Confusion around VOC for MPPT

LuluBelle

Hi there. I recently purchased a new MPPT for my camper and am purchasing new panels to go with it but it stipulates that the maximum VOC must be 32Volts. I am struggling to find anything "stronger" than 160W that doesn't run higher than 32Volts VOC. Is there a way to get around this, besides purchasing a new MPPT 

mcgivor

Welcome aboard 

That's a very low voltage for an MPPT controller, I would suspect it's not an MPPT at all, there are many online which claim to be MPPT but are in fact PWM, please share an image or link to what it is you have.

LuluBelle

Thanks so much.

This is the item that I procured. 

https://www.redarc.com.au/dual-input-25a-in-vehicle-dc-battery-charger

I believe that it has a built-in MPPT. 

mike95490

You bought a battery - battery charger, not a solar charge controller

You need to return it, as it cannot work for your described use.

Then come back here, and let us know what your loads are and how much space you have for PV panels.

mike_s

It says it does MPPT, but also says it's designed to work with "12V" solar panels, which would typically have a VOC of 20-25V. If you can't find a single panel with the watts you want, you can parallel multiple panels. If you parallel more than 2, you need to fuse the individual panels.

DZL

@LuluBelle There is not a way to "get around" the Maximum Voc without buying a second controller. But you can work within that constraint. 32V means you are limited to "12v" panels (which have a Voc in the low 20's). But you can wire multiple panels in parallel up to the current (amps) or power (watts) limit of the controller. You can find specifics in the documentation.

While it may be hard to find <32 Voc panels above 160W or so, combining multiple panels in parallel would for the most part be functionally the same as fewer larger panels.

@M@mike95490 the description states clearly that this product is a combination MPPT controller and DC-DC (B2B) charger.

REDARC said:

The REDARC BCDC1225D In-vehicle Battery Charger is the next generation in REDARC's DC to DC charging technology, with additional features that make it the most advanced dual battery charger on the market.

Featuring a Maximum Power Point Tracking (MPPT) solar regulator, the BCDC1225D will charge from both solar and the alternator simultaneously. And, with built-in Green Power Priority it will select solar charging first, meaning less load on the alternator.

mike95490

Guess I was wrong and you have no worries