Battery backup, or inverter

[dperry324]

Hello all,

I have a question about battery configurations. I work in IT, and am around hundreds of servers every day. One thing we use a lot is ups battery backups. One we use is an APC brand. It differs fuse protection, as well as 120vac. It plugs in to standard shore power to recharge. I don't know if its cost effective like deep cycle batteries, inverters, and chargers. Just a thought.

[Dale M.]

THE battery back system of larger server farms are huge, some systems even rely in emergency generators to supply primary voltage for systems for long term, just like battery back up system in telephone industry.... Smaller systems usually available for single computer applications have enough capacity to keep system UP during short power glitch or to do a orderly shut down of system in case of power failure is going to be long term...

Inverter systems for travel trailers and RV generally are more robust in that the battery capacity may be any where for 5 to 20 times more the computer UPS and amperage loads may be again anywhere for 5-10 time larger and maybe not even constant such as refrigerators starting up and stopping or lights being switched on or off or electric bed warmers....

A computer UPS may be sufficient for bare minimal necessity if needs are very small but probably not robust enough for the average "camping adventure"...

Dale

[dperry324]

I had a feeling that the deep-cycle battery setup used by most here is prolly more robust than the computer UPS option. I do know that my (initial) needs are minimal so it might be a quicker, easier option for me. I expect to use an AC as the only thing on power, and it is likely to be only used when connected to shore power.

[GuitarPhotog]

If you plan to run A/C off batteries, you will need a very large battery capacity and a high capacity true sine-wave inverter, neither of which is your computer UPS.

A/C is notorious for high start up current draw, which can "bottom out" an inadequate inverter.

Search this forum for previous discussions of A/C and battery power.

<Chas>

[working on it]

What do you intend to power with it? And where is the battery backup or inverter to be located? I use an inverter for some LED lighting, or for my 120vac main cabin fan (high velocity, low amperage) as an emergency use provision only. I noted that the inverter not only sucks more power from my AGM battery than I liked, and, having the inverter located near my sleeping position, it also gives off heat (requiring more fan use). I also found out that it needed to be disconnected from the AGM when not in use; it drew power constantly, and drained the battery. I never considered using battery-supplied power for my A/C; too many amp-hours are needed = more weight/cost, i.e.> the large main cabin fan/inverter combo was my alternative. Or my on-board 2500 watt generator

[jss06]

I only use AC when I have shore power. Everything else is 12 dc. I just installed a 190 watt solar panel and mppt charge controller. I was able to get 25ah out of it while parked in a forest campground with only a few hours of direct sunlight. The rest of the day was in shade or overcast. Solar may be worth looking at.

[Shadow Catcher]

We have a 300W (will handle 600 for 15min) Morningstar Suresine inverter which is pure sine wave and is very stable. UPS wave forms are all over the map for square stepped and true sine. You can BTW hook a 12V battery to the inputs on a UPS.

[teddy]

Keep in mind, UPSes will not start without AC, so you need an inverter or genny to "boot" them. ( at least the desktop and 19" model we tried)

[dperry324]

Although my needs are minimal, as in only needing an A/C to run on A/C power, I think I will also be adding a battery/inverter/charger setup too. I think that I'd like to have the option of running the A/C, if only for a little while, when there is no shore power around.

[MtnDon]

Just keep in mind that a single battery won't provide much run time and that running a battery down more than half is not good for the battery.

[OverTheTopCargoTrailer]

Although my needs are minimal, I think that I'd like to have the option of running the A/C, if only for a little while, when there is no shore power around.

I got you covered bro, run your AC 24/7 on solar.


http://overthetopcargotrailer.blogspot.com/

[Kharn]

A Group 27 deep cycle battery will be around 110 amp-hours, most UPS are around 10-20 amp-hours.
Either one will run out very quickly powering an AC, instead I would plan on a generator for the AC and use windows and a fantastic vent when power isn't available and you can't run the generator.

[dperry324]

I got you covered bro, run your AC 24/7 on solar.
http://overthetopcargotrailer.blogspot.com/

Thanks! From a fellow Silicon Valley boy!

[highdesertranger]

so i scanned though that over the top cargo trailer that claims to run ac off of solar but didn't see many specifics. like how many watts of panels? how many ah of batteries does it take to run that overnight? the off grid people i know basically do without ac. i would like to see some specifics. highdesertranger

[MtnDon]

the off grid people i know basically do without ac. highdesertranger

There is no need to go w/o A/C when off grid, unless the off grid system is a bare bones setup. I have a friend in CA (in the Sierra Nevadas; hot enough in summer) who is totally off grid. No wires or pipes connect to the outside world. 1400 sq ft home. 2000 watts PV panels on two trackers. Does not even own a generator. They have a very normal home by all appearances, normal array of appliances, although all are newish energy efficient models and the range is propane. A programmable Sanyo mini split keeps it cool in hot weather and is also used as a heat source in winter.