how many amps can mc4 wires handle in parallel?

Re: how many amps can mc4 wires handle in parallel?

Technically, the DC to DC converter is "throttling" the energy throughput from the Solar Array to Battery bank.

It is just normal operation or "the nature of the beast".

Buck Mode Switch Converters are probably the easiest to understand of the switching topologies. Try reading about them here:

Buck converter

Basically there is an Inductor from the input to the output...

When the "switch" closes, the current starts flowing through the inductor (slowly increasing). At some point the switch is opened, but the inductor wants to keep the current flowing, so there is a diode that supplies current (from ground) and the current slowly slows down again (the inductor is storing and giving up energy). Then the whole cycle repeats... The more the switch is closed, the more energy/current flows form the solar array (i.e., towards 100% closed).

As the computer decides less current is needed, the switch is closed for less time during the cycle (towards 0% percent), and very little average current flows.

A buck mode down converter (MPPT type charge controller) uses PWM (pulse width modulation) to control current/energy flow through the converter.

A pure PWM charge controller---Replace the inductor with a copper wire. And toss the diode. Just an "on/off switch". Cheaper to make, but as you can see, it has now way to "regulate" instantaneous current through the switch. So if you put too large of an array (or a higher voltage battery) on the input to a "pure" PWM controller, you will get current spikes that exceed the current capability of the supply.

A good quality MPPT charge controller (designed for the job) can actually be connected directly to a higher voltage battery bank and very nicely recharge a lower voltage battery bank (i.e., a 24 volt battery bank => MPPT controller => 12 volt battery bank) and be very happy.

If you tried this with a PWM controller, it will cook the internal electronics/conductors (no current limiting/regulation possible).

MPPT charge controllers are also very good at taking high voltage/low current from the array and efficiently down converting to the low voltage/high current needed to charge the battery bank (~95% efficiency). Because the inductor is efficiently converting the energy from the panel to the bank.

It is the first switch mode regulator I learned about--And I always thought they were very neat.

-Bill