For sale we have the REUK Dump Load Controller.
This device is designed to power loads such as heating and lighting when a solar charged battery is well charged so that the battery does not over charge, and any surplus solar generation can be put to good use instead of being wasted.
The output from this device is rated to 2 Amps. This can be used to directly power loads totalling up to a total of up to 2 Amps, or can be used to energise a relay which in turn can switch much higher current levels.
When the battery voltage is measured to be in excess of a user set threshold (can be set to 12.1V or higher) continuously for 10 seconds, the dump load output will turn on. Then, when the battery voltage falls and is measured to be below a second (lower) user set threshold (can be set to 13.4V or lower) continuously for 10 seconds, the dump load output will turn off.
The size of this board is just 50 x 50 x 20mm.