I don't recommend using a regular automotive (wet) lead-acid battery for UPS gear. I've done this in the past, and the UPS will just boil away the electrolyte over time as sealed (SLA/VRLA) batteries use a higher floating charge voltage than a flooded/wet cell (in addition to other disadvantages). You can monitor and add water regularly if you wish, but I've just started buying large sealed lead acid batteries--the same type that UPS gear comes with. The 4x75AH batteries on my main UPS are just about the size of a standard car battery, and they make them (much) larger still. They're a little more expensive for sure, but they are the right tool for the job.
As far as voltage, it depends on the size of the UPS. I have a 650 that uses a single 12v battery, 1000-1500VA units that use a 24v system, 2000-3000VA units that use 48v, and even 5000 and 10000VA units that use 192v and 288v, respectively. -----Original Message----- From: hardware-boun...@lists.hardwaregroup.com [mailto:hardware-boun...@lists.hardwaregroup.com] On Behalf Of DSinc Sent: Saturday, October 19, 2013 5:08 PM To: hardw...@lists.hardwaregroup.com Subject: Re: [H] Car Battery with UPS Winterlight, I will totally defer to your experience; even though everything I have learned says "NO." Different strokes for different folks. I am not willing to allow common (auto)/special (please define) batteries into the space I live in. Yes, my security system uses a 'sealed' 12v battery. I change it as necessary and just live with it. I have never had a security system before. OK, maybe not all ups's have 2 batteries. I was replying to you my life with APC since 1995. No harm, no foul. All of my ups's have 2ea=12vdc batteries. Sorry. This is my world. My security system has one /sealed/ 12vdc battery. My HD Road King has one /sealed/12vdc battery. My 1949 Indian has one /lead-acid/ 6vdc battery (as soon as I find it!). My Lawn tractor has one /Lead-acid/ batteryone 12vdc battery. On 10/19/2013 17:43, Winterlight wrote: > > Not all UPS have two batteries. Yea, so what? I have not figured out how APC gets useful current out of one 12vdc battery! I'll give this point to you. Unless you know the chemistry, you can create problems. Just saying! > I have a old APC 900VA = 500watts that uses a single 12 volt battery. > A gas cloud explosion is extremely unlikely, particularly in a > ventilated room. I have had two 850 Cold Cranking Amp car batteries > ... a Motocraft and a Interstate that have been sitting in my office > for years. At times I have had/used them in my bedroom. They are > hooked up to a solar trickle charger and I use them with an invertor > whenever something like a wild fire kills the power for an extended > period of time. I have never had a problem. I live in a area where the > windows are always open and most of the time I have a fan running to > combat humidity. I suppose you get to use your science for your > current situation. > > At 03:45 AM 10/19/2013, you wrote: >> Well, yes, I suppose you could use a pair of auto batteries. Yes, you >> would need two in series (24vdc). But why? >> Don't auto batteries bubbleoff hydrogen gas as they charge? Why would >> you wish to create a gas cloud inside a home? I'm pretty sure that >> ups's still use emc power contactors to do conversion switching. One >> spark and boom! >> Perhaps some of the newer battery chemistry's my help avoid this >> trouble, but I wonder. I only charge my auto/lawn tractor batteries >> outside in the driveway. >> Just a thought. I'll defer to the experts, however. >> Duncan >> >> On 10/18/2013 21:34, Winterlight wrote: >>> Anybody here ever hook up a car battery to a UPS? >>> >> > >
