Solar controller tie in
I am getting ready to install a couple solar panels on my 28' Keystone Springdale and am trying to determine how to get the charging to to the front mounted 6V batteries. I was thinking of running the...
Forum Discussion
CA Traveler wrote:
"My controller is over 25 feet from my batteries and has separate voltage sense leads & is fully adjustable. Maintains the batteries correctly."
There are many installation options that produce acceptable results. However more voltage drop expecially on the battery side wiring results in less power that can be harvested from the panels.
Seems a bit muddled there IMO. Not clear anyway.
Power only matters with MPPT. And there, voltage drop only affects power output from the controller from any drop at the array side, not the battery side.
Controller output with PWM or MPPT it is all about amps to the battery to get them charged properly. It is not about power to the battery.
Voltage drop from controller to battery depends on amps flow, so as the battery is charged higher up that becomes less of a problem.
The real issue with voltage drop is that the battery will not reach the voltage set on the controller when the controller starts controlling if the amps flow is still going at that point. This might matter or not depending on what voltage the battery needs to get to.
If you have voltage drop and try to make up for it by setting the controller's voltage higher, then that will get the battery voltage higher too as amps taper. Now it matters if that voltage is too high.
As long as the battery gets to 14.4ish it doesn't matter if it gets to 14.5. (Lithiums it does matter!) There is also the time it will be at that voltage before either the charging profile drops it to a Float voltage or it gets dark.
There is some wiggle room for having longer wire from controller to battery if it will mean difficulties passing wire in the RV setting things up, and you will still have a good enough set-up, as CA Traveller said above.
