What is the optimal distance for wiring between my charge controller and my battery? When does a significant voltage drop occur? - Phocos (2024)

FAQs

What is the optimal distance for wiring between my charge controller and my battery? When does a significant voltage drop occur? - Phocos? ›

When does a significant voltage drop occur? It is highly recommended that the charge controller be within one meter (approximately 3.25ft) of the battery bank and in the same room or enclosure. Be sure all rooms and enclosures are well ventilated.

The charge controller regulates this 16 to 20 volts output of the panel down to what the battery needs at the time. This voltage will vary from about 10.5 to 14.6, depending on the state of charge of the battery, the type of battery, in what mode the controller is in, and temperature.

Most common charge controllers have an output voltage of 12V, 24V or 48V. The input voltage and current ratings are typically up to 60V and up to 60 A, accordingly.

Factors such as cable size and type, voltage drop, and temperature affect the distance, and the general rule of thumb is that solar panels should be no more than 100 feet away from the charge controller. However, this can be extended by using larger cables, reducing voltage drop, or using MPPT charge controllers.

The Solar Charge Controller should be installed in the circuit between your Solar Panel and your battery. It is always recommended to have your solar charge controller as close to your battery as possible.

It is highly recommended that the charge controller be within one meter (approximately 3.25ft) of the battery bank and in the same room or enclosure. Be sure all rooms and enclosures are well ventilated.

It is recommended to have up to 2% voltage drop at the DC side while only 1% is accepted at the AC side of the system for a total of 3% in voltage drop for the entire system. Wires should be sized to reduce resistive (heating) loss to less than 3%.

Battery overcharging protection voltage is also called fully-charged cut off voltage or overvoltage cut off voltage. The voltage value should be set according to the battery type. The voltage value range is between 14.1V to 14.5V for 12V system, 28.2V to 29V for 24V system and 56.4V to 58V for 48V system.

The MPPT operating voltage range for most string inverters is between 80V and 600V, depending on the inverter make and model. The voltage range for Solar MPPT charge controllers is generally much lower and varies from 24V up to 250V. However, several high-voltage models are available which operate up to 600V.

It should ideally take around 10 to 20 hours (during the daytime) to charge a 100 Ah battery with a 200W solar panel.

How far can you run wires from solar panels? ›

The length of the wires is crucial in maintaining efficiency. For optimal energy transmission, it's recommended to keep the distance at 50 feet or less. This shorter distance ensures the voltage drop remains within an acceptable range, specifically at or below a 2% decrease.

PWM solar charge controllers hold the voltage more constant. If a PWM controller has two-stage regulation, it will first hold the voltage to a safe maximum for the battery to reach full charge. Then, it will drop the voltage lower, to sustain a “finish” or “trickle” charge.

So, if you have one 100-watt solar panel, a 10 amp charge controller would be necessary, as it is safer to round up. If we had 3 100-watt solar panels, the equation would be 300/12 = 25 amp, so we would suggest getting a 30 amp charge controller.

It is usually wise to put your solar charge controller as close to the batteries as possible to avoid voltage drop. It is less important (from a battery charging perspective) to have the solar charge controller close to the panels themselves.

Re: Solar controller mount on panel or near battery

Some controlers has a temperature sensor to gage the temperature in the vicinity of the battery for optimal charging according to estimated battery temperature. This controlers must obviously be placed as close to the battery as possable.

Should you be worried? Solar panels can overcharge a battery, but this generally doesn't happen so long as we understand them and follow manufacturer guidelines. This article gives insight into the damages caused to the batteries due to overcharging and how this can be prevented.

However, there are some potential disadvantages associated with their use: Cost: Charge controllers can add to the overall cost of a solar power system. High-quality charge controllers that offer advanced features like MPPT can be particularly expensive.

What a MPPT charge controller does is that it boosts the voltage and the current of the system, as close as the I-V curve of the module. In this case, the MPPT charge controller charges the battery at almost 18.3 V and 11.48A, while using the most out of the solar panel.

MPPT charge controllers convert the higher voltage DC output from solar panels down to the lower voltage needed to charge batteries.

The funny thing about battery voltage is that it changes depending on the charge of the battery.