Photovoltaic solar systems with batteries are becoming more frequent due to continuous declining prices for photovoltaic modules and other components (inverters, charge controllers, batteries, …)

Thanks to this cost reduction, pv solar energy is being used for more and more applications, some of them just unthinkable a few years ago, such as the electrification of family houses, solar pumping, small businesses, farms without electricity or with battery backup for moments where public grid is not available.

As time passes more applications like these will be profitable. In all these installations there are situations in which the energy produced by the solar panels cannot be used because there is no need at that time for consuming, not being also possible to store it in large batteries since they have a limited capacity and a price still rather high for storing all that excess of energy generated, especially in summer, spring and autumn.

The best solution, is to use this energy as heat, through electrical resistance, and later use it as domestic hot water, underfloor heating, air heating, etc. Although it is also possible with other uses, such as water extraction pump in wells, sewage pools, and more and more applications emerging as the technology is getting cheaper and mature.



Carlotrón is a device for use in photovoltaic and wind installations with batteries, with or without grid backup.

Its main function is to regulate / modulate power in water heaters, stoves, air heaters, and other heating devices with electrical resistance, depending on solar power surplus, not being required to perform any change in the resistance of the device.


Its Main purpose is to take advantage of the maximum as possible of renewable energy, respecting always the health and priority of charge of the batteries, from the starting phase (bulk), to the last phase (absortion / equalization.)

Carlotron is compatible with any other device / appliance connected to the same installation, it does not produce voltage changes that may affect them since control power is diversed to resistor progressively.
The kind of batteries used in the installation doesn´t matter, as long as the charge controller or inverter-charger are correctly configured and compatible with it.
For an exact and fast displaying, it has a 3,2” display, in which values and graphics are displayed for representing the realtime functioning.

Panel de Control Carlotrón Carlotron comes with a graphic recording which contains the energy in kwh diversed in the last 10 days hourly, though as a non graphic mode it´s posible to see the logging of total amount for last month, year, and since first use.

Each unit can control up to 2 or 3 heaters depending on the version. The order of heating of each one, can be programmed by the user.

Auto start and stop can be trigered by programming the timer, by this way standby energy is saved in the night.

In situations that heaters are need after several days without energy surplus, it is possible to activate them without waiting for energy excess by the forced diversion option, in which batteries and / or existing solar capacity will be used to provide necessary energy.


Sizes (alto x ancho x profundidad) 55/44 cm (3 chanels/2 chanels) x 13 cm x 11 cm
Weight 5 kg.
Temperature range -10ºC a 40ºC
Internal consumption 5W in standby.
Derivando potencia, variable según potencia derivada
Material Holed aluminium for a proper internal cooling.
Suported systems
  • Installations with charge regulator and output for energy surplus diversion (mandatory), Outback, Midnite, etc + inverter CC-AC
  • Installations with grid tie inverter+inverter charger, with frecuency control for reducing surplus power (SMA, VICTRON, etc).
Sistemas soportados
  • Instalaciones con regulador de carga que dispongan de salida auxiliar de derivación de excedentes (imprescindible), como Outback, Midnite, etc + inversor CC-CA
  • Instalaciones con inversor de red+inversor cargador, con limitación de potencia excedente por aumento de frecuencia (SMA, VICTRON, etc).
Battery voltaje Does not care, it´s determined by the charge regulator or inverter charger.
Batery type Does not care, it´s determined by the charge regulator or inverter charger.
Max. cable size for battery 80 mm2
Thresold of charge current 0,1 A.
AC Voltage 220-240 VAC.
Max power per cannel 2000 W máx por canal.
Conditions for use/th>

En interiores, no expuesto al sol ni al agua.

Timer Start and stop configured by solar calendar
Energy logging Last 10 days with hour thresold.
Last months/years, with daily thrsold.

Designed and manufactured in Spain.

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