parallel tristar mppt 60 with a Xantrex C12?

lamplight

I need to add another panel to my array, i'm maxed out on my tristar (or , cold conditions will max it out). so i was going to run another panel to my C12, and have it's outputs go directly to the batteries.

will they fight with each other or no? is there a better way?

1105AH battery nak @ 12v and 875w parallelled 24v array is my current config

i planned to add one more (for now) 175w panel.

it's unfortunate that if i do it as planned i need another witre run to the batteries, but its not that far so not the end of the world, and I think I have enough spare anyhow.


thanks for any input!

mike95490

Re: parallel tristar mppt 60 with a Xantrex C12?

I think you can "over supply" the MPPT controllers, and when they hit their thermal or amp limit, they will just throttle back to a safe spot. If you think you are only going to hit that limit on cold mornings, I would go ahead and do it, (but don't overvoltage them) and just let the controller limit itself, if it's cold, you may get 62 amps out of it for an hour, but I don't think you can hurt the controller by making too many watts available to it.

The MPPT, over a year, will wring more power out of the panel than the C12 could .

lamplight

Re: parallel tristar mppt 60 with a Xantrex C12?

the more i think about it the more that sounds better. i had considered it as im only looking at 55 amps most of the time. the panel outputs about or under 5amps at 24v so i think thats what ill do. yea the tristar says it will just limit the amps if above 60 but _never_ go above 150v. thanks!

mike95490

Re: parallel tristar mppt 60 with a Xantrex C12?

Also, about the excess watts, unless your panels are on trackers, at sunrise, cold, you would have high voltage, but at such an off axis angle, you won't have full power, and thus, no excess watts.

lamplight

Re: parallel tristar mppt 60 with a Xantrex C12?

makes sense
new panel is on the way, thanks.