Costco has a hundred watt foldable solar panel that supposedly puts out 18V. On a dollars per watt basis, it is not a great deal, but it is very easy to store and deploy, so I am willing to put up with the cost. (I already have a 120 W suitcase panel -- this new panel is for emergency use at home, as well as extra juice while camping.)My question, of course, is that I want to use this panel to charge a 12V battery. There has to be an after-market controller that will do the job. Given the specs of the panel (see link below), which controller do you recommend? Thanks in advance for your wisdom.Costco panel

profdant139 wrote:Costco has a hundred watt foldable solar panel that supposedly puts out 18V. On a dollars per watt basis, it is not a great deal, but it is very easy to store and deploy, so I am willing to put up with the cost. (I already have a 120 W suitcase panel -- this new panel is for emergency use at home, as well as extra juice while camping.)My question, of course, is that I want to use this panel to charge a 12V battery. There has to be an after-market controller that will do the job. Given the specs of the panel (see link below), which controller do you recommend? Thanks in advance for your wisdom.Costco panelAny PWM controller will work. Pick one for a simple setup like this, probably the least expensive one will work. Amazon has them as low as $10. A controller from a well known Mfr (Renogy) can be had for less than $20.

Not clear what the 18v DC connects to--does it have battery clamps? How would it connect to a controller's input?Says it has 3 AC outlets. So it has an inverter? It has all those adapters for your devices to go direct.You would need a 7.5 amp eg, as a controller if this were a normal 100w 12v panel (has 6.3a ISC some of them) since in time it could get the battery up over 15v. Suggest hands on view of this to see what connections it has --see the owner's manual--in the box (if it is not on-line somewhere) before buying.

WindyNation has a weatherproof PWM for $23.00. I used one to keep my wet batteries charged during storage for two years plus. Ten amp max. https://www.windynation.com/Charge-Controllers/Windy-Nation-Inc/WindyNation-Waterproof-10A-12V-Solar-Charge-Controller-w-LED-Charging-and-Load-Indicators/-/1981?p=YzE9MTc=

BFL13 wrote:Not clear what the 18v DC connects to--does it have battery clamps? How would it connect to a controller's input?Says it has 3 AC outlets. So it has an inverter? It has all those adapters for your devices to go direct.You would need a 7.5 amp eg, as a controller if this were a normal 100w 12v panel (has 6.3a ISC some of them) since in time it could get the battery up over 15v. Suggest hands on view of this to see what connections it has --see the owner's manual--in the box (if it is not on-line somewhere) before buying.I suspect that it already has some sort of charge "controller" built in since it mentions.."The Massimo Solar Panel is your newest commodity to camping and hiking. Constructed from high-efficiency monocrystal silicon solar cells with efficiencies up to 23%, convert more solar power into usable energy. 5V USB and 18V DC dual outputs keep your USB/DC devices fully charged. This solar panel is environmentally friendly, practical, and convenient for emergency power supply situations. The Massimo Solar Panel comes with 10 adapters to charge phones, cameras, laptops, Massimo power stations and much more. Make sure you're prepared for the next adventure with the 100W Massimo Foldable Solar Panel. "The ten adapters look suspiciously like the same kind of adapters used on universal generic laptop power supplies which set the voltage and amperage output for the laptop you have.. 18V is pretty typical for most laptop chargers..Adding an external charge controller to this panel without bypassing or rewiring to get around the built in 5V/18V device may result in pretty lack luster results.

Gde, my main concern isn't lackluster performance, although that is certainly relevant. The big issue is that I don't want to cook my 12V battery with an 18V panel!

Costco 100W 18V solar blanket: which controller to use?

pianotuna
Nomad III
Jun 22, 2022
BFL13 wrote:
Apparently nobody watched the video I linked back when.

Hi BFL13,

I watched it.
BFL13
Explorer II
Jun 22, 2022
Apparently nobody watched the video I linked back when.
pianotuna
Nomad III
Jun 22, 2022
profdant139,

A good decision.
profdant139
Explorer II
Jun 21, 2022
Well, after all that, I am going to return the panel to Costco. All of the connectors are dinky little metal tubes, the kind you'd use for powering a boom box. (I'm showing my age here.)

So the way I figure it, if the manufacturer of this panel thought that this unit could charge a real 12v battery, they would have included some hardware (maybe alligator clips??) that would attach to the battery terminals. But they didn't.

Bottom line -- I might (or might not) be able to get it to work with enough add-on hardware, but it is not worth the "sunk costs" of the hardware. I can easily return the panel to Costco -- but it is not so easy to return the hardware for a full refund.
pianotuna
Nomad III
Jun 21, 2022
profdant139 pwm controllers do not drop the voltage. They operate at what ever the battery voltage is. As the battery gets fuller the control "pulses" the power, with shorter "on" time and greater "off" time. PWM does include a one way diode to prevent the panels from drawing power from the battery bank.

110 amp-hour battery flooded? Then with this panel under PERFECT conditions 5.5 amps are going into the battery. But that only happens around solar noon.

I would be comfortable doing direct connection to the battery with an on/off switch between the panel and the bank.
2oldman
Explorer II
Jun 21, 2022
I can't find specific specs like with 'normal' solar panels. Open circuit voltage is normally 18v or higher, but when hooked to a load like a battery that voltage comes down. But, I can't say for sure if 18v is open circuit.
BFL13
Explorer II
Jun 21, 2022
How do you connect that 18v power wire to the 31 battery? or even to a solar controller that then connects to the battery?

You might have a power station that you charge up with that like in the video, and then use a battery charger plugged into the power station, but that seems a bit much.
profdant139
Explorer II
Jun 21, 2022
Very useful comments -- thanks! If I decide to keep this panel, I would use it to charge a group 31 deep cycle battery, with 110 amp/hour capacity.

My existing 120 watt panel fully recharges my battery every day -- we carry a spare battery but never need it! (And yes, we carry a generator, also never run it.)

So this new 100 watt panel (if it works with a 12 volt battery) would just add to my existing charging options.

And yes, it is clearly too expensive on a "per watt" basis -- but it folds easily, it is very light, and it is easy to store. Those are important considerations, especially since our trailer is so small.
pianotuna
Nomad III
Jun 20, 2022
Hi,

How large is the battery bank?
BFL13
Explorer II
Jun 20, 2022
It works with a power station, as seen in this video. It is not a "normal" solar panel.

https://sterlingwong.com/2022/02/05/review-costco-massimo-100-watt-solar-blanket-folding-solar-panel/

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Costco 100W 18V solar blanket: which controller to use?

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