Will this work?

Drizzt90

New Member
Joined
May 24, 2021
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16
I got a 100w panel from harbor freight and thought if it wasnt charging a big battery I could use it to charge devices or little battery banks through usb. My thought is
(1) 100w panel (https://www.harborfreight.com/100-watt-monocrystalline-solar-panel-57325.html) connected to (1) SAE adapter (https://www.amazon.com/dp/B07WCMX24L/ref=cm_sw_em_r_mt_dp_T3D1X6B34ADEKF6AKES9?_encoding=UTF8&psc=1) so I could put the wires into the controller (https://www.amazon.com/dp/B08NFSCZ4V/ref=cm_sw_em_r_mt_dp_PYMBED2Y79WS892H2C6V?_encoding=UTF8&psc=1)

The controller has usb ports that I would use to charge the devices/little battery banks.
I realize it’s a cheap controller but I didnt want to spent tons of money on it just yet. I’m up for suggestions on the setup if they aren‘t super expensive.
Thanks!
 

OnTheRoadAgain

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Feb 22, 2021
Messages
643
If the controller already has USB ports, why do you need SAE adapters ?

The USB ports may be powered from the battery, not from the Solar Panels, so your battery should be connected at all times.
It's not good to run a charge controller without a battery attached.

The peak voltage of that panels should be around 20v. Far above USB voltage so you cannot use it directly to charge USB.

I'm not sure I totally understand your goal here. But as long as you don't break any current or voltage rules, that SAE port should handle the 1 Solar panel voltage and current.
 

45North

Let it shine!
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Jan 2, 2020
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That controller works for 12 or 24v systems auto selected when you hook up battery first before panels.
What you are proposing is not ideal but might work. I don't see much downside.
You don't even need the sae adapter if you cut off the plug and strip the wires.
 

Drizzt90

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Joined
May 24, 2021
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16
I thought I needed the SAE adapter because the solar panel has SAE on the end of the cord that comes Out the back of it. To plug it into the solar controller listed in the post it looks like you cant just plug the SAE from the end of the panel into it. It needs the adapter to have the bare ends to go in those little clips on the controller.

My purpose was to use this situation for when I didn’t have a big 12v battery to plug into but I wanted to use the big panel to charge my small devices/portable battery banks.
 

Drizzt90

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Joined
May 24, 2021
Messages
16
Yeah I got a foldable Little 21w panel but I thought maybe I could use my big boy 100w panel to charge things if I wanted without connecting to a big battery
 

Drizzt90

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May 24, 2021
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I hesituate to cut off the SAE on the end because I need to use the SAE to Anderson adapter to plug into the back of my Duracell PowerSource 660
 

Substrate

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Apr 28, 2021
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Ok, so you've found out that SCC's need a battery to go with your 100w panel.

You already have a small solar setup now consisting of your 100w panel, and the duracell power station that has it's own internal little charge controller. Of course you can use the Duracell's own usb ports to charge your stuff, but you want to branch out. Fine.

That HF agm - sure, you could use it for general purpose, but to be honest, you'll be killing it prematurely like most people do with agm's.

What I would recommend instead is to use more modern equivalents like LiFeP04 where the proper maintenance and understanding of lead-acid is no longer needed. All you need to do with LFP is follow some very basic rules, and some of that is even protected by in internal electronic bms within the battery itself.

Consider this inexpensive LFP (LiFeP04) battery instead:

Miady LFP16AH

Is it top of the line? No. Just like an HF agm isn't either. But it is inexpensive enough and within the output of a 100w panel to charge it without damage (actually the internal bms is watching) using that SCC you mentioned. In that SCC, be sure to turn OFF temperature compensation. If turning it off is not possible, you can set it to +/- ZERO so basically it will have no effect. Those are lead-acid concerns.

(If you just want to do it without any hassle at all, pop for a 10amp Genasun GV-10 14.2v LFP controller, even though it costs more upfront. Aside from it being a well constructed controller, the fact that there are no choices to get wrong might be worth it alone for those unsure of what to do starting out.)

That will do fine charging up all your little stuff and allow you to get your feet wet. But it's not going to power your fridge, power tools, start your car etc. Well, not for long anyway!

It will keep you interested in learning more! You've got a road ahead, and this little kit will get you started in a more modern way than using a generic agm battery.

What it will teach you is that you can't just throw solar items at a wall and seeing if it will all stick. Finding out what DOES and what application it fits into is the best part. Now you won't be wasting money, or being tempted to throw away money by marketing sharks.
 
Last edited:

OnTheRoadAgain

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Feb 22, 2021
Messages
643
Thanks. But it is probably better to add something like this to the controller as you said it’s not good to do it without one on the controller too?

Yes. Solar charge controllers were designed to work with a battery. It's important to have one connected. That one will work.
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
2,704
So noW that you have a battery, is it sized good enough for what you want to charge?

Each USB jack will draw between one and two amps while charging A phone. If you have a long night and it charges all night, with one USB port, your battery will be lower than you might think, and using two charge ports all night would kill it. During a sunny day you should be fine, but on a cloudy day trying to constantly charge a couple of devices when the panel is producing 1 amp, but your devices need between two and four amps depletes the battery also.

I have a battery monitor and I see that while charging, each device Iplug in to charge pulls about .9 amps.
 

Drizzt90

New Member
Joined
May 24, 2021
Messages
16
Ok, so you've found out that SCC's need a battery to go with your 100w panel.

You already have a small solar setup now consisting of your 100w panel, and the duracell power station that has it's own internal little charge controller. Of course you can use the Duracell's own usb ports to charge your stuff, but you want to branch out. Fine.

That HF agm - sure, you could use it for general purpose, but to be honest, you'll be killing it prematurely like most people do with agm's.

What I would recommend instead is to use more modern equivalents like LiFeP04 where the proper maintenance and understanding of lead-acid is no longer needed. All you need to do with LFP is follow some very basic rules, and some of that is even protected by in internal electronic bms within the battery itself.

Consider this inexpensive LFP (LiFeP04) battery instead:

Miady LFP16AH

Is it top of the line? No. Just like an HF agm isn't either. But it is inexpensive enough and within the output of a 100w panel to charge it without damage (actually the internal bms is watching) using that SCC you mentioned. In that SCC, be sure to turn OFF temperature compensation. If turning it off is not possible, you can set it to +/- ZERO so basically it will have no effect. Those are lead-acid concerns.

(If you just want to do it without any hassle at all, pop for a 10amp Genasun GV-10 14.2v LFP controller, even though it costs more upfront. Aside from it being a well constructed controller, the fact that there are no choices to get wrong might be worth it alone for those unsure of what to do starting out.)

That will do fine charging up all your little stuff and allow you to get your feet wet. But it's not going to power your fridge, power tools, start your car etc. Well, not for long anyway!

It will keep you interested in learning more! You've got a road ahead, and this little kit will get you started in a more modern way than using a generic agm battery.

What it will teach you is that you can't just throw solar items at a wall and seeing if it will all stick. Finding out what DOES and what application it fits into is the best part. Now you won't be wasting money, or being tempted to throw away money by marketing sharks.
So... that controller and those batteries.
1. how many (or how do I determine) of those 100w panels can I connect to it?
2. I’m assuming you can parallel multiple of those batteries?
3. How do I get the juice out of those batteries? I didn’t see any USB ports or outs labeled that I can out to an inverter?... wait don’t I connect the inverter off the battery? If so and I have multiple in parallel does it matter which one I connect the inverter to?
 
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