High end UPS vs cheap car battery?

Caporegime
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I've been looking for a UPS with a much larger capacity after the 2 day power outage that we just had because of the flooded substation.

Now looking at APC UPS systems, they don't actually state their capacity, but as an owner of one of their 400W/700VA UPS systems I know that the battery in mine takes up a tiny amount of the UPS space so the capacity is low. The battery is only 12v 7Ah which you can buy off amazon for about a tenner.

Is it better for me to buy a higher end UPS or spend the money on a 12v 220Ah car/leisure battery and connect it to my cheap UPS?
 
Soldato
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Well, you know you are on a forum...
So everyone will tell you to spend more, buy the best, take no chances...etc etc.

Me personally, I would be buying a healthy, second hand truck battery from a scrapyard. Take a multi meter and check it out first. won't cost you hardly anything. hell, even get a few. Some of those badboys are upwards of 150 amp hours
 
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Associate
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The power output from those cheap gennies is often very poor though - your PSU won't thank you for it!
 
Soldato
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The power output from those cheap gennies is often very poor though - your PSU won't thank you for it!

The PSU won't know because the power is going through a UPS which will smooth out the power before it gets to the PSU

Like I said I have the aldi generator and I think its rated for 800w? I use it exclusively with a 1000w rotary polishing machine and it handles it just fine. 100+ hours I've put on it of very stressful loading. at £60 I considered it "disposable" so pulled 1000w through it but it's still going strong!
 
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Soldato
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A generator in my bedroom? No thanks.

defender-20mtr-cable-extension-reel-230v-13a.jpg
 
Don
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I've been looking for a UPS with a much larger capacity after the 2 day power outage that we just had because of the flooded substation.

You will struggle - as generally UPSes aren't designed for long term use, in most cases UPSes are just used to smooth the period between mains power failure and a generator kicking in.



Now looking at APC UPS systems, they don't actually state their capacity, but as an owner of one of their 400W/700VA UPS systems I know that the battery in mine takes up a tiny amount of the UPS space so the capacity is low. The battery is only 12v 7Ah which you can buy off amazon for about a tenner.

Guessing it's a BackUPS series, in which case I would say upgrading the battery is almost certainly out of the question (The inverter etc are likely not rated to run 24/7)


Is it better for me to buy a higher end UPS or spend the money on a 12v 220Ah car/leisure battery and connect it to my cheap UPS?

Personally I'd just buy a much larger high end unit - 3000VA is about the biggest you can go without requiring hard wiring iirc. Worth looking on ebay as you can often get larger ex enterprise UPSes that have been refurbed with new batteries.
 
Don
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The PSU won't know because the power is going through a UPS which will smooth out the power before it gets to the PSU

But that would require you to also have a decent UPS (i.e. line interactive, or fully online) - a cheap BackUPS or equivalent will just switch to battery if the incoming supply is rough (as opposed to a line interactive that will use the battery to boost/trim the voltage, and an online that runs completely of battery and just uses the poor mains to charge the battery)
 
Soldato
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It's possible to get battery packs for UPS systems to increase the backup time to take standard 7ah/9ah batteries (external chargers required for a few packs) but how much power and for how long would you seriously want?

If you bought a 3kVA online UPS with 5 additional battery packs you'd probably get about 12 hours of run time at 1/4 load, but that would be 18U of rack height, over 200kg in batteries and cost £1000's.

UPS's are designed for short term use either for short power outages, stabilising power, safe shut down for long term outage or back up power to allow a generator to start up. In some African countries it's quite common to have a home inverter wired up to large capacity batteries but their power requirements are much lower.

Due to how infrequent we get power cuts, for home use it's probably cheaper to book in to a hotel for a few days.
 
Caporegime
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You can't just leave generators outside in the garden, they aren't weatherproof. They're noisy and it has been pretty much impossible to buy petrol for the last couple of days because obviously with no power, and panic buying all the petrol stations in the area are shut.

It's possible to get battery packs for UPS systems to increase the backup time to take standard 7ah/9ah batteries (external chargers required for a few packs) but how much power and for how long would you seriously want?

If you bought a 3kVA online UPS with 5 additional battery packs you'd probably get about 12 hours of run time at 1/4 load, but that would be 18U of rack height, over 200kg in batteries and cost £1000's.

UPS's are designed for short term use either for short power outages, stabilising power, safe shut down for long term outage or back up power to allow a generator to start up. In some African countries it's quite common to have a home inverter wired up to large capacity batteries but their power requirements are much lower.

Due to how infrequent we get power cuts, for home use it's probably cheaper to book in to a hotel for a few days.

The impact of power cuts is severe though so even if they don't happen often they are worth mitigating against, 3 days without having internet, telephones, or computers makes communication virtually impossible, I can't work or do my coursework, due to the power cuts I had to contact my uni to get an extension because I missed the submission date because I couldn't upload my coursework.

I've actually measured my power use and done the maths and my computer equipment is using approx 180W in low usage mode so a single £75 120Ah battery would last 8 hours ignoring inefficiencies. I don't know where you got the figure of thousands from?

You will struggle - as generally UPSes aren't designed for long term use, in most cases UPSes are just used to smooth the period between mains power failure and a generator kicking in.

Guessing it's a BackUPS series, in which case I would say upgrading the battery is almost certainly out of the question (The inverter etc are likely not rated to run 24/7)

Personally I'd just buy a much larger high end unit - 3000VA is about the biggest you can go without requiring hard wiring iirc. Worth looking on ebay as you can often get larger ex enterprise UPSes that have been refurbed with new batteries.

To clarify I'm not talking about running the UPS at max load for 24 hours, I'm talking about using the computer at a low level of intensity for a few hours at a time, currently this would be @ half load with my 400W PSU, I'm open to upgrading to a better PSU with a better inverter if necessary, since I can use an external battery it doesn't matter what state the battery of a second hand unit off ebay is in either.
 
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Soldato
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The impact of the power cuts is severe though so even if they don't happen often they are worth mitigating against, 3 days without having internet, telephones, or computers makes communication virtually impossible, I can't work or do my coursework, due to the power cuts I had to contact my uni to get an extension because I missed the submission date because I couldn't upload my coursework.

I've actually done the maths and my computer equipment is using approx 180W in low usage mode so a single £75 120Ah battery would last 8 hours ignoring inefficiencies. I don't know where you got the figure of thousands from?

If you only need less than 200w then yes that system would be overkill (was specced for a 750w system), but a new high efficient UPS (90%+) with 2 days worth of batteries could easily cost £2000 including multiple chargers for the batteries all mounted in a rack.

Assuming you're using the APC unit with 120Ah batteries with inefficiencies you're probably closer to 5 hours. In my spec it was based on 750w, so for 12 hours you'd still need 10 batteries which is £750 + chargers + racking doing it on the cheap so it would be cheaper with a 200w requirement.

If a substation has gone though, the chances of your net connection working is gone anyway so you'd be better off with a cheap low powered laptop and tethering for data if it's that essential, then run the UPS to the laptop to charge it. (highly inefficient but would last longer than the pc). Keep the UPS as it is for 5min power trips and run the laptop for extended downtime.
 
Soldato
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Personally, im not sure that in an emergency situation id need my whole machine powered up.

I would look for something that was low power i.e. a smartphone/tablet - and pair it with a heap of those portable power banks.

That way I could still check webpages, call people, access email and it wouldnt be as big and hungry as a full blown computer.

The reason im saying this is that in an emergency situation, it seems wasteful to have a powerful cpu, dedicated graphics cards, multiple storage drives and all that powered up when you just need chrome or whatever.

EDIT:

...so you'd be better off with a cheap low powered laptop and tethering for data if it's that essential, then run the UPS to the laptop to charge it...

yeah thats a good suggestion
 
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Caporegime
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I actually discovered that within 30 mins of the power going out that all mobile networks were emergency calls only, and by the morning there was no service at all, so satellite is the only way to get internet, phone and TV services in the case of a failed substation evidently. The only wireless service that I could get was FM radio.

I have a laptop which I've been using for leisure but it doesn't have the capabilities required to do the work I do and a dock to support triple monitors is nearly the price of two batteries anyway.

After thinking about it I'm kind of interested in beefing it up a bit anyway so it's capable of handling the lighting, mini-fridge and TV in my room.
 
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Permabanned
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You can't just leave generators outside in the garden, they aren't weatherproof. They're noisy and it has been pretty much impossible to buy petrol for the last couple of days

They are happy to sit outside and run all day in the rain, you just wouldn't leave them there all year. Noise can easily be mitigated.

With generators, storing petrol is part of the backup plan, for rural areas it's almost essential. You can get propane generators if you don't want to keep rotating petrol storage.

I guess it depends on how much redundancy you'd like, to me it is an add on, rather than one fix-all solution. Plus a generator is handy to charge up a UPS battery if required.
 
Man of Honour
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Personally, im not sure that in an emergency situation id need my whole machine powered up.

I would look for something that was low power i.e. a smartphone/tablet - and pair it with a heap of those portable power banks.

That way I could still check webpages, call people, access email and it wouldnt be as big and hungry as a full blown computer.

The reason im saying this is that in an emergency situation, it seems wasteful to have a powerful cpu, dedicated graphics cards, multiple storage drives and all that powered up when you just need chrome or whatever.

EDIT:



yeah thats a good suggestion

This is pretty much my solution - got a ~30 watt solar/generator setup, some leisure batteries (so can run low power mains stuff) and some USB battery packs and the latest acquisition a Toshiba Click 10 (plus some other stuff like USB rechargeable lighting).

Not really needed it yet, maybe won't ever, the floods here in 2013/14 prompted it as while it missed us only a few minutes up the road people were seriously affected by it - while its kind of a low priority in that kind of situation I do like having some tech capabilities if the mains goes down for any length of time.
 
Associate
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buy a deep cycle battery not a car battery, add an inverter and you're set. Add a small solar panel/morningstar charge controller and your computer is practically off grid.
 
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