back up battery upgrade

Messages
470
Location
KS
i bought a battery back up set up. can i put a bigger battery in the system. i dont realy care if it can go back in the box. back up 650. battery 6 in long, 3.5 tall, 2 in wide.
 
Messages
1,030
Location
dayton oh
old metal box? if so then yes. for long runs at max loads i add a fan in the bottom blowing in. and hole in the side near top with a fan grill. i found a line that went high in inverter mode only and used it to fire off a transistor to turn fan on only when running from battery. i used an led fan since i disabled the beeper. so if i see a blue glow under the ups the power is out. i have run up to 8d heavy equipment batteries. if you run it any length of time hook a charger to it to speed up recovery. i have several set up with lighter sockets and anderson powerpoles.
 
Messages
3,002
Location
USA
Some designs do not isolate the battery circuit from the power line. This means there may be 120 volts common mode on the battery wiring. They tend to be really inefficient at power conversion. Also in the cheaper ones there is little heat sinking, the battery is sized so to run down before the converter overheats.
 
Messages
25,430
Location
Upstate NY
Some of the expensive UPS have an option to add a 2nd module that is an additional battery. You could isolate the 2nd battery with a diode and it would allow power out but not in to 2nd battery. Keep 2nd battery charged with a BatteryMinder. The diode introduces 7/10s of a volt drop. Boats use this isolate the house battery from the starting battery.
 
Messages
36,135
Location
ME
It sounds like you have a 7 amp-hour gel cell. Beware if you hook up a "normal" car battery it will off-gas hydrogen which is mildly explosively dangerous and at times technically not allowed in living spaces.
 
Messages
44,711
Location
Ontario, Canada
Originally Posted by eljefino
It sounds like you have a 7 amp-hour gel cell. Beware if you hook up a "normal" car battery it will off-gas hydrogen which is mildly explosively dangerous and at times technically not allowed in living spaces.
Good point. I used AGM's.
 
Messages
10,001
Location
Waco, TX
Originally Posted by OVERKILL
Sure. I used to have an old SmartUPS 1000 that I had hooked up to two car batteries.
Same here - I have the next size (or 2) larger UPS - it had 4ea 6 volt batteries, all in series for 24v. I just wired two Group 24 Marine/deep cycle batteries together in series and used 8 or 10 gauge wire to extend the current wiring out to where it can be hooked to the batteries.
 

JHZR2

Staff member
Messages
45,335
Location
New Jersey
Generally yes, but on an unknown UPS, you do it at your own peril. I'd be sure to add fuses near the battery terminals,
 
Messages
25,046
Location
ON, Canada eh?
Originally Posted by OVERKILL
Sure. I used to have an old SmartUPS 1000 that I had hooked up to two car batteries.
I have this setup as well with my server. I need run time but not a ton of amps so this is why I did it. As long as you don't overload what the UPS is capable of you can extend the run time by adding batteries in parallel.
 

red7404

Thread starter
Messages
470
Location
KS
WOW all that info is great. thanks guys. i had a friend that knew all that tech stuff. and i did go throu the electronics school over 25 years ago. but time degrades the brain cells yes i think ill add fuses at the battery, and a disconnect.
 
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