How best to connect a power station to 'large' solar panel

[kgingeri]

Hi All, I'm in need of some advice...

Components to Connect:

I have a Canadian Solar panel (CS6P-230P) that gives VOC: 36V AOC: 8.5 - rated for 230 watt. OC measuring with a meter, the panel voltage in sun is 36.4 and amperage wise looks like 8.5 (I'm in southern Ontario, Canada - these are today's measurements). Here's specs for equivalent.​

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I am getting a "MAXOAK Power Station 500Wh 300W Bluetti AC50 Solar Generator" that is rated for "4-5Hrs to Recharge it Fully by a 120W Solar Panel".​

Another spec given is "Open Circuit Voltage(OCV):14-40V/Max.10A, Max.120W"​

Questions/Concerns:

My concern is that the panel is too large for the MPPT charger in this device - is this correct? My panel can put out 230W.​

Tho the "Open Circuit Voltage(OCV):14-40V/Max.10A, Max.120W" mentioned above falls within my panel output EXCEPT for wattage.​

Does the "Max 120W" mean that's the maximum the CS50 will use to charge, but it's ok to give more?​

Does it matter that the panel produces 36V and higher wattage or will the power station limit such?​

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Should I be putting a primary SCC on the panel and charge the power station via 12V input instead?.​

If so, how do I match a SCC? Would a "Victron BlueSolar MPPT 75/10 Charge Controller - 10 Amps / 75 Volts" be adequate?​

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How best do I connect these two? (This is for a camping setup, so I'm not concerned about equip close to spec, as apposed to future proofing etc.)​

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Thanks in advance!​

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PS: Not sure I understand how wattage and voltage plays for charging/input setups. I know most panels put out 18VDC and that's what a lot of devices are built for. So a bit uncertain if I can go on voltage and amperage alone or what? I know wattage load is whatever a device requires, but is too much on input OK?!​

 

[JTNYC]

You can simply connect it to the AC50. It'll just use what it needs and the rest will be wasted. It'll charge at around 120w. The AC50 can take up to 45V and your panel is below that so you're fine.

 

[kgingeri]

Thanks @JTNYC . In one of Will's videos, he explains charge controllers (@ 8:00) are rated by output, but I had a bit of a time understanding for sure.

 

[Positronium]

When solar cells are warm, the difference between the valence band and the conduction band (band gap) decreases. The electrons may be freed more easily in hot temperature, they do not carry as much energy.

At colder temperatures the band gap of solar cells is larger but there are is not as much current. 36V is bit close to the specifications upper limit. At cold temperatures the voltage may exceed solar charge controller limit. Charge controller tend to be much more sensitive to voltage limits as exceeding it tends to fry them.

I am suggesting to monitor PV voltage to make sure it stays within the specifications.

 

[kgingeri]

Thanks @Positronium - I can certainly monitor the system, once built.
It was about 3⁰ C (37ish F) today and nice clear skies when I tested, oh and about noon as well. So likely a good test. We'll be using it mostly in summer weather so that should help.
There's not likely a simple voltage limiter device, I'm guessing, at least not for 40V? Maybe I'll check and see what I can find. That would give me peace of mind at least.

 

[kgingeri]

Quick search turned up this:
LM2596 DC DC Step Down Converter Voltage Regulator LED Display Voltmeter 4.0~40 to 1.3-37V Buck Adapter Adjustable Power

Would this work as a safety for over voltage, or maybe something similar?

UPDATE: One on Amazon with better specs: DROK 6V-55V to DC 0-50V 0-5A Buck Voltage Regulator - tho 5 amp is likely too low.

 

[Positronium]

I don't think these smaller ones are viable as one can't really expect them to operate continuously near their limits. Do you intend to use buck converter between PV and MPPT? There would be conversion losses. I haven't tried it but you would probably need a buck converter that can exceed power of your 230W solar panel likely around 400W-500W.

 

[Forbisher]

Thanks @Positronium - I can certainly monitor the system, once built.
It was about 3⁰ C (37ish F) today and nice clear skies when I tested, oh and about noon as well. So likely a good test. We'll be using it mostly in summer weather so that should help.
There's not likely a simple voltage limiter device, I'm guessing, at least not for 40V? Maybe I'll check and see what I can find. That would give me peace of mind at least.

Even if your 230w panel exceeded the 40V max input on a colder morning no damage will happen to your Maxoak as it has a high voltage cut off that will protect it. It will display an Error code and have to be reset.

Your panel will output much lower Vmp not Voc except for briefly on those cold sunny mornings.

Dunno why all SCC do not have the same protection as the solar generators.

You are getting bad advice from people who know nothing about your Maxoak solar generator.

Your 230 watt panel will work just fine and max out the charging.

 

[Positronium]

I wasn't keen on using buck converter. I wasn't aware of the over-voltage on Maxoak SCC. That really does simplify things.

 

[kgingeri]

Thanks All!
@Forbisher this is excellent info! Thanks. I'll skip the buck converter then. This does seem like a pretty cool little solar generator. Fits the bill for our camping needs anyway.

 

[Forbisher]

Thanks All!
@Forbisher this is excellent info! Thanks. I'll skip the buck converter then. This does seem like a pretty cool little solar generator. Fits the bill for our camping needs anyway.

@JTNYC got it right on post #2

Strange that the 230w panel specs omit Vmp and Isc. Vmp is probably 30V?

Solar Generators are so passe. All the hip kids are making ugkly milk crate power stations. ?

 

[kgingeri]

@Forbisher I know, I know. But here in Canuck land it's a pain to order all the parts. Sometimes I can't even get them shipped here. Also, the nice neat package and warranty is nice. ?