Solar controller tie in

RLS7201 wrote:
No need to worry about distance between charge controller and batteries. You can purchase a MPPT controller with adjustable voltage or get a charge controller with separate voltage sense leads. Just make sure the wires are large enough to carry the current.
My controller is over 25 feet from my batteries and has separate voltage sense leads & is fully adjustable. Maintains the batteries correctly.

Richard

BFL13
Here’s the full quote and note that he has a MPPT controller which converts the panel power to battery power minus losses – ie watts. Any voltage drop in the wiring results in less amps delivered to the battery for a given voltage. For him it’s an acceptable tradeoff but others may want/need more battery charging so I was just making the point that voltage loss means less amps and hence power to the battery. His point is good that his controller with remote voltage sensing allows him to accept the wiring loss and provide an easier install.

PWM controllers are different is that for example a 12V panel (18V actual) charging a 14.8V flooded battery in bulk will lose the power associated with the 3.2V since charging is restricted to panel amps and not panel power (as long as the voltage is adequate) unlike MPPT controllers. I.e. The power loss associated with the 3.2V is a given for a PWM controller as its simpler design does not harvest that power.

Certainly, once absorb charging begins battery amps and voltage (power) tapers off. However, during the entire charging cycle and beyond house loads also use power which first comes from the panels and then from the battery. So again, wiring loss can becomes a factor when camping with house loads.