Teardown Tuesday: Solar-Powered Floating Water Fountain

In this teardown, we examine the innards of a solar-powered floating water fountain by Feelle.

First Impressions

Feelle's Solar Powered Floating Water Fountain is a small, yet impressive, water fountain intended for a birdbath, pond, or pool and garden decoration. The diameter of the solar panel's disc measures about 6.3 inches; and while the thickness of the disc itself is about a ½ inch, the overall height of this little fountain is approximately 4 inches (from the bottom of the pump to the top of the fountain).

Other specifications, according to the included product specification sheet, include:

• Solar panel: 7V/1.4W
• Brushless (AKA BLDC) pump inlet: DC 4.5V-10V.
• Maximum quantity of flow: 150L/h.
• Maximum water height: 30-45cm (11.8-17.7 inches).
• Startup delay: < 3 seconds
• Restart: When sunlight is removed, the unit will restart within 3 seconds once sunlight is restored.

Before beginning the teardown process, I felt inclined to test (play with) this little fountain. After placing the fountain in a large bowl filled with water, once the sun found the solar panel the fountain began to work seemingly perfectly. Unsurprisingly, the angle of the sun's light onto the solar panel is directly proportional to the water's height. So obviously the fountain would work best on a cloudless day when the sun is directly overhead.

 

Feelle's solar powered water fountain. Image courtesy of Amazon.

No More Testing/Playing Around...Let the Teardown Begin

In reality, there's not too much to this design, at least that I could get my hands on (see the updated section below: "Removing the Potting Compound/Epoxy"). To ensure long-term reliability and to meet any associated safety standards, all the electronics (sans the solar panel array) are encased in a very hard potting compound/epoxy. This includes the pump and any associated electronics, and also the power conversion electronics (see image below).

 

All the electronics are encased in a potting compound.

 

I attempted to scrape away the potting material, but it was like scraping away concrete...not gonna happen! (Again, see the updated section below: "Removing the Potting Compound/Epoxy".) Given the total and complete encasement of the electronics, it doesn't surprise me, at all, that the IP rating of this device is IP68 (see image below).

 

The electronics being encased in a potting compound allows the device to be rated to IP68 (waterproof).

 

The electrical connection between the electronics and the solar panel is by pins/wires. Figure 4 below shows these connections connected to the solar panel, while figure 5 shows how these electrical connections are routed to the electronics. Take note that the electronics box was sealed to the bottom of the solar panel disc using some type of soft silicone—no potting compound was used here—so it was easy to cut through.

 

The area in the red box is where the solar panel array electrically connects to the electronics.

 

The electrical connections between the solar panel and the electronics box.

 

The only internal component that I could (initially) physically touch was the water pump's impeller. This inexpensive-looking impeller, along with its attached permanent magnet, is indeed the component that forces the water up and out of the fountain. As can be seen in the image below, this impeller simply slides inside the cyclical opening. There are no wires or any other electrical components attached to it.

 

The pump's impeller slides into the BLDC pump housing.

Removing the Potting Compound/Epoxy (Updated Section)

Author's note (added 12/11/2017): In response to one of our readers wanting more information, I went back to this teardown to really rip into the potting compound. The good news is that I managed to break into the encased components! Here's what I found:

With the hopes of removing the hard potting compound/epoxy, I boiled (in water) the epoxy-encased electronics, and then used screwdrivers, pliers, and vise grips to peel, scrape, pull, and twist off the epoxy.

During this process, I discovered that I was up against the clock. After boiling the epoxy for approximately five minutes, I had only about one minute to work with it (meaning to pry it off the electronics) before the epoxy hardened once again. During this one-minute window, the epoxy was a little less hard and somewhat pliable.

After cycling thru this boil, chip away at the epoxy, and then boil again routine (ten times) I was able to remove much of the epoxy. However, not surprisingly, some—by which I mean most and probably all—of the electronics were damaged in the process. The images below show the now-exposed electronics of this solar-powered water fountain, as well as the remnants of the removed epoxy.

 

The internal electronics of the voltage regulation and control.

 

• J1: This connector/these wires connect to the solar panel array
• J2: This connector/these wires connect to the pump
• Voltage regulator: No part marking
• Capacitor: Electrolytic, 47000µF, 16V, -40°C to 105°C
• MOSFET: Part marking: CMS 9475 1605. Similar to this MOSFET.

 

The internal electronics of the motor.

 

• Diode: No part marking

 

The bits and pieces of the removed epoxy and plastic enclosures.

 

Above you'll see the remains of the epoxy, my defeated foe.

Conclusion

It's interesting to see how the device is constructed using a BLDC motor along with potting compound to meet the IP68 rating, thus, making the device 100% waterproof. This device demonstrates what's required to make electronics waterproof (which, in this case, means a lot of stubborn epoxy). 

 

This article was updated on 12/11/2017 when Nick wrestled the potting compound off of the internal electronics. 

 

Next Teardown: Google Home Mini