Hi everyone,

I need help troubleshooting a water pump issue connected to my rainwater harvesting setup.

20W Solar panel positioned on old satellite dish mount

Using this YT video as a guide, I connected the 12V Duracell battery, solar panel, and water pump to the solar charger controller using 16 gauge wires.

PWM solar charge controller

This setup only worked for me on the first day. On the second day, it stopped working. Here's a video of me pushing the load button on the controller. I'm not sure what happened but the water pump will not turn on. I tested the voltage and I am getting a reading on the load and the solar connection. I'm not too savvy with electronic devices such as the solar charge controller so perhaps the settings are wrong? Do I have the right pump? Is the 20W Solar Panel too small? I have no idea anymore.

I thought this would be a very straightforward and easy DIY for my garden but I've been scratching my head for several weeks.

Any insight on this would be appreciated.

Comments

Diligent_Nature t1_is3uoq6 wrote on October 13, 2022 at 2:32 AM

Start by connecting the motor to the battery directly with nothing else connected. If it doesn't work the motor is bad or the battery is dead. If it does work then the charge controller may be bad. Read the manual thoroughly.

night-otter t1_is3zxev wrote on October 13, 2022 at 3:14 AM

Do you have a timer on the pump side or if the load comes live, its pumping its little heart out.

If the 2nd, then a 20w panel cant keep up. The controller is sensing low voltage in the battery and will not turn on the load. If you force the load on, the battery may not have enough juice to run the pump and just keep draining the battery.

If you add some sort timer that runs the pump for only 20-30 minutes in the morning. The solar panel has a chance to charge the battery the rest of the day.

lorfeir t1_is5pdab wrote on October 13, 2022 at 2:21 PM

If you don't already have one, I'd head down to the local hardware/homegoods/electronics shop and pick up a multimeter. First thing to try is to use the DC voltage setting and check the leads going to the pump when you think it should be running and verify that it's getting 12-ish volts. The main thing to figure out first is if the pump is burned out or if the problem is "upstream" of that.

I don't think you really have a problem with the solar panels or the battery, because it looks like from the controller display that your battery is fully charged to around 13 volts... which should be fine. But I'm making assumptions about what that display means.

Possibilities that occur to me:

The pump motor is burned out
You have a defective lead going to the pump (you can use the continuity mode on the multimeter to check that)
A transistor blew on the charge controller (one possibility is that the controller is not designed for driving motors... when a motor turns off, it can generate a big spike of power back to the controller... if the controller is not designed to handle it, it could damage the circuit).

EDIT: On the multimeter: you don't need a super fancy one. Even the cheapest should have DC volts and something to do a continuity check. A more sophisticated one will be more useful for other projects, but it's not like you need an expensive meter that measures down to the milliohm and can whistle the Star Spangled Banner.

brock_lee t1_is3w7in wrote on October 13, 2022 at 2:44 AM

There are a bunch of readouts on that controller (I have the same one) have you gone thru them all to look for any issues? Anything stand out?

anh_cloud9 OP t1_is47ado wrote on October 13, 2022 at 4:22 AM

Unfortunately I got this cheap one off Amazon with no manual. I'll have to search for them

Skunksta t1_is3xev6 wrote on October 13, 2022 at 2:53 AM

Any fuses connected? I put blade fuses on my 12v setups, helps narrow down any problems. Is the pump running constantly? If so what AH rating is your battery? I ran 100ah deep cycle batteries for my setup.

anh_cloud9 OP t1_is478f0 wrote on October 13, 2022 at 4:22 AM

Where do you put the fuse? Between battery and pump?

Skunksta t1_is4cv3o wrote on October 13, 2022 at 5:23 AM

I personally put blade fuses on all 3 connections. It might be overkill but works for me. If your battery is low amperage it may not be keeping up with the pump or the panel may not be keeping up with the demand on the battery.

Skunksta t1_is4cz0e wrote on October 13, 2022 at 5:24 AM

Also have a play with the buttons on the charge controller, mine is similar and if I remember correctly there's a constant on option or timer and some other options I never use.

Bdrodge t1_is53kpx wrote on October 13, 2022 at 11:22 AM

On some of the charge controllers the light output is only active when it is dark. The button is for how long you want the light on after dark. Cover the solar panel and see if it works.