Forum Discussion

BFL13's avatar
BFL13
Explorer II
Apr 27, 2020

UPS Ideas ?

This could be for an RV where there have been posts about TV receivers etc getting knocked out by slow switching 120v power inputs. In this case it is in the stick house. I have jury-rigged something using RV equipment, but looking for a better answer.

The internet to the house has two things that need plugging into 120v, so when we have a power outage we lose the internet. This can be bad for working at home situations, eg. The laptops, etc, have their own batteries of course.

I have rigged up a 27DC battery with a 300w MSW inverter, and plugged the two things into that. I have a spare deck mount converter on the battery and the converter is powered by stick house 120v. So that all works for being a UPS. However, the converter fan comes on every so often and is annoying. The inverter's fan is quiet so no problem there. It all gets as much air as possible.

So what do people do who know more about all this tech stuff? Thanks for any ideas.

I did run a kill-a-watt on it all to see what the power needs are. (all figures rounded off and averaged where they bounce around some)

1. Phone company equipment (two plug-ins) in stick house receptacles- total- 15w, 28VA, PF 0.55

2. In inverter receptacles- 14w, 31-40VA, PF 0.3- 0.46 jumping around.

3. All running off inverter and from the converter's 120v input-
45w, 58VA, PF 0.76

So drawing about double what it takes straight (58 vs 28 VA), but not worried about that increase in the hydro bill :) . It is more about the converter's fan noise.
  • BFL13's avatar
    BFL13
    Explorer II
    Apr 27, 2020
    Looking at some UPS units. Not too clear how long the battery lasts, eg.

    This one says it has a sealed lead acid battery and you can get replacement batteries for it

    "APC 1000VA UPS Back UPS Pro mini tower backup power supply ..... Hot swappable batteries Ensures clean, uninterrupted power to protected equipment while batteries are being replaced"

    "Hot swappable" means what exactly? Are there two in it so it keeps running while you swap out one at a time? Can you recharge the battery after the power comes back on?

    I have seen those "power box" things that seem to do what I want that you can recharge, but I don't know about fan noise with them if any.
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Apr 27, 2020
    I have a couple of Tripp-Lite UPS's in our cottage to protect the more sensitive electronics and keep them alive through power outages until the backup generator kicks in if necessary. In our motorhome, I use an APC UPS that's had the original 12-volt gel cell removed and uses the coach 12-volt battery system instead. The UPS switches our satellite receiver, TV, Internet equipment, and my wife's medical equipment from shore power to the UPS within one cycle, so there's no service interruptions. I've also disabled the alarm on the UPS so it's not annoying us every time we pull the shore power plug before heading down the road.
  • BFL13's avatar
    BFL13
    Explorer II
    Apr 27, 2020
    That set-up using a different battery could work for me. I see this gizmo, but it is not clear if its recharger could keep up with the draw of the phone company's equipment via its inverter so I could just leave it plugged in same as my jury rig.

    I don't know if the modem would get knocked out in "one cycle" or not. It takes a minute or two to get the internet back once it has power. Leaving it on the inverter all the time avoids that.

    https://www.canadiantire.ca/en/pdp/motomaster-eliminator-powerbox-600-0112002p.html
  • STBRetired's avatar
    STBRetired
    Explorer
    Apr 27, 2020
    I have an APC UPS at the S&B to keep my internet connection alive. Was not all that expensive. I don't recall exactly what model it is as am not there at the moment. Will keep my connection up for about 18 hours with no power.

    Hot swappable can be done either of two ways. The unit can have two batteries, where you can pull one out to replace with a fully charged one while it runs on the other, or it can have an internal LI battery that will keep the UPS running for about 30 seconds while you swap the main battery. In any case, you must have a fully charged battery to put in.

    If I regularly experienced power outages of 12 hours or more, I would look into disconnecting the internal battery and using a group 27 AGM instead.
  • rk911's avatar
    rk911
    Explorer
    Apr 27, 2020
    fj12ryder wrote:
    Buy a commercially made UPS, no fan, no noise, no sweat.


    +1
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Apr 27, 2020
    BFL13 wrote:
    That set-up using a different battery could work for me. I see this gizmo, but it is not clear if its recharger could keep up with the draw of the phone company's equipment via its inverter so I could just leave it plugged in same as my jury rig.

    I don't know if the modem would get knocked out in "one cycle" or not. It takes a minute or two to get the internet back once it has power. Leaving it on the inverter all the time avoids that.

    https://www.canadiantire.ca/en/pdp/motomaster-eliminator-powerbox-600-0112002p.html


    No, a modem will not be knocked out on a less than one cycle switch. Very few electronics are. Some very expensive lab equipment can be sensitive to the near instantaneous switchover, but that's about it.
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    Apr 27, 2020
    A few years back, I did some research for a friend on residential/light commercial UPS for a friend. The bottom line is "you get what you pay for".

    •Buy a Pure Sine Wave UPS. The cost difference between MSW and PSW should not be that much (10%-25%) with modern electronics ! Anuone charging more either is making big profits or is making a very old design. (10 years in electronics is "very old".)
    • Replacement batteries are almost as much as a whole new UPS !!
    • ALL UPS are designed to run for a LIMITED AMOUNT OF TIME, probably under 1 hour, but possibly as short as 15 minutes. Buyer beware. Read the specifications. (Short time mean smaller battery, lower cost, and less money invested in high heat protection.)
    • "Switch over time" is an issue. The best commercial UPS are "online". That is, 100% of the time, the load is running off of the inverter. Battery charging is independent of the inverter. $$$ !!

    If you don't mind the extra wiring (build a box to hide it), buy a pair of AGM golf cart batteries and a 500w-1000W PSW inverter. Buy a separate battery charger. You are in business and will have a very long "ride through" time.
  • BFL13's avatar
    BFL13
    Explorer II
    Apr 27, 2020
    So the APC UPS using the MH house battery bank does not need to be left plugged into a charger to keep it running when 120v is still on. It switches to inverter fast enough.

    --------

    EDIT--besides the modem for switching time, there is the gizmo the modem plugs into that converts from the fibre line to the house. Don't know about switching time for that. OK? That converter also is plugged into 120v, making the two things needing 120v.
    ---------

    The OEM battery in the UPS recharges once the power comes back on? Or if you use a different battery, you recharge that with your converter or solar.

    What did you have to do to connect the external battery to where the internal battery was?
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    Apr 27, 2020
    theoldwizard1 wrote:
    If you don't mind the extra wiring (build a box to hide it), buy a pair of AGM golf cart batteries and a 500w-1000W PSW inverter. Buy a separate battery charger. You are in business and will have a very long "ride through" time.


    Forget "extra" wiring ! The Samlex EVO-1212 has an "online" mode ! The only thing you need is batteries.

    This option is also called “On-Line UPS Mode” (UPS stands for Un-interruptible Power Supply). In this mode, the Inverter Section of the EVO is the PRIMARY DC-AC source of power. The AC input source is the BACK-UP source of AC power. In this mode, even if qualified AC input is available (within the programmed voltage and frequency limits), the EVO will still operate in “Inverting Mode” and AC output will be provided by the Inverter Section as long as the batteries are in charged condition above the specified programmed value of low battery voltage

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