Battery backup (UPS) for computer while on house batteries?

I had heard even some people's DVR's and Sat receivers were rebooting whenever power source auto-switched..

i think if you go re-read those posts
you will find that most were switching from generator to shore power
or vice-versa
generators "wind down", which means there is a voltage drop-off, before the transfer switch disconnects
the Sat box, shuts down on low voltage, but the ATS has not switched out to the inverter or shore power until the voltage lag gets lower (like less than 90 volts)

the other problem is some combo units (inverter/charger) have a slight time in mode delay in mode changing going from charge to invert functions
a dedicated always on inverter and separate converter/charger
Eliminates all those problems..there are NO relays or timers involved

jerseyjim wrote:
Seems to me, if the "house" current fails, the laptop immediately goes to battery power...which should give you a good 2 hours of computer time. Even then, if the cg power goes out you can always start your generator (if you have one...and the cg permits generator usage)

Unless you run your business from the RV, that should be enough computer time during a day.....IMHO....


Using the inverter will drain your house batteries really fast, so be careful there.

the OP did say "tower" computers, Mac and Win PC..NO battery
not laptops...

Chris,

You are asking for more trouble than you can imagine. Go back up the page and read DrewE. If you power the computers off a single inverter that is sourced by the house bank, you have a chance, (only a chance) but you had still better test things. You are about to get bitten by the infamous Switcher Bug. There is a defense but it is expensive. Few things have real transformers any more. These are expensive iron and copper parts that avoid aliasing. Aliasing is when two switching devices get on each others case and you can end up with results that defy any simple explanation. If you have two, you may have a problem. If you have three there is a very good chance you will have a problem, but if you have four stacked together it is nearly a certainty.
Your converter is a switching power supply.
Your UPS has a switching power supply.
Your inverter is a switching power supply.
Your computer has a switching power supply.

You only need two of these to disagree and nothing works. The house bank will be a big enough buffer to usually (not always) keep the things that it and the converter power happy, but past that.....
Even if you blow the extra money for a "Pure Sine" inverter, you can still have problems.

Good luck guy.

Seems to me, if the "house" current fails, the laptop immediately goes to battery power...which should give you a good 2 hours of computer time. Even then, if the cg power goes out you can always start your generator (if you have one...and the cg permits generator usage)

Unless you run your business from the RV, that should be enough computer time during a day.....IMHO....


Using the inverter will drain your house batteries really fast, so be careful there.

travelingbard wrote:
Will the better inverters switch fast enough to keep constant power to the 110 outlets if the surge protector kills power (low voltage or something triggering it)? If so, then I'm good to go without the need for a UPS, but I had heard even some people's DVR's and Sat receivers were rebooting whenever power source auto-switched...

that depends on the units being used and the sensitivity of the devices

like it was said, an inverter and your RV batteries make one large UPS
IF you set it up correctly

i have two inverters one for the fridge and high power, one for the electronics
the TV , laptop , bedroom alarm clock ,etc are always powered by inverter
the batteries are keep charged by a 100 amp converter
shore power or generator powers the converter to charge batteries, along with 505 watts of solar power
the batteries always power the inverters
one giant UPS..
i can flip breakers, pull shore cord, shut off generator
nothing beeps or blinks or burps
the inverters are always on 24/7-52weeks
unless i have shut down to work on something

I use a couple of the POWERWARE (Now EATON) RM5125 SMALL UPS UNITS in connection with my Emergency Radio OPS when on WX and other ALERTS using my OFF-ROAD POPUP trailer setup. My computers are LAPTOPs but do have WIFI printers and other 120VAC items on all the time when we are activated.

These produce 1500WATTS of real clean looking 120VAC and has internal batteries. When these were new they would last 4-5 hours but now I'm lucky to get 45 minutes ouot of them...

They do have external BATTERY CONNECTION PLUG on them but I never looked into what DC VOLTAGE they would need.

The items I have plugged into these units continue to operate when the shore power is disrupted and then when I get my INVERTER system up and going then they still continue to provide 120VAC from the 120VAC INverter side and recharge the internal batteries. They also beep alot as described above haha...

It does keep me on the air with my radio while I get things setup again when the shore power goes down...



Roy Ken

Your RV is the UPS. Just get an inverter to complete the package.
Forget those little portable UPS units.

Will the better inverters switch fast enough to keep constant power to the 110 outlets if the surge protector kills power (low voltage or something triggering it)? If so, then I'm good to go without the need for a UPS, but I had heard even some people's DVR's and Sat receivers were rebooting whenever power source auto-switched...

I actually use UPS's extensively, I have them at home on everything and manage hundreds of them at work. However I really do not like the idea of using them in the trailer. In my opinion there are more negatives than positives:
1) they are very heavy and I do not want to overload the trailer
2) they are big and difficult to mount/stow etc.
3) when you are off shore power but still plugged in with an inverter they will draw a load to stay charged. Charging a battery from a battery is not efficient
4) when you are off shore power and forget to turn it off (which could be frequently) the battery will drain and UPS batteries are like car batteries, they are not meant to fully discharge. My experience is a new UPS can only tolerate a couple of full discharges and than it is landfill. An old UPS will be dead after a single full discharge
5) they are really noisy. It drives me nuts when I am in a LAN Room and all I hear is a dozen of them beeping no stop... drives me completely bonkers. The idea of hearing that beep every time there is a brown out, black out, I forget to turn it off before pulling shore power etc. would make me want to throw it out the window.

If you're running a UPS on "house battery power", you obviously have an inverter. Why not just run the computers on the inverter all the time? If you're connected to shore power, the converter/charger will power the inverter, and if it cuts out, the house batteries take over the load. Putting another battery and charger and inverter in between the one you have and your load seems rather counterproductive to me.

I suspect UPSs are not used for the balanced/isolated power supply in a studio mainly because the power most put out (when running off their batteries) is none too clean and would cause all sorts of audio noise. Most UPSs, at least most relatively inexpensive ones, are MSW output—fine for computers with switching power supplies, but inducing noise in audio signals.