Do You NEED A Solar Charge Controller??

All off grid solar panel system must have a charge controller. Here is why.

In this video, I will answer once and for all one of the most common questions I get asked in comments on my solar panel videos. The question is usually either "Can I connect my solar panel directly to my battery?" or "Do I need a charge controller if I am not going to use a battery?" (referring to directly connecting to an inverter).

The answer is yes! You do need one and with them only being $10-15 there really is no excuse not to have one. Watch the video for further explanation.

If you are looking for a good, inexpensive charge controller here is my recommendation:

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[donnasaunders]

Lmao, love it.. Thanks for answering my question. As I sit here with rum in hand, I wonder if I can charge my battery with just a solar panel. So.... I hook it up and have a multimeter hooked up to it to read voltage. I'm sitting on the porch while my baby plays in a bucket of water in the sun and my dog lay on the porch harding the public walkway. As it hooked up I search you tub for answers and you pop up and I take another sip of tea rum as I watch you speak. I love how toward the end you say if you want to baby sit your battery go a head and nock yourself out. 😆 as you say that I go to look at the meter to check the ⚡. I sit back down and knock myself out while enjoying my kid splashing and wondering what's what. Thanks man! I enjoyed your video. The battery charged safely. 😉

[chrishynes]

I have 2 controllers. One for the pre installed panel and another for the suitcase panels, could I eliminate one of these

[gloriamazibuko]

I have the charging controller, solar panel and battery but I don't have the wires. I would like to know the correct wires to use

[SailingTerra]

Will I need if I use lithium battery with a BMS.. The bms will manage the battery.

[fungames]

Do I need charge controller for my 17 year old car battery? My 4.5w panel is pumping in 60mA at 15V on a sunny day behind car glass and not oriented towards the sun. The car consumes 30mA to 39mA while sleeping.

[adamisaac]

If I’m planning to only sun power (not stored power) A battery isn’t a must?
I can just use the panel to the regulator and then the regulator to the inverter?

[jakehester]

Do charge controllers shut off at 14.5 volts or at all? This is what is getting me stuck...

[phillpauley]

I’m turning my van into a camper. Right now I have a 20 watt amorphous solar panel with a 7 amp charge controller that came with it hooked to two 12v 35ah batteries wired in parallel with a 1200 watt inverter powering a mini fridge. So far the fridge will only work for 8 hours at a time and it takes days to charge back up with the panel. I have recently wired the two batteries to the van’s battery with a cut off switch to charge while driving. I ordered two more panels to try to get it to charge faster. My question is, since I’m trying to run a fridge constantly do I really need the charge controller? Couldn’t I just install a blocking diode since the batteries don’t have a chance of being over charged? Any suggestions would be greatly appreciated!

[kenihow]

Can I use a voltmeter instead of a charge controller?

[manzoor]

Can we connect solar panel through solar controller 12v DC output and this output to 12vDc TO 220V AC CONVERTER 1500WATTS FOR RUNNING AC 220 FANS ETC. CAN THE SOLAR CHARGE CONTROLLER WORK WITHOUT A BATTERY WE DO NOT NIGHT POWER. OUR IS ONLY DAY TIME LOAD. OR WE MAY NEED A 10AH BATTERY, a small battery toboprationalise the charge controler

[JustinLodes]

One question I was curious about is why is the inverter always hooked up to the battery? How can the charge controller stop the battery from discharging if that’s how it’s wired? Why isn’t it just hooked up to the 12v load side on the right terminals of the charge controller?

[surgingcircuits]

Just adding that current grid-tie inverters can accept the panels directly as they can control and maximize panel input without the need for a storage device or additional voltage or current controllers. Cheers! Good video.

[lancecannon]

Do you need a charge controller to charge a battery is like saying do you need a 4wd to go off road well you can probably get away with going off-road in a regular vehicle but the vehicle might not last long and may leave you stranded

[immrnoidall]

i have one, 145 watt, 24 volt solar panel and two 12 volt, 120 ah deep cells, how many amps does my charge controller need to be? i have a cheap 10 amp, will that be ok?

[kokopelli]

Answer: a charge controller is a Charge Pump.
The necessity is highly dependent on the:
- loaded voltage of the panels
- chemistry and voltage of the battery
- current draw from the inverter.

Firstly the closer the panel and battery voltage to line AC the more efficient. Basically 12vdc is very inefficient unless using 12vdc appliances. 48-60vdc is much better.

LiFePO4 is more tolerant to slight overcharge and a BMS with High Voltage Cutoff will prevent overcharging.

Lead acid is best used in series to decrease Peukert effect, so 48vdc is common for low frequency inverters.

The charge controller raises the voltage from the panels at the cost of current, to a set point. Programmable controllers like the MPT 7210a are good for small projects. If the panels are closely matched to the battery packs like for example 40VMP to 39.6VDC(a123 BAE packs) then a controller isn't necessary so long as the current draw is moderated before the inverter.
I do this by daisy chaining battery banks.

[kdanagger]

The maximum charge voltage once the battery is out of constant current mode and switches to constant voltage is a matter of some debate. Some battery manufacturers say that 14.8 volts (or even 15.0 volts) is just fine until they are about 90% to 95% charged. At that point the voltage should be dropped to around 13.2 or so to avoid strong gas production and heating of the battery.
By increasing the voltage to 14.8 instead of 14.4, total charge time is noticeably reduced. This can be important with solar systems when it if often a race against the clock (sunset).

[joshspohn]

Not sure if this true but leaving solar panel hooked up directly to the battery at night will drain battery because the solar panel puts out infrared light

[bobwoerner]

i have 2 golf cart 6 volts connected for a 12 volt bank. they have sat for about a yr and current read 5, 38 volts. i believe this is to low for my mttp controller not yet installed to recognise to start recharging the batteries.i just bought a 100 watt solar panel .can i hook it up directly to the battery to raise the current 5.38 volts long should i expect to wait for the voltage to raise to a decent level for the controller to be added ?

[vLife]

I want to mount a specific flexible solar panel physical size (32 wide x 42 long) on my van.. in part because I want to benefit from the shade on my roof. The biggest wattage I have found is 200W 20v single panel. I am testing a Chafon 200WH (18ah) portable power station that has a built in charge controller .. I tested it with a 50w panel and it fully charged in about 6 hours. The back of the unit has a warning not to use a solar panel larger than 120w and/or 22v. Given that most panels don't yield what they say would this be safe to direct connect?

Also, if my real goal is run a fan in the van during direct sun light, anyway to regulate the 200w/20v panel so I don't need much battery but also so I don't burn my fan motor?

Odd idea, but if too much power for the Chafon.. can I just cover part of the panel?

My gut feeling is that connecting the 200W solar panel direct to the Chafon will be fine.. and that the 200W solar panel will never perform that well to be a problem.

[alaskanalain]

My panel puts out 18 volts but when connected it only produces 14 volts. I have a solar charge controller but don't use it yet since I only have one (smallish) panel. Another panel won't do much for me without another battery, also there is no space on deck anyway, so I would not need to use the controller anytime soon with my set up. The charge controller uses a bit of power to work anyway, it will be less efficient for my system. (sail boat) It has been going strong for many years. HOWEVER, can I connect a wind or hydro generator to the charge controller along with the solar panel or do I use a separate controller for each thing? Assuming the voltage is similar and the generators have their own diode.