Peter A Forbes
Free Member
I've posted this elsewhere, it is something that needs to be thought about by those who take their 12V loads straight from the battery with no low voltage cutoff or disconnect.
The solar controller electronics are fed from the battery the controller is connected to, not the panels. This means that if the situation arises where a continuous load pulls a battery down too far, the controller will cease working.
If the load continues, the controller cannot start and the battery will be destroyed.
It doesn't take much either, a three hundred milliamps over a week is 50AH, half what most folks have in the way of a battery, two weeks and you're looking at a severely flat battery.
Loads that are connected to the battery through the controller LOAD terminals will be cut off by the controller's own internal circuitry, protecting the battery and keeping the solar controller alive.
A single signal LED takes about 20mA, a small fan about 100mA and so on.
A relay can be connected across the LOAD terminals to carry higher loads if needed. Very heavy loads like inverters are usually only run for short periods on load, but some have a quiescent load (standby load) when turned on but not loaded, that can be half an amp or so.
Peter
The solar controller electronics are fed from the battery the controller is connected to, not the panels. This means that if the situation arises where a continuous load pulls a battery down too far, the controller will cease working.
If the load continues, the controller cannot start and the battery will be destroyed.
It doesn't take much either, a three hundred milliamps over a week is 50AH, half what most folks have in the way of a battery, two weeks and you're looking at a severely flat battery.
Loads that are connected to the battery through the controller LOAD terminals will be cut off by the controller's own internal circuitry, protecting the battery and keeping the solar controller alive.
A single signal LED takes about 20mA, a small fan about 100mA and so on.
A relay can be connected across the LOAD terminals to carry higher loads if needed. Very heavy loads like inverters are usually only run for short periods on load, but some have a quiescent load (standby load) when turned on but not loaded, that can be half an amp or so.
Peter