Which Regulator

[pjwooly]

Hi all can some one please tell me ....

I have purchased a 140W solar panel to charge my 130ahr battery in the ArkPac but am unsure which solar controller I should buy regarding the amp size and if it needs to be a PWM type or a MPPT type controller.

Thanks in advance.

Pjw.

 

[Old.Tony]

MPPT has the potential to charge the battery faster than PWM. There's no guarantee there, but MPPT should have (on average) a slightly higher wattage output than PWM.

MPPT means "Maximum Power Point Tracking" which is a fancy way of saying "a system used to extract the maximum amount of power out of a solar panel".

PWM means "Pulse Width Modulation" which is like turning on and off the power to the device (battery) rapidly. This will reliably charge the battery but because it really focusses on switching on and off the output rather than gaining anything, its output in watts (voltage times amperage) should be less than that available from MPPT.

Which is the best? Either will do, really. I think the difference is going to be fairly negligible over a single (or even 10) solar panels, so the gains made by MPPT over PWM won't be worth it. If you're cutting the line so close that the difference IS important, then the natural decay inherent in an aging solar panel is going to bite much sooner.