@juandef4115]

Your car also feeds from that though reducing that. Ubless you akways drive with no stereo or aircon on etc

[@zoltan8600]

Battery charging voltage anything between 13.8V-14.4V(14.7V some of new cars )

[@keishadholmes9796]

What will be the fasted way to charge a car battery using solar panels and how many watts of a solar panel do i need to fully charge a car battery ?

[@jivantakirstenpillay6128]

I have heard it is safe to connect this way using a 1.5Watt Trickle charger and wont hurt the battery.

[@JulianIlett]

Yes it can - see my video "Charging Two Batteries with one Solar Panel"

[@dwightstewart7181]

What if the battery is connected to a significant load? For example, a continuously running motor. In this case, to get maximum going into the battery (to offset that load), wouldn’t it be better to simply not use a charger?

[@GunMan303]

I have a this exact set up after watching this video I went out and got all of the items shown here even the little male and female power connectors. I have a car battery that is a bit low only about 11v so i plugged in my panel and charge controller and waited all day for it to be charged at like 12.5v so I could use my inverter on the battery. But this set up dose not seem to work it dose not charge the battery I have asked others and they tell me this whole set up is wrong! please advise!

[@stevesealey317]

Do you have to remove the battery caps when charging like you should when you use an electric battery charger.

[@tommyboy7820]

Thanks for sharing

[@flatisland]

if the voltage of the panel drops below the charging voltage can it get damaged by the battery?

[@GospelTruth37059]

Would you need a charge controller for trickle solar power charger as well? I am new to solar energy panels.

[@johnnjen5118]

Could you use the solar panel to run a alternatir system that charges the batteries that are in use? An if so would i need a batter for the alternator system. Also would i need a surge protector/30min apc between the batteries and the appliances?

[@laser204]

Can you plug a 110v power supply into this to charge the battery instead of using a solar panel? I’m making a Bluetooth speaker and I need to be able to charge the 12v battery that’s built int the box

[@Devoneakapimp]

What rating solar panel should I use to make a portable generator connected to a marine deep cycle battery and inverter to power a 800 watt appliance?

[@maximumwoof]

good scare ! :) use a charge controller as the 'middleman' !

[@nitram_nosnibor]

Can anyone help with this question please. In my off grid workshop I have a 100w solar panel going through a 20A controller and into a 12v 130ah battery, that’s working great. On the controller I also have a LOAD output that I have going to my lights, what I would like to know is if I can split that output and feed it into my motorbike battery to keep it topped up. When I look at my charger that I have used that plugs into the house power socket, it states Output 12v / 800mA. If I can feed a cable to the LOAD on the controller and to the bike battery, will it act as a trickle charge or what will happen once the bike battery has fully charged? Or will I need one of these PWM5 type of extra controllers? Thanks

[@abdulasrarr]

thank you..but i wanna know how many watts of solar panel should i buy to charge my 150ah battery...and as u said i will use charge controller... i live arid regiongs do i dont have to worry about sunlight..:)

[@zamfully]

Can one go from a charge controller to the lighter

[@SpeedManiac1976]

i have a battery trainer for car battery at home and i have a 12v to 220v converter for my sigarettelighter in my car, if i hook the battery trainer to that converter in my car while driving does it recharge my battery then ? i think so but not sure, been thinking about these solar pannels as well didnt know about that charge controller, very usefull video !!!

[@JulianIlett]

It won't work. Unless you're planning to run the 'heating appliance' for no more than a minute every hour, you won't have enough power. Also drawing 3.5kW from any 12v battery will destroy it pretty quickly.

[@12ock]

if you have 8 solar pannels and 10 car batteries.... in your home and that device like breaker... is it possible to operate your home... when you consume 24hrs of aircondition, and refrigerator or is it farfetch...

[@legallimitoutdoors9917]

What size panel r u useing? Thank u. 👍

[@Farmer2492]

Hi I am going to buy a 120 watt to 200 watt solar panel to put on my camper trailer would I be able to use the charge controller also would the solar panels keep my battery charged and can I just leave the charge controller on so when day light comes it will start charging again what I used during the night. Regards Farmer

[@MisterKibz]

So basically how to solve it? should i use a boost converter or current transformer to hike up the power to a suitable value before inverting it? or any idea u would suggest to solve this project? thanks....

[@simonethomas5777]

If using a solar panel to charge on maintain your vehicle, would you have to take it off at night

[@titlematchboxing]

How long will it take to charge the battery with this setup?

[@wojciechtechtips1602]

Amp hour of the battery ÷ solar panel amps = hours of charging Ah - A = Hours

[@JaimeSilva]

can you tell what happens when the battery is fully charged and you still have the charge going in?

[@bhanu4k]

Can a Lipo battery charged and discharged at the same when connected to solar cells via buck booster

[@markhorney7625]

What type of solar panel you got there mate. Brand and model?

[@slybunda]

would this work in a car thats not used often? would the alternator cause problems for this setup when the car is started and the voltage rises to 14.4v?

[@denoc817]

With a good charge controller it is built with smart technology protections. It will accept 12 to 24volts charges 1.5amps or 50amps or higher. The controller will regulate according to the voltages it detects. Not over feeding not under feeding.

[@denoc817]

The answer is No. But consider how you plug the batteries in Parallel Positive to Positive, Negative to Negative. Combining 2 batteries. Which read the voltages as 1 battery. The other means of connection is in Series which will joint 2 battery together to read 24+- volts. So that is said. How you connect the Positive and Negative cables from the charge controller will determine the rate it charges and which battery will charge first ur both charge at the same time.

[@MisterKibz]

Julian, im doin a solar water heater project where im using solar panel to charge the current for my water heater appliance.A heater consume power is 3.5kW so i plan to install 50W panel to car battery with controller in middle and an inverter to convert the dc to ac current for heater appliances,it is good enough or u would suggest some better rating for each component? also, it is ok to use car battery as shown above rather than deep cycle battery for long term as im using solar panel project?

[@Bahraini0]

Hi, I don’t know why my battery is not changed fully.

[@12vLife]

What if your battery were connected to your car and alternator? Any danger/risk? Does that charge controller have a diode to keep the panel from draining your battery at night? I have this 200watt, 18v, 6amp max flexible solar panel I want to mount on my van. I would like to install a 20amp charge controller that has 2.4v USB ports built in. But I have a 4amp 12v fan Id like to run during heave sunlight.. but I've been told I need a stead 12v source.. Can I use my vans 12v 70AH 120RC primary starter battery as part of my simple solar setup? I don't anticipating ever draining the battery below 11v.

[@drrobotnikmeanbeanma]

What's the fastest way to solar charge a car battery ?

[@velcrodingleberries]

Would I be able to charge several deep cell batteries in consist, connected to an inverter for an off grid system with this device?

[@fishing540]

How many watts is the solar panel thanks

[@micjakes1]

Are these available in America? Here we have battery doctors or keyline isolators.

[@crashredistrict]

Hello mate ,what do you think about ??? Please reply ,not sure is the best choice or not ,either damage the battery or is ok . I own a 2014 3 series diesel 2.0 . Battery is flat only need to start the engine AA Solar Panel Battery Charger 

[@enriquesalgadoaceves9017]

juliannnn! very gooood, can you please send me the link for that specific charge controlet, I. a big fan.

[@parjacpar3077]

I managed to over load battery even with charge controlled wired in would it be because i didnt have a dump load wired in ?

[@MultiHeavyD]

Ok lets say i bought a battery. Used Alot of its energy bought one of these pannels hooked it up nd it wud fully charge so its like new????

[@JulianIlett]

Google's translation is "No, that would be stupid to break ammeter poked, all would have been clearly".

[@lweber6999]

So i can leave this setup in my camper for over 6 months?

[@chucknorris1988]

So what happens to the excess energy once the battery is full but the PV panel is still generating a current?

[@TheXigeneral]

you can always get a controller or dc step down

[@lweber6999]

What is the life expectancy of the controller. And is it a catastrophic failure or simply a dead battery.

[@abdulasrarr]

i live in places where there is power for just 4 hrs a day..so itsn't enough to charge my battery which is connected to my ups... can i charge it using solar panel?? mY battery is a 12v leadacid With 100AH ..PLS REPLY

[@user-ef5qn9js6f]

I already did that directly does my battery not working anymore

[@skullrazor]

Can I connect the solar panel directly to the battery if the battery holds very low charge, then later add the charge controller when the battery charge is high enough?

[@In_the_name-of_ALLAH]

No

[@ralphposadas1412]

How many watts is your solar panel and how many amps does the solar charge controller put out into the batter?

[@carolynwilliams7828]

I have a wind turbine and solar panels also 5 batterys,just pluged into shore power and the batterys are reading 14.8 but they are bubbling.is that safe?

[@JulianIlett]

eBay. Search for "CCTV 2.1mm".

[@jfcrock372011]

Why dont you attach the solar pannel to the car like the roof and then you never have to plug it in anywhere instant charge?

[@ZBBeats954]

just to let you know 14.6 volt is not going to destroy your battery i can see around 15 v but not 14.6

[@CasualsXe]

With this setup, will I also be able to run an inverter off of the battery at the same time? I plan to use it to power my ponds pump (0.3Amps, 115V, 400GPH) so I don't have wires running everywhere

[@danielthomas1589]

Chris Espinoza then just pick up a solar powered pond pump there like 20 bucks on Amazon

[@christopherashurst4610]

my solar charger is 12v 1.5w and my car battery is a 650amp battery do i need a controller for this