Bill Smith Posted July 20, 2020 Author Share Posted July 20, 2020 (edited) Okay, I have a new idea, and I need you electronics math guys to help me: I'm thinking it's worth a try to go with a USB solar panel ONLY (sans battery), and connect it to the "pass-through" battery from the other test. That way, the panel can do its thing to fill the battery, and the battery can do its thing to pass on the power as needed. I'm thinking of trying this one: https://www.amazon.com/Lixada-Effiency-Activities-Lighting-Monocrystalline/dp/B071Z1LGFV I think that assuming the USB nano pump only pulls 5 watts, I would want a solar panel that provides more than that in order to charge the battery by the amount that was drained drained overnight, while powering the pump...maybe an extra 5 watts isn't enough. How would you decide? Edited July 20, 2020 by Bill Smith Link to comment Share on other sites More sharing options...
Bill Smith Posted July 20, 2020 Author Share Posted July 20, 2020 (edited) I took a look at this calculator: https://milliamps-watts.appspot.com/#:~:text=Convert Watt hours to mAh,milliamp-hours (mAh).&text=Formula is (Wh)*1000,* 1000 %2F 5V %3D 300mAh. It suggests that if a battery was given 5 watts from the sun over the course of 4 hours (20 watt hours), on 6 volts power (per specs on Amazon), that would produce 3333 mAh, which would just barely make up for the power lost from the battery overnight. Does this idea hold water? 😉 Edited July 20, 2020 by Bill Smith Link to comment Share on other sites More sharing options...
TheDukeAnumber1 Posted July 20, 2020 Share Posted July 20, 2020 (edited) Yeah you're on the right track. I forget how much power the nano pumps pull but I believe it's less than 5 watts, I will retest tonight and share. That solar panel may work but it does get mixed reviews about performing below the advertised wattage and I wouldn't want you to throw good money after bad. I'll do a little homework tonight to see what I can come up as far as how much power is needed and what components fit the project best. Is there a price point in mind for the total project that are you hoping to stay under? Edited July 20, 2020 by TheDukeAnumber1 1 Link to comment Share on other sites More sharing options...
Bill Smith Posted July 20, 2020 Author Share Posted July 20, 2020 2 hours ago, TheDukeAnumber1 said: Yeah you're on the right track. I forget how much power the nano pumps pull but I believe it's less than 5 watts, I will retest tonight and share. That solar panel may work but it does get mixed reviews about performing below the advertised wattage and I wouldn't want you to throw good money after bad. I'll do a little homework tonight to see what I can come up as far as how much power is needed and what components fit the project best. Is there a price point in mind for the total project that are you hoping to stay under? Thanks Duke. I'd like to stay under $50 for the whole project. This includes the $22 for the pass-through battery. Link to comment Share on other sites More sharing options...
DaveSamsell Posted July 20, 2020 Share Posted July 20, 2020 5 hours ago, Bill Smith said: Okay, I have a new idea, and I need you electronics math guys to help me: I'm thinking it's worth a try to go with a USB solar panel ONLY (sans battery), and connect it to the "pass-through" battery from the other test. That way, the panel can do its thing to fill the battery, and the battery can do its thing to pass on the power as needed. I'm thinking of trying this one: https://www.amazon.com/Lixada-Effiency-Activities-Lighting-Monocrystalline/dp/B071Z1LGFV I think that assuming the USB nano pump only pulls 5 watts, I would want a solar panel that provides more than that in order to charge the battery by the amount that was drained drained overnight, while powering the pump...maybe an extra 5 watts isn't enough. How would you decide? Hi Bill, Estimating on the high side, my Nano pumps draw about 150 ma or .150 Amps on average. So, if you multiply 5 volts x .150 Amps = .75 watts or 3/4 watt (not sure if you can see the decimal). Note: Each pump may vary, of course. Personally, I would at least double or triple the wattage requirement as a safeguard. In other words, a 2 to 3 watt source should be able to power the pump only, quite easily. 1 Link to comment Share on other sites More sharing options...
Bill Smith Posted July 20, 2020 Author Share Posted July 20, 2020 3 minutes ago, DaveSamsell said: Hi Bill, Estimating on the high side, my Nano pumps draw about 150 ma or .150 Amps on average. So, if you multiply 5 volts x .150 Amps = .75 watts or 3/4 watt (not sure if you can see the decimal). Note: Each pump may vary, of course. Personally, I would at least double or triple the wattage requirement as a safeguard. In other words, a 2 to 3 watt source should be able to power the pump only, quite easily. Thanks Dave. Yes, I had heard that is was generally under 1 watt usage. 1 Link to comment Share on other sites More sharing options...
TheDukeAnumber1 Posted July 21, 2020 Share Posted July 21, 2020 I tested a few and I was getting .02 amps at 5.19 volts, this is well under a watt. So the solar panel you linked above should be plenty but also the original unit should be working. My guess is this is a case of the "smart" circuits being not so smart. Will it charge a phone while sun is on the panels? I would consider a plan B of pairing that new panel with the nitecore F1 or nitecore F2 charger. They aren't water resistant but are inexpensive, made for this situation, and the battery can be swapped out. I have a couple I keep around for power outages and I like them. 1 Link to comment Share on other sites More sharing options...
Bill Smith Posted July 21, 2020 Author Share Posted July 21, 2020 3 hours ago, TheDukeAnumber1 said: I tested a few and I was getting .02 amps at 5.19 volts, this is well under a watt. So the solar panel you linked above should be plenty but also the original unit should be working. My guess is this is a case of the "smart" circuits being not so smart. Will it charge a phone while sun is on the panels? I would consider a plan B of pairing that new panel with the nitecore F1 or nitecore F2 charger. They aren't water resistant but are inexpensive, made for this situation, and the battery can be swapped out. I have a couple I keep around for power outages and I like them. Thanks Duke for the info. I ordered the panel, and will look into the Nitecore chargers. I definitely want to try the panel with my pass-through chargers from the other test. Will report back as soon as developments ensue! Link to comment Share on other sites More sharing options...
DaveSamsell Posted July 22, 2020 Share Posted July 22, 2020 On 7/20/2020 at 9:30 PM, TheDukeAnumber1 said: I tested a few and I was getting .02 amps at 5.19 volts, this is well under a watt. So the solar panel you linked above should be plenty but also the original unit should be working. My guess is this is a case of the "smart" circuits being not so smart. Will it charge a phone while sun is on the panels? I would consider a plan B of pairing that new panel with the nitecore F1 or nitecore F2 charger. They aren't water resistant but are inexpensive, made for this situation, and the battery can be swapped out. I have a couple I keep around for power outages and I like them. Hey Duke, Interesting. Was the test conducted with a check valve & under water? Also, how much air tubing was used, etc? The 20 ma of current draw really seems low to me. That is only about 100 mw consumption. 1 Link to comment Share on other sites More sharing options...
TheDukeAnumber1 Posted July 22, 2020 Share Posted July 22, 2020 (edited) 7 hours ago, DaveSamsell said: Hey Duke, Interesting. Was the test conducted with a check valve & under water? Also, how much air tubing was used, etc? The 20 ma of current draw really seems low to me. That is only about 100 mw consumption. I do think you're right. I know that that usb meter at least used to be accurate and .02 amps did strike me as really low but I was busy and didn't confirm at the time. I just now retested with a more reliable tester and got .9 watts at the outlet. So .9 minus any usb power supply inefficiencies and we are still under a watt of power. If I find a surplus of time I'll just splice the wire and get a straight reading with a multimeter under different loads. Edited July 22, 2020 by TheDukeAnumber1 grammor 1 1 Link to comment Share on other sites More sharing options...
Bill Smith Posted July 23, 2020 Author Share Posted July 23, 2020 Panel arrived. I will hook it up with the pump and pass-through battery after tonight's charge. Link to comment Share on other sites More sharing options...
Bill Smith Posted July 26, 2020 Author Share Posted July 26, 2020 So the panel with the pass-through charger was a non-starter. When sunlight hits the panel, the charger slowed down the pump power to get what it could from the sun. These things are just not meant to play together! I think a solar-powered air pump designed for this purpose is probably the best way to go, but I think I'll be running wire for my outdoor projects. 🙂 But, for me, it was still a useful test! Bill 4 Link to comment Share on other sites More sharing options...
Streetwise Posted July 26, 2020 Share Posted July 26, 2020 (edited) Thanks Bill, Duke, Dave, etc. I love seeing folks test and share ideas! Edited July 26, 2020 by Streetwise 2 1 Link to comment Share on other sites More sharing options...
DaveSamsell Posted July 26, 2020 Share Posted July 26, 2020 2 hours ago, Bill Smith said: So the panel with the pass-through charger was a non-starter. When sunlight hits the panel, the charger slowed down the pump power to get what it could from the sun. These things are just not meant to play together! I think a solar-powered air pump designed for this purpose is probably the best way to go, but I think I'll be running wire for my outdoor projects. 🙂 But, for me, it was still a useful test! Bill Bill, you have done beautifully. A lot of time and great effort. Thanks for both....... 🙂 1 Link to comment Share on other sites More sharing options...
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