In short
- Low voltage: modules in parallel, about 48 V, for low-voltage hybrid inverters.
- High voltage: modules in series with a dedicated controller, for high-voltage inverters.
- The inverter model and the label of the system usually answer the question in a minute.
Several WeCo modules, the 5K3 in particular, are sold as dual-voltage: the same module can be part of a low-voltage or a high-voltage installation. The choice is made by the installer, according to the inverter. From the outside the modules may look alike; electrically, the two systems have little in common.
Low voltage: modules in parallel
In a low-voltage (LV) installation, each module sits at about 48 V nominal and the modules are connected in parallel. Adding a module adds capacity, not voltage. The cluster connects to a low-voltage hybrid inverter, and one of the modules, or a hub on larger clusters, talks to the inverter.
High voltage: modules in series
In a high-voltage (HV) installation, the modules are connected in series, so their voltages add up to a few hundred volts. A dedicated controller manages the stack and talks to the inverter, which must be a high-voltage model. Adding a module raises the voltage of the whole stack.
How to tell yours
| Clue | Low voltage | High voltage |
|---|---|---|
| Inverter battery input | 48 V or “low voltage” in the datasheet | A wide range of hundreds of volts |
| Battery voltage shown on the inverter | Around 50 to 55 V | Well above 100 V |
| Extra box on the stack | Usually none, or a hub on large clusters | A controller unit at the top or bottom |
| Power cables between modules | Thick cables to a common busbar | Modules chained one after another |
The quickest check is the battery voltage on the inverter screen. If it shows around 52 V, you have a low-voltage cluster.
Why it matters for monitoring
The communication of the two systems is organised differently. In LV, the modules share a bus that a monitor can read on a free RS485 port. In HV, the controller sits in between and speaks for the whole stack.
WeCo Monitor is built and tested for low-voltage clusters. If your system is high voltage, write to us before ordering: we tell you honestly whether it can be read, and we never ask you to open the controller or touch the high-voltage side.
A high-voltage battery is a job for a qualified installer. Never open its covers or unplug its cables yourself.
Common questions
Can I convert my cluster from low to high voltage?
That is a design decision for your installer, linked to the inverter. It is never a simple change of cables.
Are 4K4 modules dual-voltage too?
Versions differ. The label and the manual of your modules say how they can be used.
Does the box read high-voltage stacks?
This edition reads low-voltage clusters. High-voltage stacks are on our list; write to us with your configuration.
