Best apc ups for small load

linuxrunner

I have access to free apc smart ups models from 750-2200 including both new and old models. I have been using one for a battery charger/inverter in a small camper. I have 2 50ah batteries attached to an apc 750 right now but my problem is I have very low power draw. I have LED lights and a few phone chargers running and that's about it. Total is about 50w. I picked the smallest ups thinking it would be the most efficient at low power levels but now I am wondering if perhaps a new model 1500 might be better.

Estragon

What's the problem with the small UPS and small load (eg slow recharge?, not detecting small loads?).

Generally speaking, bigger inverters are less efficient with relatively small loads. I did note that this model supplies a stepped AC waveform though, which could be an issue for some loads (eg wall warts may run hotter).

For phone chargers and led lights, running off 12vdc is often possible, and can be more efficient than any inverter.