Does length of wire to loads affect draw on battery?

[Geob]

I'm using solar to power a remote security camera and wireless transmitter. Below are the solar setup and the loads. We have experienced power problems and one question to which I can

[Sunking]

Does the length of wire from the solar controller/battery to the loads affect the power draw on the battery?

Absolutely yes. It adds resistance and thus lowers the current to the point where the device cannot operate

According to tables I’ve seen, my wire run of 200’ of #14/2 to my camera and transmitter is near the limit at which you get a 10% drop in voltage. Would increasing the gauge of this wire to #10 or #8 improve the performance of my system?

Yes but but it depends entirely on the current the device is drawing. However 10% voltage drop is way too much for a low voltage 12 volt system. At 10% running on battery only you are talking 11 volts and less at the device. As the battery discharges down to less than 10 volts at which point th edevice may fail to operate. But again note, the current, cable size, and length determines the voltage drop.

For example at 200 feet, 400 loop on #12 AWG at 2% voltage drop the max current you can run is .35 amps. That is not a lot. 2% of 12 volts is only .24 volts. So that means if your camera uses more than .35 amps, you run is too long for 12 AWG.

Easiest way to tell what is going on is measure the voltage at the source (battery), and again at the device (camera). Take the difference and see what you come up with.

[Geob]

I kind of ask the same question several different ways below. Thanks for your patience on this and my other posting while I try to get my understanding of this nailed down.

Our solar controller has battery protection which shuts power to the loads when the battery gets down to 11.5 volts. If we know that our devices operate fine to the point of this shutdown, would it still be worth increasing the size of the cables powering the devices? In other words, does the same device draw a battery down quicker if it is connected to a battery by 200’ of 14 AWG versus 200’ of 10 AWG?

My guess is that as long as the device is operating there is not a significant difference in power draw whether the cable is 14 AWG or 2 AWG. If I can determine that our devices operate to the point of the load shutdown at the controller, then it would not be beneficial to increase the size of the cable, is this correct? Or, even if the device is operating to the point of load shutdown at the controller, the greater decrease in voltage at the end of the cable run when using a smaller cable inflicts more wear and tear on the devices we are powering?

Thank you for your responses, I realize now that I need to make sure our devices will run at whatever voltage I should expect at the end of our power runs when the battery is at the controller shutdown point. I’ve been looking at this solely from the point that we are reaching the 11.5 volt shutoff point too quickly. If our equipment shuts down before the controller shuts off, we obviously need larger cable.

[Sunking]

[QUOTE=Geob;8902]
Our solar controller has battery protection which shuts power to the loads when the battery gets down to 11.5 volts. If we know that our devices operate fine to the point of this shutdown, would it still be worth increasing the size of the cables powering the devices? In other words, does the same device draw a battery down quicker if it is connected to a battery by 200

[Geob]

Look at the specs on the camera. You need to know a couple of things what is the minimum DC voltage the camera can operate on. What the current or power is required. Hopefully the voltage will say something like 10 to 16 volts. The number you want to pay attention to is the lower number and what the cable has to be designed for. If it say 11 volts you are screwed as that leaves you almost no room for voltage drop. If it is 9 or less no real problems.

Unfortunately I can't find the minimum voltage specs. Would testing the equipment using a power adapter with adjustable voltage be a good way to determine this (turning the voltage down until the equipment shuts off)?

Lastly your battery has to be large enough to carry all your loads for 5 days minimum, and your solar panel wattage must be large enough to replace what is used in a single day or more. The panel wattage is sized to the shortest day of the year in December and January.
Some simple voltage checks will tell you a lot, but you really need to know what your daily usage will be and th specs of the equipment. Otherwise you are likely to have a very frustrating and expensive learning curve.

We are using a 110 watt panel with a 110 aH rated battery and loads of about 25 amp hrs per day with a maximum of 15 watts. We were told a 4 day minimum would be fine, but I

[Sunking]

Unfortunately I can't find the minimum voltage specs. Would testing the equipment using a power adapter with adjustable voltage be a good way to determine this (turning the voltage down until the equipment shuts off)

Yes use a variable voltage power supply

We are using a 110 watt panel with a 110 aH rated battery and loads of about 25 amp hrs per day with a maximum of 15 watts.

Well the solar panel wattage and battery size sounds close to 4 days based on a 15 watt x 24 hour load.

Where is this located? Sounds to me like a voltage drop or bad connection problem.

[Geob]

15 watts is the load at night when the infrared lights comes on. During the day without IR, the camera and transmitter draw 9.48 watts.

This is located in the Virginia area. I've read that four to five times daily amperage need is recommended and that there is 4.5 hrs of useable sunlight in the winter.

What do you mean by "voltage drop" and how is it addressed? Is this the drop in voltage due to the long #14 cable power runs? Low voltage at the equipment means the battery has to work harder to power it?

[Sunking]

What do you mean by "voltage drop" and how is it addressed? Is this the drop in voltage due to the long #14 cable power runs?

Voltage drop is the voltage lost by current flowing on the conductors.

Voltage = Current x Resistance. So the more current or more resistance the more voltage you will drop. Like I said during the day take a voltage measurement at the battery, and another at the camera and see what the voltage drop is. 1 amp of cuurent, what your camera uses over 200 feet 1-way of 14AWG conductor should be dropping about 1.4 volts.