When the panels are far from the battery
Picture a ground-mounted array at the bottom of a garden, or a roof far from the utility room: cables run long, and the high voltage of module strings helps limit losses. The Victron Energy SmartSolar MPPT 150/35 is designed for this kind of layout. Its input tolerates 150 V, its charge current reaches 35 A and it recognises a 12, 24 or 48 V battery by itself. Built-in Bluetooth gives access to the device from a compatible mobile terminal.
Who it concerns
The home owner enlarging a solar setup for a second residence, the craftsperson installing a standalone system on a work site, the keeper of a small refuge or an isolated guesthouse: all can find a charging stage suited to relatively long strings of modules.
Working out the number of panels
Add up the open-circuit voltages of the modules in a string; the sum, increased to allow for cold, must stay below 150 V. As for power, the datasheet gives 500 W of nominal photovoltaic power at 12 V and 1000 W at 24 V. For 48 V, refer to the manufacturer’s documentation.
Material and size
The housing is made of plastic, measures 130 x 186 x 70 mm and weighs 1250 g. The electronics are protected to IP43 and the connections to IP22, which means it must be installed under cover. Its self-consumption is 10 mA.
Installation steps
- Position the unit vertically, on a sound surface.
- Provide cables of suitable cross-section between the panels and the controller, then between the controller and the battery.
- Connect the battery first, then the panel string, following the manual.
- Open the compatible app to check that the voltage has been recognised.
Connections to a household network and the sizing of protections should be left to a qualified installer.
What counts
- 150 V input for longer panel strings.
- 35 A charge current.
- Three battery voltages recognised automatically.
- Weight of 1250 g.
Specification sheet
- Brand: Victron Energy
- Model: SmartSolar MPPT 150/35
- Charge current: 35 A
- Battery voltage: 12/24/48 V, automatic selection
- Nominal PV power: 500 W (12 V), 1000 W (24 V)
- Input: 150 V
- Output: 12V/500W – 24V/1000W
- Self-consumption: 10 mA
- Protection: IP43 for electronic components, IP22 for connections
- Dimensions: 130 x 186 x 70 mm
- Weight: 1250 g
- Material: plastic
Safety and keeping
A high-voltage panel string is dangerous whenever there is light: disconnect with care, use connectors in good condition and never touch bare contacts. Wipe dust off dry and inspect the cables from time to time. If the unit is removed, keep it in a dry, mild place. For long cable runs between array and controller, ask an installer to check the voltage drop and the protection devices on the panel side. A clean, labelled layout of the string cables also makes later maintenance, or the addition of a further string, far easier to carry out.
