BP365U with Xantrex C40 for 12volt bank

krogerssolar

Hi all new to this form but not new to solar power. I have four BP365U panels that i had been given i have them mounted to a zomeworks mount I'm planing on wiring them in series since they where previously wired that way before i got them. What I'm trying to figure out i have mainly only used outback power mppt charge controllers on my main power system this will be powering some outdoor lighting and some model train items. I have a xantrex C40 CC would this work i know its spec say it can handle up to 125vdc in but can i bring power in around 90volts open current and let it charge a 12volt battery bank or should i look at a small MPPT controller that can handle step down.

specs on the panels are attached 8)

Cariboocoot

Re: BP365U with Xantrex C40 for 12volt bank

Welcome to the forum.

To use those panels with a C40 controller you need to wire the panels all in parallel. The C40 is a PWM type controller and does not have the ability to down-convert higher Voltage into greater current.

Wiring them all in series would in essence be wasting three of the panels because the current will remain at Imp but the Voltage will be "pulled down" to battery level.

You should have fuses/breakers on each panel too. Note the "maximum series fuse" rating of 20 Amps; they should be under that. Could be as low as 5, but you will probably find 10 easier.

krogerssolar

Re: BP365U with Xantrex C40 for 12volt bank

Thanks for the the info. If i where to wire the panels two sets of panels wired in series then bring them to my combiner box to parallel them and bring them into a MPPT controller say something close to a morning star sunsaver mppt would a controller like this one work. http://www.solar-electric.com/mosumpsochco.html i would like to keep my wire size smaller hence i would like to series all four but i would end up needing a outback FM60 which would be a waste for this setup. Would you be able to give me a refresher if i made two sets of series wired panels and paralleled the two sets do the volts and amps stay the same this part I'm stumped on i haven't done this in a while.

Thanks Kevin

Cariboocoot

Re: BP365U with Xantrex C40 for 12volt bank

At 65 Watts * 4 you have only 260 Watts to work with. That will "max out" a Morningstar MPPT 15.

Now, how patient are you? Rogue has just announced their new MPT-2024 will be available this month. Specs: http://www.roguepowertech.com/documents/MPT2024Rev1-Specs.pdf

Technically it would take all four in series, although the greater difference between array Vmp and system Voltage the lower (by a small percentage) the controller's conversion efficiency.

krogerssolar

Re: BP365U with Xantrex C40 for 12volt bank

Thanks for your Replay that dose look like a good option i don't mind waiting to try that out thanks for that info.