Announcement

Collapse
No announcement yet.

UPS Battery Time Question

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • UPS Battery Time Question

    I'm looking to run a wireless modem and a wireless router in my car...the easiest solution I have to keep them juiced after the key is out is to run them off a large UPS, like this APC model at compusa. I can't find any info on ther site about how long it will run for...the needs of the router can't be anything compaired to the full blown computers they base their numbers on, so can I expect some long battery life because of that? The model say 1000 VA and 600 W, and the router needs 12V @ 1.0A, and the modem is something like 12V @ 0.75A...what kinda formula do I need to calculate an average time? Do I just divide the 1.75 into 1000 and get 571 minutes? Would be nice if it was that simple!

    Well, just hoping to see if anyone knew, or had experience running a router strictly off a UPS. Thanx!

  • #2
    What about buying a cheaper model, and just changing to a bigger batt?

    Comment


    • #3
      InTheWayBoy, you'll be using the AC to DC adapters to power the router and modem, correct?

      If yes, use the amperage rating on the AC side to do your calculation. Basically do this:
      110V * (amperage rating of router + amperage rating of modem) = A

      Amount of battery time available: (600W / A) hours.

      I assumed you lived in the US so I used 110V.
      EPIA Nehemiah M10k, M1-ATX, 20GB 4200 RPM 2.5", 256MB RAM, Win XP Home, Gyration RF Keyboard & Mouse, Zoltrix Nightingale Optical 4.1 PCI Sound Card, Lilliput 619GL-70NP, XM-PCR w/ optical upgrade, Garmin GPS-25LVS, Microsoft MN-710 USB Wireless NIC

      Comment


      • #4
        110 (1.75) = 192.5

        600 / 192.5 = 3.11

        So I'm looking at around three hours then?

        eCar...that was my original plan, but after seeing how much a nice Optima battery would cost it looks like this is the simpliest way...three hours, if that is right, is about what I was shooting for!

        Comment


        • #5
          No, you were doing it on the DC side. Unless both the DC and AC side have the same ratings (which is UNLIKELY) then that calculation is wrong.

          Look at the adapters, the AC ratings should be printed on them.

          Also, have you thought about using a battery tank instead. Rather than a UPS you might be better off with a battery tank.
          EPIA Nehemiah M10k, M1-ATX, 20GB 4200 RPM 2.5", 256MB RAM, Win XP Home, Gyration RF Keyboard & Mouse, Zoltrix Nightingale Optical 4.1 PCI Sound Card, Lilliput 619GL-70NP, XM-PCR w/ optical upgrade, Garmin GPS-25LVS, Microsoft MN-710 USB Wireless NIC

          Comment


          • #6
            Originally posted by InTheWayBoy
            I'm looking to run a wireless modem and a wireless router in my car...
            What kind of network are you trying to set up here? I'm trying to decide on a wireless setup, but the common options don't accomplish what I'm looking for. Just wondering what you're trying to do here. What kind of wireless modem is it?

            Why are you trying to calculate the time you can run just the router off the UPS? Won't the computer also be on?

            And if you're looking to keep things running with the key out, you could just hardwire your inverter to your battery, or to avoid a dead battery go with my favorite option, the auxiliary deep cycle. Did you check eBay for the Optimas? I got two off eBay for $109 each, I think they're regularly about $175. Add an isolator and you can run EVERYTHING (stereo too) for three hours without the key (and run the router alone for WAY longer).

            And if you wanna get crazy you could put the UPS between the battery and equipment, for even more time. But obviously that's extraneous cost you're not looking for. I'm just thinking out loud.
            95 Chevy G20 Vroom Boom Room
            ...with a whole bunch of nifty ****... go check it out: VanDomain Page

            Comment


            • #7
              Here is what I make of it:

              First of all, you can't just divide the max power rating (600W) by what you will be using, and end up with minutes.

              Anyway, you have 2 devices that both run at 12VDC for a total of 1.75A (21W).

              You are going to use AC-DC transformers to run the devices. Let's say they are 75% efficient. So, they will draw about 28W from your UPS.

              The UPS you linked to is 1000VA. According to this page, a similar UPS (BR1000) gets 1h36m runtime at 50W draw. Now notice that this UPS is most efficient at 100-200W draw. At the max power rating (600W), efficiency drops off. At the low end (50W) it drops off also. Based on this, I guess that you will get about 2h15m, or maybe 2h30m max.

              Comment


              • #8
                I think he's trying to create some kind of Personal Area Network. So he can browse the internet with his PDA, for instance, while roaming outside of his car.

                Just a guess. If he is then I've been thinking about the same thing my self. Maybe we put our heads together.
                EPIA Nehemiah M10k, M1-ATX, 20GB 4200 RPM 2.5", 256MB RAM, Win XP Home, Gyration RF Keyboard & Mouse, Zoltrix Nightingale Optical 4.1 PCI Sound Card, Lilliput 619GL-70NP, XM-PCR w/ optical upgrade, Garmin GPS-25LVS, Microsoft MN-710 USB Wireless NIC

                Comment


                • #9
                  Since it looks like I've got some people attention with this, I'll explain more!

                  I live in Jacksonville, FL and we're are one of the first markets to get ClearWire, which is essentially wireless internet...they accomplish this by using their own towers to distribute the signal, which is picked up by their proprietary modem. Each tower covers something like seven miles, so it's not all it's cracked up to be, but better than nothing! Thankfully they haven't screwed it up by requiring tons of software to run the thing...in fact, there is none! All you do is plug in a CAT5 cable and you're done!

                  I run a small on-site repair company, and lots of times our customers don't have broadband. This gets to be really annoying when I have done everything but still need to download a 40MB+ driver file. So what I was thinking is run the modem and a wireless router in my car, which would distribute the wireless internet connection via the router...then all I would have to do is install a wireless adapter if they don't already have one and then I would be online!

                  Most service calls last between two to three hours, so I would like to find something along that level. I'm not really interested in a big production, cause that just means I'll never get it done. I've looking into some of the previously mentioned ideas, and just never go a good enough explanation. The vehicle is a Honda Element, which comes with a pretty week stock battery. Also, there is no power to the ports when the key is out. I would prefer to do something modular like the UPS, or something that I can at least install and remove easily for when I don't need it.

                  If what eCar is saying is true, then I think I might just stick with the UPS...I like the idea of the Optima and an isolator, but how would I hook all that up? My understanding would be that I would hook the batter up to the isolator, and the what? Does that have to hook back up to the car's electrical system somehow?

                  The only thing running off the UPS while the car is off would be the modem and the router...sometimes I might plugin in my laptop if I'm just chillin somewhere, but not very often.

                  I appreciate all the help fellas, and I would be glad to help with anything if possible. I don't think ClearWire is going anywhere else soon, and truthfully the coverage isn't all it's cracked up to be...but what else is new right? And just so you know, it's 1.5MB for $35 a month with a free modem when you sign up for twelve months. The modem is simple...power and ethernet. No config, no software...sadly no external antenna port either. Since I get pretty spotty signal I'm gonna call them and see if they offer something more powerful, but I doubt that they do. Of course, a mobile hot spot is not really their intended use.

                  Comment


                  • #10
                    Originally posted by InTheWayBoy
                    So what I was thinking is run the modem and a wireless router in my car, which would distribute the wireless internet connection via the router...then all I would have to do is install a wireless adapter if they don't already have one and then I would be online!
                    Ah, I knew you were trying to create something like this. I've been thinking to do kinda the same thing. What I envision is to have my carputer to serve as an internet gateway to my wireless devices, either PDA or notebook pc. My carputer needs to be connected to the internet first, of course. I'll do this through the cellular network. See the problem yet? Yup, internet service through cellular network is still quite expensive. For the city I live in to get something like ClearWire is like hoping for the winter to bring some snow. It's just not going to happen in Central California. Although we are getting the 10th Campus of Univ. of CA. So we'll see. It might snow after all. Anyway, that's why my vision is still.., well, a vision.

                    If what eCar is saying is true, then I think I might just stick with the UPS...
                    I don't think the calculation will ever be accurate enough if it's done using the rating on the DC side. You're planning on using a UPS, that tells me that you will be powering the modem and router through the AC adapters. Then it's the rating on the AC side that needs to be used in the calculation.

                    I like the idea of the Optima and an isolator, but how would I hook all that up? My understanding would be that I would hook the batter up to the isolator, and the what? Does that have to hook back up to the car's electrical system somehow?
                    Yup, the idea is your car's battery charger will charge both the car's battery and the Optima. The isolator governs the charging current. The positive poles of the batteries individually hook to the isolator and the isolator hooks to the battery charger.

                    sadly no external antenna port either.
                    Most modems/routers are hackable. Some of their PCB even already have predrilled holes for antenna hook ups. Of course, hacking will always be equal to warranty voidance by the manufacturer. Maybe you can find a way to acquire a hackable second unit.
                    EPIA Nehemiah M10k, M1-ATX, 20GB 4200 RPM 2.5", 256MB RAM, Win XP Home, Gyration RF Keyboard & Mouse, Zoltrix Nightingale Optical 4.1 PCI Sound Card, Lilliput 619GL-70NP, XM-PCR w/ optical upgrade, Garmin GPS-25LVS, Microsoft MN-710 USB Wireless NIC

                    Comment


                    • #11
                      On the cellular internet side, I have SprintPCS, and with a USB cable I can use my phone to connect to the internet for free! Now all is not well...it violates their terms of service, but they don't mess with you unless you go over a certain amount. I don't remember exactly...but I wanna say it was like 100MB. It's only something like 120K, but it's better than nothing! And at that rate, you probably have no problem avoiding the limit! I have it as a last resort...

                      Would the charging of the two batteries put more strain on...whatever charges them? I never understood how all that worked...an alternator or something? Cause the element already has a lame battery system, and I run things off both power plugs as it is...if I had to would upgrading the alternator or something else help?

                      Also, when running an battery and an isolator how do I hook up an invertor like I use in the cigarette power ports? I had one before that had an aligator clip attatchment...would that be all I would need to do?

                      I haven't looked into the modem too much yet, as I still might return it...but it's nothing I've ever seen before...it's tall and skinny so I would guess it's just a long PCB and might have something to work with. But if its not already there then its outta my hands. Since I might resell it for them I'm sure I could score some test units.

                      I really appreciate all the help so far, thanx again!

                      Comment


                      • #12
                        Originally posted by InTheWayBoy
                        On the cellular internet side, I have SprintPCS, and with a USB cable I can use my phone to connect to the internet for free! Now all is not well...it violates their terms of service, but they don't mess with you unless you go over a certain amount. I don't remember exactly...but I wanna say it was like 100MB. It's only something like 120K, but it's better than nothing! And at that rate, you probably have no problem avoiding the limit! I have it as a last resort...
                        I just signed up with similar service vith Verizon. I'll see how it works with them.

                        Would the charging of the two batteries put more strain on...whatever charges them? I never understood how all that worked...an alternator or something? Cause the element already has a lame battery system, and I run things off both power plugs as it is...if I had to would upgrading the alternator or something else help?

                        Also, when running an battery and an isolator how do I hook up an invertor like I use in the cigarette power ports? I had one before that had an aligator clip attatchment...would that be all I would need to do?
                        Yup, certainly would. However, usually the alternator has about 20% - 30% extra headroom. I think I read this on the12volt.com it's a forum for mobile electronic installers. This excess power could be used to power a small 12V 7Ah gel battery (like Yuasa NP7-12 gel battery). You would power your modem and router directly, no adapter needed, no inverter needed. Here's when we would use the rating on the DC side. You said 1.75A total, right? 7Ah/1.75A = 4 hours. How about that?

                        I haven't looked into the modem too much yet, as I still might return it...but it's nothing I've ever seen before...it's tall and skinny so I would guess it's just a long PCB and might have something to work with. But if its not already there then its outta my hands. Since I might resell it for them I'm sure I could score some test units.
                        Test unit would work. I've seen some hacks where folks just desoldered the existing antenna, soldered on an RF connector, then hooked it up to an external antenna. Perhaps you could go this way.

                        I really appreciate all the help so far, thanx again!
                        My pleasure. The mind is a too beautiful thing to waste. Gotta keep it exercised. And this forum accomodates that. Isn't that great?
                        EPIA Nehemiah M10k, M1-ATX, 20GB 4200 RPM 2.5", 256MB RAM, Win XP Home, Gyration RF Keyboard & Mouse, Zoltrix Nightingale Optical 4.1 PCI Sound Card, Lilliput 619GL-70NP, XM-PCR w/ optical upgrade, Garmin GPS-25LVS, Microsoft MN-710 USB Wireless NIC

                        Comment


                        • #13
                          Yeah...there is quite a bit a information here to tax the brain

                          Comment

                          Working...
                          X