A controller designed for larger systems
As soon as a solar array goes beyond a few hundred watts, the choice of controller determines everything else. This Wattstunde model handles a charge current of 60 A and adapts to four battery voltages: 12, 24, 36 or 48 V. Detection is automatic; for a lithium battery, the datasheet mentions only 24 V with automatic detection. Such a range lets you keep the same device when a storage bank evolves.
A few usage scenarios
A remote holiday home whose roof carries several rows of modules will find a charging stage here that can keep up. A farm, a telecom relay or a long-term off-grid work site can also use it to maintain their batteries. The experienced home user sees a way to scale up without multiplying small controllers.
Panel power by bank voltage
- 12 V: 750 W of nominal photovoltaic power
- 24 V: 1500 W
- 36 V: 2250 W
- 48 V: 3000 W
The higher the battery voltage, the larger the solar array you can connect for the same 60 A current. That logic often leads to choosing a higher voltage once a system passes a certain size, so as to reduce cable cross-sections.
Construction
The housing is 262 x 186 x 97 and weighs 2.5 kg, a substantial size. Its IP 32 protection rating calls for dry installation, in a room or a closed enclosure. The self-consumption, below 8 mA, has no real impact on the energy balance of a battery bank of this size.
Wiring and settings
The maximum open-circuit input voltage is 138 V: work out the number of modules in series with a margin, because voltage climbs as temperature falls. Follow the sequence given by the manufacturer and check that the recognised voltage matches your battery before the first charge. For cables, fuses and breakers, have a qualified professional validate the sizing, especially above the low voltages.
What to remember
High current, four supported voltages and a wide power range: these three qualities make this controller a versatile piece of equipment, designed for systems that evolve.
Technical data
- Brand: Wattstunde
- Charge current: 60 A
- Battery voltage: 12/24/36/48 V, automatic detection (lithium only 24 V, automatic detection)
- Nominal PV power: 750 W at 12 V, 1500 W at 24 V
- Output: 12V/750W – 24V/1500W – 36V/2250W – 48V/3000W
- Maximum PV open-circuit voltage: 138 V
- Self-consumption: < 8 mA
- Protection rating: IP 32
- Dimensions: 262 x 186 x 97
- Weight: 2.5 kg
Safety and maintenance
A 60 A current quickly heats a conductor that is too thin: choose short, sturdy cables, tighten the lugs and leave clear space around the unit. Always switch off the energy sources before working on it. Wipe the housing dry, inspect the connections regularly and, if the unit is removed, store it somewhere dry.
