Morningstar Prostar 15A with AC/DC Adapter for input

Thank you for the reply!

Yes, I did consider DCUPS-30 and some other products from Powerstream, but would prefer a more powerful and sophisticated charger.

Also, saw the manual where it mentions the use of an external "current limited" power supply for testing. At another place it specifically tells not to use anything other than solar as input, but I was not sure of the reason. Thanks for bringing up the ripple factor!

Thank you! I will go by your warning and would consider a more specialized product than the solar charge controller. I looked at the product that you posted, but that is just a charger. Not sure if that can be made to function as a DC UPS; no load switching and low-voltage disconnect.

"I have a few low-power DC loads that needs to stay on 24x7."


 "So, I was thinking of using a 12V DC UPS System to power those devices (can accept 8V DC to 21V DC)."



In review, I am just a little confused.
You want to "build" your own 12 vdc nominal supply UPS utilizing a 120 vac grid circuit?
You want to use that 120 vac circuit to power all of the 12 vdc loads while the utility power is up but, you want the UPS to take over 12 vdc loads when the utility is down and you want a low voltage dc cutoff?

If you could size the battery pack large enough it could go for days without needing to recharge or "cutoff."

Two - Trojan T-105's wired in series will provide 220 amp hours at 12 vdc nominal at the 20 hour rate. Four = 440 amphours and so on.

Somebody is bound to make a charger that has input of 120 vac to recharge if necessary and maintain a 12 vdc nominal battery pack while still being able to power the dc loads.

http://www.directdepot.net/product_info.php?products_id=8965

Just connect your 12 vdc loads to the battery pack.

Of course I have no way of knowing just what your exact situation is as far as; amphour requirements, days of autonomy or, any budget restraints. Do each of the loads have their own battery?

How long do "black outs" last? A week? Just size the battery pack to last 10 days.
With the above charger, "brown outs" might not matter because it has such a spread on the ac input voltage.