Misting Irrigation Solar Sadness

[wdbone007]

I work for a non-profit organization in California, and most of our work is done either in-house or pro bono. I really appreciate the gathering of minds, and I feel like I have come to the right place!

We have a 'green'house that is irrigated by a cistern that harvests rainwater and feeds out into a 1/2" irrigation hose which leads to a 12v water pump which is connected to a timer box that is set to kick the relay on for 1 minute increments every hour and half during daylight hours. The timer box is connected to a solar regulator that is connected to a 12v solar panel and a 12v battery. As you may be able to tell from the pictures, the charging light is on. This light only comes on during daylight hours, and it is the only light that comes on. The weak charge light (red) and full charge light (green) have not been on since we first got the battery (probably had a full charge when we got it). As you might also be able to see in the pictures, the timer box is disconnected in order to try to allow the battery to store up a charge. My theory is that if we had another solar panel and/or we hooked up a second battery, the battery would get enough energy from the panel to actually hold a charge that would be capable of sending the 12v's needed by the timer box/relay. Am I on the right track? I apologize if my terminology or nomenclature is off. Everything I know about solar panels, I learned in the last week or two!

Dry in California,

William

[inetdog]

I work for a non-profit organization in California, and most of our work is done either in-house or pro bono. I really appreciate the gathering of minds, and I feel like I have come to the right place!

We have a 'green'house that is irrigated by a cistern that harvests rainwater and feeds out into a 1/2" irrigation hose which leads to a 12v water pump which is connected to a timer box that is set to kick the relay on for 1 minute increments every hour and half during daylight hours. The timer box is connected to a solar regulator that is connected to a 12v solar panel and a 12v battery. As you may be able to tell from the pictures, the charging light is on. This light only comes on during daylight hours, and it is the only light that comes on. The weak charge light (red) and full charge light (green) have not been on since we first got the battery (probably had a full charge when we got it). As you might also be able to see in the pictures, the timer box is disconnected in order to try to allow the battery to store up a charge. My theory is that if we had another solar panel and/or we hooked up a second battery, the battery would get enough energy from the panel to actually hold a charge that would be capable of sending the 12v's needed by the timer box/relay. Am I on the right track? I apologize if my terminology or nomenclature is off. Everything I know about solar panels, I learned in the last week or two!

Dry in California,

William

Welcome to Solar Panel Talk, William!

If your panels do not produce enough power for your daily use (with a margin for bad weather), then adding more batteries will just kill more batteries.

If you can temporarily connect up a line powered charger you can see whether the batteries are still usable.

You need to calculate the actual power used by the timer/valve system and make sure you have enough panel wattage to serve it.
If temporarily disconnecting the load does not allow the panel to recharge the battery in a few days, you have a fault in your equipment somewhere.
It is possible for a panel to degrade in a way that still produces normal voltage (and therefore turns on the charging light on the controller) but no longer provides enough current to be useful in charging.

[wdbone007]

Welcome to Solar Panel Talk, William!

If your panels do not produce enough power for your daily use (with a margin for bad weather), then adding more batteries will just kill more batteries.

If you can temporarily connect up a line powered charger you can see whether the batteries are still usable.

You need to calculate the actual power used by the timer/valve system and make sure you have enough panel wattage to serve it.

temporarily disconnecting the load does not allow the panel to recharge the battery in a few days, you have a fault in your equipment somewhere.

It is possible for a panel to degrade in a way that still produces normal voltage (and therefore turns on the charging light on the controller) but no longer provides enough current to be useful in charging.

I actually left the load disconnected all weekend to see if there was any way to get the battery charged up. When I went out to check it today, it did not have ANY lights on. Not even the charging light was on, even though the panel was in the sun. The charging light usually kicks on around high noon. Is there any way to test how much wattage is coming out of the solar panel? I know that it is a 12V panel, but I cannot find anything to indicate how much wattage there is. How do I calculate wattage? Is there a way to test these things without going to the hardware store and buying the sensory tools (voltometer, etc.)?

[inetdog]

Is there any way to test how much wattage is coming out of the solar panel? I know that it is a 12V panel, but I cannot find anything to indicate how much wattage there is. How do I calculate wattage? Is there a way to test these things without going to the hardware store and buying the sensory tools (voltometer, etc.)?

Simplest thing in the world to make a very quick and dirty check. Get an ammeter that can handle up to about 20A DC.
Cover the panel and connect the ammeter leads to the two panel leads (without the battery connected!!!). Now uncover the panel.
The current you read is called the short-circuit current, I_SC. If you multiply that current times the open circuit voltage, V_OC), and then multiply that by roughly .64. That will give you the maximum power output of the panel in its current condition.
Cover the panel and the reconnect everything if the numbers look right.
Also (set the meter back to volts!) measure the battery voltage.
Let us know what you get and also the approximate dimensions of the panel in inches.
You can get a ballpark on the rated power of the panel by multiplying its area in square meters (sorry about that) by between 100 for a poor panel to 200 for an incredibly good panel. Yours will probably be on the low side of that.

If there is a nameplate with output numbers on the panel, let us know what they are too.

[wdbone007]

multimeter acquired

Well I went back to the shed to see if we had any sort of an electric monitoring device, and I did find a multimeter. Can a multimeter be used the same way as an ammeter? It looks like it can but I don't have any sunlight to test it with. Thanks again for all your help.

William

[inetdog]

Well I went back to the shed to see if we had any sort of an electric monitoring device, and I did find a multimeter. Can a multimeter be used the same way as an ammeter? It looks like it can but I don't have any sunlight to test it with. Thanks again for all your help.

William

A multimeter will include a milliamp measuring function, and may also include a 10 or more amp AC or DC capability. But to use the high amp range almost always requires plugging one of both of the leads into different sockets on the meter and you should not try that setup unless the instructions are clearly written and you are sure you understand them.

[Mike90250]

Most charge controllers require a working battery to "boot themselves up" and monitor the solar. If your battery is so dead, that the controller is not running, you will
a) need to verify the controller is working, BEFORE you plug a new battery in.
b) figure what caused the controller or battery to die in the first place.

[Wy_White_Wolf]

My feelings are that whoever designed the system got it out of balance. Because of that the solar panel is too small for the battery and load. never fully charging the battery has sulficated it loosing it capaicity.

To know for sure we need a few more details.

1. Load. Amps/watts of the pump and power consumption of the timer.

2. Battery size and type.

3. Solar panel size watts/VMP/ISC

3. Charge Controller size make and model.

WWW

[wdbone007]

some answers that may lead to more questions

My feelings are that whoever designed the system got it out of balance. Because of that the solar panel is too small for the battery and load. never fully charging the battery has sulficated it loosing it capaicity.

To know for sure we need a few more details.

1. Load. Amps/watts of the pump and power consumption of the timer.

2. Battery size and type.

3. Solar panel size watts/VMP/ISC

4. Charge Controller size make and model.

WWW

1. Pump: 12 Volt DC / 110 Watt ; Timer: 12V activation requirement to switch on relay but has an internal battery that it keeps time with and uses as a backup.

2. 12V 9AH AGM Sealed Non-Spillable Battery: Werker Batteries - WKA12-9F2

3. 12V, 15W, 21 Open Circuit Voltage 36" x 12"

4. QUICK Solar Powered Charge Regulator Part No. 800310-001. Solar input: 7A max. Over Charge: 14V +/- 0.5V.
Over Discharge: 11V +/- 0.3V max

We are experiencing a 500 year (according to tree rings) low in rainfall in this area, and today it is raining. Thank God for the rain, but it is not conducive to my output testing that I was planning on doing today. Also, my multimeter is a
CEN-TECH 7-Function Digital Multimeter, and I have no clue how to use it...

[Naptown]

That meter will do
You will when doing the short circuit test switch the red lead into the hole just above where it is plugged into in the photo and set the dial to point at 10A

Disconnect the battery and let it rest for about 4 hours and do a voltage test on that (you can do that today)
When the sun comes out do the other tests.
If the battery is dead <10.5V charge it up connect the controller then the panel to the battery in that order and do the other tests.

[wdbone007]

PUMP: picture 1

[wdbone007]

PUMP: picture 2

[wdbone007]

Battery

[wdbone007]

Regulator

[wdbone007]

setup