• Are all the MPPT charge controllers from the inverters individual or are they hooked up to each other?

    If you use more than one Any-Grid unit then each one will handle its own PV array and the PV modules may not be inter-connected between more than one unit. So if you are multiplying the number of devices you are also multiplying the number of MPPTs and the MPP trackers work independently of each other. This optimizes the PV harvest with partial shading or other suboptimal situations.

  • Are the Any-Grid’s fans loud? When do the fans run?

    The Any-Grid fans are always running. However, they are running at a reduced speed when the inverter is pushing low power.  When the inverter is converting low power, the fans will run at about 30% speed and will ramp up in accordance with the output power or the PV input power—it will take the higher of the two and immediately change the fan speed depending on the power—so they always run but they are speed-controlled. The fans are definitely loud in the sense that you will probably not want to mount this in your living room. This is something for the basement or a separate room. Also, because typically in most countries it is not even legal to be in the same room as the batteries, especially for lead acid batteries where you will have hydrogen coming out of the batteries which needs some ventilation, etc. So we would definitely not recommend having this in your sleeping quarters or your living room. The fans will always be under 60 dBa. When running at 30% fan speed the noise is roughly 35 dBa.

  • Are there any requirements if you install thin film Modules?

    Not from Phocos, but maybe from the thin film module manufacturer. The Any-Grid PSW-H allows you to have any grounding configuration you would like on the battery but you are not permitted to ground the positive or negative terminal of the PV side. If your thin film PV module manufacturer requires you to ground the positive or negative DC terminals then the Any-Grid PSW-H would not be the right product for that.

  • Can the Any-Grid be AC coupled?

    I believe what you mean by AC coupling is connecting a grid injection inverter on the AC output—that you cannot do. The AC output is unidirectional, it’s only for providing power to loads. It cannot accept power from a grid-connected inverter. If you wish to increase the PV capacity then either add another Any-Grid PSW-H in parallel (you may disable the AC load output and use it purely as an MPPT charge controller on the same battery) or use a separate MPPT DC charge controller in parallel to the Any-Grid on the same battery.

  • Can we use different types of lithium batteries other than Pylontech?

    Yes, for now only Pylontech is supported in terms of a BMS (battery management system) communication link with the battery. We have very many different battery settings and as long as your battery has 48 ~ 50 Vdc nominal voltage, you can modify the settings of the Any-Grid to cater toward those batteries. For batteries where we do not support BMS communication, make sure the batteries will function even without such communication and will not simply shut down after some time.

  • Can you offer more detail about how the Phocos PSW-H Hybrid Inverter works in split-phase environments?

    Please read our blog post "Any-Grid Hybrid Inverter in Split-Phase Environments" for more information.

  • Can you use an auto transformer/neutral transformer like others do to get 120 Vac?

    Yes, you can. Be sure that on the AC input side you are always connected to one neutral and one live wire though, never just two live wires of two phases on a single unit.

  • Do the 120 Vac devices have the same programmability features as the 230 Vac models?

    Yes, they do and you are able to change the nominal AC output voltage to 110, 120 or 130. 

  • Does the Any-Grid have a physical internal transfer relay?

    Yes, there are three. One between the loads and the inverter; one between the grid or AC input neutral and the AC output neutral; One between the AC input phase and the AC output phase. When the Any-Grid disconnects from the grid it disconnects both neutral and live wires from the AC input.

  • Does the Any-Grid have a Wi-Fi or 4G network connection?

    No, there is only BLE available right now. However, we are currently working on remote monitoring with Wi-Fi / Ethernet.

  • How are firmware updates handled?

    The device has a USB OTG port. So, if there is a firmware update required, then we can release it and you can simply plug in a USB OTG (microUSB) dongle and the inverter can update itself from there.

  • How can we connect the Any-Grid PSW-H inverter to the PhocosLink App?

    This is a BLE app so the display unit of the Any-Grid has an integrated BLE chip and you can simply connect to that like you would to any other BLE device. You enter your passcode and then as soon as you’re within range of the Any-Grid you can just open up your PhocosLink app and you will see everything that’s happening on the Any-Grid unit.

  • In a 3-phase system, is it ok to connect PV to only one of the inverters?

    Yes, it is. All three of them will work individually regarding the PV side.

  • In central America, we have phase 1, phase 2 and neutral with 120 Vac on each line with 60 Hz. Does this work with the Any-Grid PSW-H?

    It does not work with the 230 Vac models. However, with the 120 Vac models developed for the Americas, this is possible. If you want to use both 230/240 Vac and 120 Vac loads, you will need to have at least 2 inverters. You will connect one inverter between neutral and phase 1 and the other inverter between neutral and phase 2 (split-phase). If you want to use just one inverter you can only work with a 120 Vac inverter and it will be up to you if you connect it to neutral and phase 1 or neutral and phase 2, but you cannot ever connect any Any-Grid between phase 1 and phase 2. One of the two conductors must be neutral.

  • Is 3-phase AC available in the US for the Any-Grid?

    The Any-Grid PSW-H is a single-phase device and you can interconnect several of them to have either single-phase (parallel), 3-phase or split-phase (only 120 Vac models) systems. For 120 Vac per phase and for split-phase systems, be sure to choose the 120 Vac version of the PSW-H. Split-phase/2-phase with 180° phase shift requires at least 2 devices and 3-phase requires 3 devices. Single-phase only requires at least one device.

  • Is Anti-Islanding protection available?

    Technically possible, but it is currently not implemented. As grid certification is conducted this feature will be implemented for various grid certifications. Of course anti-islanding only makes sense while the inverter is in On-Grid mode (parallel to the grid). Regardless of this function, if the grid voltage falls outside the limits (170 ~ 280 Vac and 40 ~ 65 Hz in UPS mode for 230 Vac models, half that for 120 Vac models), the PSW-H automatically switches to Off-Grid mode. When it disconnects from the grid it is galvanically isolated from the grid. There is no connection between neutral or a line and the grid and that.

  • Is it possible to continue feeding the AC consumers with the battery (without injecting) when the grid has failed?

    Yes, if the grid fails and the AC input voltage drops below 170 V (in UPS mode) or the frequency drops out of the window of 40-65 Hz the Any-Grid will declare the AC source invalid and will disconnect it completely by mechanical relays. The Any-Grid will then automatically act as an Off-Grid inverter within 10 milliseconds and provide power to your loads without any risk of back-feeding into the grid because it is then galvanically isolated from the grid on both neutral and line wires.

  • Is there a board replacement program?

    If there are problems with the device we discuss that with the customer. In some cases it is economically viable to send it to Phocos or a Phocos service partner and in some cases it is not. It depends on the system, the type of issue, the urgency, etc. If a board replacement is to be done, that will void the warranty if done by a non-authorized customer because we cannot assume the risk for people installing boards.

  • Is there a way to limit the AC output load at night with no utility power to conserve battery power apart from turning off appliances manually?

    No because there is only one load output so there is no solution for that. But you could use an AC power relay whose coil is controlled by the grid voltage. Like this if the grid fails, the relay opens and this would allow controlling a second AC circuit for non-critical loads.

  • What are the typical competitors the Any-Grid targets?

    From the functionality standpoint: purely Off-Grid inverters, uninterruptible power-supplies (optionally with PV connection), On-Grid inverters, as well as grid-connected storage inverters. The Any-Grid PSW-H combines all those functions in one package.

  • What happens if one phase goes down?

    If you’re working with a 3-phase system and at least 3 Any-Grid systems, as soon as one of the phases goes out of speck, all three Any-Grids will automatically switch to Off-Grid mode.

  • What is the warranty for the Any-Grid?

    The warranty period is 2 years. 

  • Why are we not able to connect a single Any-Grid to 2 phases?

    For a residual current device to work we internally connect neutral to ground when we’re in Off-Grid / battery mode. If we were to do that with one of the two phases, which is what would happen if you connect 2 phases onto the inverter instead of one neutral and one phase, that would not work and it would probably damage the device.

  • Are AGM, flooded or gel batteries my only energy storage options compatible with a Phocos charge controller?

    Most Phocos controllers are designed specifically for lead acid batteries such as AGM, flooded, or gel batteries. Sometimes programmable Phocos controllers can be made compatible with other chemistries such as lithium ion. If you would like to use a battery chemistry other than lead acid, please contact Phocos technical support with a datasheet for the battery you want to use.

    CXNup controllers come with a built-in profile for lithium iron phosphate (LiFePO4) batteries.

  • Are Phocos charge controllers protected against lightning?

    Phocos charge controllers are CE compliant which includes rigorous surge protection. Phocos charge controllers have internal surge protection which will guard the PV output and battery input, but not from a direct lightning strike. The controller may withstand indirect strikes that occur nearby.

  • Can I use my CIS series controller with a motion sensor?

    Yes. Find out how in this Tech Bulletin

  • Does Phocos have instructions for CXup and CXNup load settings?
  • How do I adjust the settings on my charge controller, such as the low voltage disconnect (LVD) threshold or dusk to dawn hours?

    Use the CIS-CU remote control or MXI-IR interface with CISCOM software for charge controllers of the CIS family.  For the CXNup family, use the MXI interface with PhocosLink software or the integrated LCD and programming buttons. The settings of the MPM system can be changed via MCU with MXI interface and MODCOM software and via DIP switches. With other Phocos charge controllers, such as the ECO series, the settings cannot be changed. 

    Check the datasheet or user manual for more information, or contact Phocos technical support.

  • Is there any other equipment or hardware that I need to purchase for safety of the PV system?

    For safety purposes, it is highly recommended that the user places a fast acting fuse or DC breaker between the ungrounded lead of the charge controller to the corresponding battery terminal as close as possible to the battery terminal. This will protect the conductor, device, and user from overcurrent. It is recommended installers use electrically insulated tools when wiring a system and follow applicable laws for the installation region.

  • What are the differences between ‘middle of night’ and ‘dusk to dawn’ settings in CIS-N, CIS-MPPT and CXN controllers?

    The difference is reference points for load or dimming timers to give you more options save energy and improve user experience.

    CIS family and CX family controllers intelligently detect day and night using the PV array voltage. Night is detected when PV voltage drops below a low level during dusk, and day is detected when PV voltage rises above that low level during dawn. For example, CIS family controllers in 12V systems detect night when PV voltage drops below 8V, and they detect day when PV voltage rises above 9.5V. Two slightly different levels ensures a smooth transition during cloudy weather.

    These Phocos controllers also intelligently calculate the middle of the night as halfway between night detection and day detection. This is updated each night for high accuracy throughout the seasons. There is no real-time clock so there may be variation between true midnight and what the controller measures as the middle of the night.

    When “dusk to dawn” is selected as a reference, the load timers can be set to turn the load on (or dim) for a selectable number of hours after dusk and a selectable number of hours before dawn. Alternatively, the load can be on the entire night.

    When “middle of the night” is selected as a reference, the load timers can be set to turn the load off (or dim) for a selectable number of hours before the middle of the night and a selectable number of hours after the middle of the night.

    For example, in a CIS controller, if evening hours are set as “3” and morning hours as “2” with a “middle of the night” reference, the controller will turn the load off three hours before the middle of the night and back on two hours after the middle of the night. (see screenshot of CISCOM setting below).

    Even if the hours selected exceed the length of night, the controller will still shut off the load at dawn and turn on the load at dusk.

  • What are the key differences between PWM and MPPT charge controllers and which is best for my application?

    PWM (pulse width modulation) charge controllers are simpler charge controllers compared to MPPT controllers. A PWM controller uses very fast switching, many times per second, to control the current flow from a PV panel to a battery for charging. PWM controllers work best when the nominal voltage of a solar array matches the nominal voltage of a battery bank.

    MPPT (maximum power point tracking) controllers use conversion technology for charging. An MPPT controller does not require the solar panels to be of the same nominal voltage as the battery bank. It can convert PV power at a high voltage to charge power at a lower voltage for a battery bank. MPPT controllers can be up to 30% more efficient than PWM, but they are often more expensive and unnecessary for small systems.

    Read our document “Comparing PWM & MPPT Charge Controllers” to learn more.

  • What do the load terminals on my charge controller power?

    The load terminals on a charge controller power connected DC devices. The DC device must be compatible with the battery nominal voltage, and the battery bank capacity should be appropriately sized for the load. Loads can be many things from a DC refrigerator to a DC LED light.

    Some loads should not be connected to the controller’s load terminals and instead connected directly to the battery. Highly inductive loads with high inrush currents may damage the controller’s load terminals. DC motors and inverters are examples.

  • What is a nominal voltage?


  • What is low voltage disconnect (LVD)?

    The LVD feature on a charge controller turns off the load of a system automatically when the load drains the battery bank to a low voltage. LVD protects your batteries from reaching a depth of discharge that may damage them and reduce their lifespan.

    Phocos has developed three types of LVD to protect your batteries. One type is voltage controlled LVD. When the load drains the battery to a specific voltage, the controller switches off the load within a few minutes. Another type is SOC controlled LVD. The controller considers the battery state of charge and load current to dynamically determine when to switch off the load. The controller typically takes about half an hour to switch off the load. A third type is emergency LVD, or undervoltage protection. This is a very fast acting LVD usually triggered due to errors or fault conditions when the battery voltage suddenly drops to an extremely low level.

  • How do I correctly size my charge controller for wintertime low temperature effects on PV panels?

    Cold winter temperatures can damage controllers due to low temperature effects on PV panels. Damage occurs when the cold weather panel voltage increases above the Standard Test Condition (STC) ratings.

    Below is a quick, five-step worksheet to size your controller appropriately for low PV cell temperatures. You’ll need to have the manufacturer’s product specifications for the PV panels and the charge controller to complete the worksheet.

    In Step #3, NEC Article 690 Table 690.7(A) Voltage Correction Factors for Crystalline and Multicrystalline Silicon Module is the source for the factor of 1.25 used to calculate a worst case panel voltage condition in -40°C weather.

    There are other methods and NEC factors that might be applicable, but this is the quickest, easiest check. If you do not know about worst case ambient temperatures at the install location, then use the worst case 1.25 factor or consult the NEC.

    5-Step Worksheet for Sizing Charge Controllers for Minimum PV Panel Temperatures
    Step #1 Panel Voc
    Enter panel Voc at STC from your panel datasheet or nameplate here:

    Step #2 Series String
    Enter number of the above panels wired in series here:

    Step #3 Array Voc @ STC
    Multiply #2 by #1:

    Step #4 Array Voc with Min. Cell Temperature
    Multiply #3 by 1.25:

    Step #5 Controller Check
    Is #4 ≥ maximum controller solar input voltage specified on the datasheet of your selected controller?

    If #4 is greater or equal to maximum controller solar input voltage, the selected controller is not suitable for the system as designed. Select a controller with a max solar input voltage ≤ #4 and/or change system wiring configuration and start over.
    If #4 is less than maximum controller solar input voltage on the datasheet of your selected controller, it is suitable for the system as designed.

  • What are tips for sizing a MPPT charge controller to my PV panels?

    Here are 2 important reminders for sizing MPPT controllers:

    Tip #1 PV panel Vmp > controller’s minimum solar input voltage.
    The panel voltage at maximum power (Vmp) should be higher than the controller’s minimum solar input voltage specification. For 12V systems, this is typically 17V. For 24V systems, this is typically 34V.

    Tip #2 Don’t pair one 60 cell panel to a 24V battery bank.
    Using one 60 cell panel to charge a 24V battery bank is not recommended. The Vmp is typically too low to charge the batteries sufficiently.

  • What are tips for sizing a PWM charge controller to my PV panels?

    Here are 3 important reminders for sizing PWM controllers:
    Tip #1 PV panel Vmp > controller’s overvoltage protection level for the battery.
    The panel voltage at maximum power (Vmp) should be higher than the controller’s overvoltage protection level for the battery. The battery overvoltage protection level is typically 15.5V for 12V systems and 31V for 24V systems.

    Tip #2 Pair 12V battery banks with 36 cell panels.
    12V battery banks perform best when paired with 36 cell panels. When larger panels such as 60 cell panels are used, the power output will be far less (<50%) than the maximum rating even in full sunlight. This is not recommended.

    Tip #3 Pair 24V battery banks with 72 cell panels.
    24V battery banks perform best when paired with 72 cell panels or strings of two 36 cell panels in series. When a smaller panel array is used, such as one 60 cell panel, the voltage is typically too low to keep the batteries charged properly, resulting in reduced battery life. When a larger panel array is used, such as two 60 cell panels in series, the power output will be far less than the maximum array rating even in full sunlight. This is not recommended.

  • Can I program multiple dimming levels with CISCOM?

    CISCOM only allows for single level dimming. So, you can dim your light to, say, 50%, but you cannot dim it to another level after – it can only operate at 100% or an arbitrary dimming value.

  • CISCOM values are programmed for 12V systems; how do I program for 24 or 48V?

    To interpret CISCOM settings for a 24V system, multiply the given 12V values by a factor of 2. To interpret for a 48V system, multiply the given 12 V values by a factor of 4. 

  • How are dimming settings controlled?

    Dimming is controlled through battery SOC or through dawn to dusk/middle of night settings. These settings are compatible with one another, so you can dim your load with SOC/battery voltage and with dawn to dusk/middle of night mode. This dimming combination can make your lighting system even more energy efficient.

  • How do I know if my CISCOM or CIS-CU settings were successfully transmitted to the controller?

    The CIS controller family has a LED display that will show if it is communicating with the CIS-CU or MXI-IR. Two red LEDs will light up in pairs with short interruptions, and CISCOM will notify you if the controller successfully saved the settings or not.

  • How do I use CISCOM with my CIS charge controller?

    You can use CISCOM with a MXI-IR USB cable or with a CIS-CU. You need one of these units to send information. These components are  available through Phocos distributors. See our website for a list of distributors near you, or contact our Sales Department. 

  • My MXI-IR cable is not reading or sending the settings from the controller. What should I do?

    Ensure that the drivers for the MXI-IR are installed properly on your computer. If you have done this and still need help, please contact our Technical Department for assistance.

  • What do each of the values correspond to under the “load disconnect settings due to low battery SOC” indicate?

    This section controls load behavior, such as low voltage disconnects and dimming percentage. A low voltage disconnect is imperative to not permanently damage your batteries. “LVD load 1 offset” controls LVD relative to voltage or SOC.
    If you do not have a CIS-N-2L, you only can operate one load per controller. Load 1 refers to a load that is not being dimmed. “LVD Load 2” is for a load that is going to be dimmed. If you do have a CIS-N-2L, load 1 cannot be dimmed, but load 2 can. This does not imply that load 2 has to be dimmed. If you have a CIS-N-2L, go back to the main menu and select “CIS/CIS-N Dual Load Controller” instead.
    “LVD: Base + Offset (V)” changes LVD relative to voltage, from a base level of 10.98V. When you select “voltage” under LVD indicator type, the offset can be adjusted to 10.98V to 17.35V. Base is the value you cannot go under and offset adjusts the voltage relative to the base. Note: This setting is only possible when "EXPERT-MODE ENABLED" is selected in the "Battery Charge Regime Settings" menu. 
    Emergency high/low-voltage values dictate when the controller will turn off based upon extreme battery voltage levels.

  • What values correspond to the individual values in the section “Battery charge regime settings” (only available if the “EXPERT MODE ENABLED” is activated)? What does the terminology mean exactly?

    Custom settings are disabled in this section "EXPERT MODE DISABLED" as our engineers have determined that these default settings are best suited to extend the life of lead-acid batteries. Depending on the type of battery selected, these values will change for different lead acid chemistries (liquid or sealed). 

    Equalize voltage is specific to flooded batteries. Flooded batteries require a regular equalization charge to remove sulfation that accumulates on the internal plates of the battery, which is a natural consequence of repetitive battery cycling. Non-liquid, lead acid batteries do not require equalization, but do require a regular boost charging voltage.

    Boost is a target charging voltage for a lead acid battery, which your charge controller will regulate to when there is initial input power or when a battery has reached a low SOC. This will happen at the beginning of each day (when the panels first receive sun) and when the controller first turns (when it is initially connected or reconnected to a battery). 

    Float is a target voltage that occurs once the battery has reached sufficient SOC. 

    The temperature compensation value is used in conjunction with your charge controller’s temperature sensor wire. Battery voltages will change when environmental conditions are hot or cold. The battery voltage decreases with higher temperature because temperature has a large effect on resistance. To compensate for fluctuating environmental temperatures, a value of 24 millivolts/Kelvin is used. This is a generalized temperature compensation value, but if you are living in extreme weather conditions, contact our Technical Department for more appropriate recommendations that best suit your environment.

  • What’s the default load programming setting?

    The night light function is inactive and the light/load behavior for CISCOM is set to a charge level (SOC) of 4, whereby the load/light goes out at SOC level 4. This is typically between 11.9 V (small load) and 11.4 V (maximum load) for a 12V battery. 

  • Will my CISCOM or CIS-CU settings be erased if the controller turns off, then is reconnected?

    CISCOM or CIS-CU settings that are successfully transmitted to your controller will not be erased if the controller is disconnected from power. The internal microcontroller has non-volatile memory and does not require a constant source of power to retain information stored on it. 

  • I can see my device but cannot connect to it?

    The phone will be prompted to pair with the device during the first time a connection is attempted. Ensure ‘Pair’ is selected and the default pairing pin is “123456”. Depending on the Android version, the ‘Pairing’ request will be displayed in a pop-up screen or in the notifications bar.

  • If my phone runs on Android 6.0 or earlier, why is my app not working properly?

    The PhocosLink App is only designed and tested on Android versions 7.0 or later. Prior Android versions may work but are not supported. Android Manufacturer Models used must also support Bluetooth Low Energy (also known as Bluetooth Smart).

  • What if my question wasn’t answered here?

    For further PhocosLink App support, please email software@phocos.com

  • What is the app not showing my history data?

    The PhocosLink Mobile app is not able to retrieve historical values of the connected Any-Grid PSW-H device at this time. It is designed for real-time data only as of now. Phocos is working on online remote monitoring solutions to allow comprehensive analysis of historical data from anywhere in the world, to complement this app.

  • Why does my device disappear from “My Devices” list after the app is forced closed?

    Ensure the installed version of the PhocosLink app is “1.0.8” or later so that the devices are stored locally on the app. You may enable auto-updates from the phone settings to ensure having the more recent updates automatically.

  • Why is my device never found under ‘New Devices’?

    a. Ensure Bluetooth is enabled on your phone.
    b. Ensure you are within range (7 meters / 23 ft) of the product.
    c. Press the green refresh button on the bottom-right corner to make sure a scan is initiated.
    d. On Android, permission for Access to Location services is needed and must be granted for Bluetooth to work. This access permission is only asked once either through a pop-up or in the notifications depending on the Android device/version. On some devices, when this access permission is given outside of the app (Phone Settings -> Applications -> PhocosLink -> Permissions), the phone must be restarted after enabling Location Permission for the changes to take effect.
    e. Make sure the ‘Location’ in the Android Settings is enabled/ON. Otherwise, the access to Location services given to the app as mentioned previously would not take effect.

  • Why is the Access to Location services required on Android?

    Scanning for Bluetooth devices requires the access to Location Services permission to be enabled. This is because a Bluetooth scan can be used to gather information about the location of the device through a signal strength for example. The PhocosLink App does not use, save, nor transmit any Location readings. This is not driven by Phocos but is an Android requirement for Bluetooth.

    More official information about this can be found here: https://developer.android.com/guide/topics/connectivity/bluetooth

  • Can I use a 60 cell module (commonly used for grid-tied applications) with my battery bank?

    High voltage panels, or 60 cell modules, can be used with MPPT controllers. Be sure to check that your panel is within the other specifications of the controller you are using. These specs include max power input, max voltage input, and max current input.

  • How do I know that I’m receiving enough sunlight on my PV module to adequately charge my batteries?

    Check the battery voltage. If the voltage is at a target charging voltage, then the module is adequately charging your batteries. For example, if you measure 13.7V on a 12V battery, then it has reached the Float charging voltage, and the battery is being adequately charged. Remember that the target voltages may be higher in cold weather and lower in hot weather due to temperature compensation.

    Check the battery voltage over several minutes. If the voltage is increasing, the battery is being charged. If the voltage is increasing very slowly, then the module may not be receiving enough sunlight or another problem might be to blame. Check the terminal connections and any wiring connections of the PV module to the charge controller and the charge controller to the battery bank. Clean your panels and remove any obstacles causing shading, no matter how small.

    Use a controller accessory with current measurement (if applicable) or a digital multimeter to measure the module current. Compare the measured value to the module datasheet. Check the battery manufacturer datasheet or user guides for recommended charge current or charge rates (C-rates).

  • What is the optimal distance for wiring between my charge controller and my battery? 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. Lead acid batteries produce flammable hydrogen gas.

    Significant voltage drops occur not only with excessive distance but with improper wire size. Check the back page of the Phocos catalog to view a quick guide for wire sizing.

    Measure the voltage at the controller, and measure the voltage at the battery terminals. If there is a 0.5V difference or more, reduce the wiring distance or decrease the wire gauge.

  • Why am I getting less power than expected from my PV system?

    This can be due to several factors. First, your battery bank may not need it. If your battery bank is full or nearly full, the controller must limit PV power to prevent overcharging.

    Second, standard test conditions (STC) don’t always match actual environmental conditions at the install site. Thermal effects, atmospheric conditions, tilt, azimuth, and irradiance change PV performance. Check if your module manufacturer lists “NOCT” data on the datasheet. For many installations, NOCT data is closer to actual performance than STC data.

    Also, your PV array and controller may be mismatched. If you have a PWM controller, the nominal voltage of your panel should match the nominal voltage of your battery bank. If it’s higher, the PWM controller is essentially “throwing away” the extra voltage it cannot use. For example, if you have a 12V battery bank, choose a 36 cell module. The Vmp will typically be 17 to 18V.

    Other causes of power losses include loose wiring connections, module mismatch, dirty module, and orientation of the module to the sun.

Get In Touch Not sure what you need? Talk to the experts!


Phocos Americas, Inc.
Tucson, AZ USA
Phone +1 520 777-7906

Phocos AG
Ulm Germany
Phone +49 731 9380688-0

Phocos India Solar Pvt Ltd.
Puducherry - India
Phone +91 413 2972328

Phocos China Ltd.
Qingdao China
Phone +86 532 83837020

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