How to Size a Victron Solar Charge Controller for a Surveillance Trailer
Meta Description: Learn how to select the right Victron MPPT controller for a mobile surveillance trailer.
A reliable solar surveillance trailer needs more than enough solar panels. The charge controller must also match the battery system, panel voltage and daily equipment load.
At BIGLUX, we select the Victron MPPT controller as part of the complete system, including cameras, batteries, solar panels, router and NVR.
What Does a Victron MPPT Controller Do?
The controller is installed between the solar panels and battery bank. It manages charging, protects the battery and improves solar energy collection.
For example, in MPPT 100/50:
- 100 is the maximum PV input voltage.
- 50 is the maximum battery charging current.
Both limits must be checked.
1. Calculate Daily Power Consumption
Calculate the total load of the trailer, including cameras, NVR, router, switch, speakers, cooling and lighting.
Daily energy use (Wh) = Equipment power (W) × Operating hours
If the system uses 100W continuously:
100W × 24 hours = 2,400Wh per day
Extra capacity should be added for system losses, poor weather and future equipment.
2. Confirm the Battery Voltage
Surveillance trailers normally use 12V, 24V or 48V systems.
The controller must support the selected battery voltage.
3. Estimate Controller Current
A simple preliminary calculation is:
Controller current = Solar panel power ÷ Battery voltage
Example:
Solar array: 900W
Battery system: 24V
900W ÷ 24V = 37.5A
A 30A controller would be too small. A 50A controller may be more suitable.
Panel voltage and current must still be confirmed.
4. Check Solar Panel Voltage
Check the open-circuit voltage, or Voc, of each panel.
When panels are connected in series, their voltage is added together. Three panels with a Voc of 40V each can reach about 120V, exceeding a 100V controller limit.
Cold weather can increase panel voltage further, especially in Canada, Northern Europe and other cold regions.
5. Check Current and Protection
When panels are connected in parallel, their current is added together.
The final design should confirm:
- Maximum PV voltage
- PV short-circuit current
- Battery charging current
- Panel connection method
- Cable size and voltage drop
- Fuse and breaker ratings
- Battery charging settings
Selecting a controller only by solar wattage may cause energy loss or system shutdown.
How BIGLUX Selects the System
Before confirming the configuration, BIGLUX checks:
- Equipment consumption
- Required backup time
- Project location and sunlight
- Lowest operating temperature
- Battery and solar capacity
- AC charger or generator needs
- Future equipment upgrades
Q&A
Can I use a larger controller?
Yes. A slightly larger controller can provide room for future upgrades, but an excessively large model may add unnecessary cost.
Can one trailer use multiple MPPT controllers?
Yes. Multiple controllers may be used for larger systems or separate solar arrays.
Which battery voltage is best?
It depends on the load. Smaller systems may use 12V, while medium and high-power trailers are usually better suited to 24V or 48V.
Can BIGLUX calculate the system?
Yes. Send us the camera models, power consumption, project location and required backup time. We can recommend a suitable solar panel, battery and Victron controller configuration.