Opening a UPS

lsheed_cn said:
If your battery has been drained and not recharged its probably toast, replace it with another one of the same physical size / rating / type. Last I looked its about R70-150 for a battery, depending who you buy from.
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hmmm...seems like it. Will take it out and check with a multimeter exactly how dead it is.

Any ideas how to get rid of the old battery? Can't exactly chuck it in a dustbin seeing how its lead/acid. Do you think the PnP battery recycling will take it?
 
HavocXphere said:
Any ideas how to get rid of the old battery? Can't exactly chuck it in a dustbin seeing how its lead/acid. Do you think the PnP battery recycling will take it?
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Usually put my discards out separately for the dustmen to take care of (I believe they get scrap value from the recyclers).

BTW my last batch of UPS 12V 7.2AH batteries were R175 excl from Mantech this week, don't know if they anticipated the demand created by load shedding.
 
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MickZA said:
Usually put my discards out separately for the dustmen to take of (I believe they get scrap value from the recyclers).
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Thats one option - I'd prefer giving it straight to a recycler though. Don't care about scrap value...just want it safely disposed of.

MickZA said:
BTW my last batch of UPS 12V 7.2AH batteries were R175 excl from Mantech this week, don't know if they anticipated the demand created by load shedding.
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I should be OK on sourcing a battery...I know some people in that direction.

Just checked UPS pricing...fml when did they become so expensive?
 
I did my calculation incorrectly

So if its a 12v7A battery @ 84W / 0.6 (power factor) = 140VA (not 50va)
Its still completely bogus though, when they say its 600VA.

My thoughts are that they spec them for a run time of 15 minutes in incredibly small print somewhere (which is still incorrect calculation wise, but way way closer to the lies that they publish).
 
MickZA said:
BTW my last batch of UPS 12V 7.2AH batteries were R175 excl from Mantech this week, don't know if they anticipated the demand created by load shedding.
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Good grief. Last battery was less than R100 incld. I recall the courier was almost as much as the battery price.
 
RoMark said:
Good grief. Last battery was less than R100 incld. I recall the courier was almost as much as the battery price.
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Prices have shot up since February when I was paying R140 excl, should be noted that I ordered the last batch on Thursday after the load shedding though.
 
lsheed_cn said:
My thoughts are that they spec them for a run time of 15 minutes in incredibly small print somewhere (which is still incorrect calculation wise, but way way closer to the lies that they publish).
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Yip - the consumer level stuff seems aimed squarely at "shut down PC safely".
 
I may just put one phase on battery backup, but only if it gets worse.

A 3500KW bidirectional battery inverter is about 50k though (eg Victron Quattro), and I still need batteries on top, plus an ATS switch. To do it properly I need 3 inverters... Its not cheap...
My entire system was about 90k-115k rands odd for 30 x300w panels + 10KW inverter + mounting and cabling (shipping was a bit contentious)

There's a solar show end of the month in Shanghai though, have a friend going so told him to take a look out for me for AC coupled inverter chargers. Cheaper for me to import usually, than buy locally.
 
lsheed_cn said:
I may just put one phase on battery backup, but only if it gets worse.
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Thats pretty much guaranteed. Check the summer/winter graphs here: (Awesome info link by bruce btw)

bruce_the_loon said:
Go have a look at the presentation at the press conference yesterday, especially the photos of the coal yards and conveyers from page 10 onwards. Puts the issues into some perspective. http://www.eskom.co.za/OurCompany/MediaRoom/Documents/poweremergency6march.pdf
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What gets me is that the IPP applications were oversubscribed by 400%

If they said ok to all of those, we'd have that 4000MW of power that Medupi and Kusile are supposed to produce "any time soon now(tm)" sooner than Eskom could have that running.

Currently though, its paperwork galore for implementing stuff, and limited amount of power available to bid for projectwise.

We really need to be pushing toward solar, wind, and other renewables to get generating capacity upwards, and rather spending Eskom's money on *storage* technologies so that we can use that generated power at other times.

This is the sort of stuff thats interesting - http://www.lightsail.com/
 
lsheed_cn said:
What gets me is that the IPP applications were oversubscribed by 400%

If they said ok to all of those, we'd have that 4000MW of power that Medupi and Kusile are supposed to produce "any time soon now(tm)" sooner than Eskom could have that running.

Currently though, its paperwork galore for implementing stuff, and limited amount of power available to bid for projectwise.

We really need to be pushing toward solar, wind, and other renewables to get generating capacity upwards, and rather spending Eskom's money on *storage* technologies so that we can use that generated power at other times.

This is the sort of stuff thats interesting - http://www.lightsail.com/
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100kW scale?

Storing it would be good but the solutions tend to either be inefficient (pumped storage) or too small to make a dent (like above).
 
lsheed_cn said:
100+ KW scale - http://www.ambri.com/technology/

http://www.ambri.com/storage/documents/2014-Brochure-v3.pdf

Solutions are definitely out there..

I'm keen on Flywheel based stuff eg Velkess, but there isn't really anything available quite yet for the market segment i'm looking for (home use).
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Its not even close to big enough. For comparison:

Ingula pumped storage - 1 333 200 kW
Ambri batteries - 500 kw

As I said, too small to make a dent even if you buy many of those container sized batteries. Its cool tech certainly (same for flywheels), but I don't see it working on national grid scale.
 
40-foot shipping container rated at 500 kW and 2MWh storage capacity
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2MW storage for a 40 footer. 100 of those is 200MW, thats enough for a small power station, and size wise, is way smaller.
Pumped storage is good when you have the water, and the space to do it. The Ambri stuff is game changing (assuming its real).
 
lsheed_cn said:
2MW storage for a 40 footer. 100 of those is 200MW, thats enough for a small power station, and size wise, is way smaller.
Pumped storage is good when you have the water, and the space to do it. The Ambri stuff is game changing (assuming its real).
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Pretty sure you're reading it wrong. The 500kw is the number you should be looking at, not the 2mWh. So you'd actually need 400 of them to get to (tiny) power station status. You'd need 8000 40ft containers to cover the shortfall we had on on Thursday. You're better off trying to cover it via pumped storage.

Even if you did go for the 8 000 container option...I doubt a small startup could build them fast enough or that it would make sense financially. Plus you need to recycle 8 000 containers worth of chemicals at the end.

Its interesting tech for sure, but it won't help here imo.
 
lsheed_cn said:
I did my calculation incorrectly

So if its a 12v7A battery @ 84W / 0.6 (power factor) = 140VA (not 50va)
Its still completely bogus though, when they say its 600VA.

My thoughts are that they spec them for a run time of 15 minutes in incredibly small print somewhere (which is still incorrect calculation wise, but way way closer to the lies that they publish).
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Your calculations are most certainly not correct. You are confusing amps (A) with amp hours (Ah).

A 600VA ups can supply a maxiumum of 600VA (600W at unity power factor). At full load a 13.8v 7Ah battery would last 10 minutes roughly.
 
If you use 13.8v @ 7A = 96.6W / hr capacity battery.
600W at a power factor of 1 would drain that in 10 min as you state. (Well actually 579,6W draw [96.6W = 60Min, 579.6 = 10min])

And thats assuming 100% efficiency. And the battery would be toast. You don't want to drain a lead acid battery > 50% in order to prolong lifetime. So you can actually half that to get usable storage capacity without damaging the battery.

So, I'm sorry, ratings are still complete garbage.
 
lsheed_cn said:
If you use 13.8v @ 7A = 96.6W / hr capacity battery.
600W at a power factor of 1 would drain that in 10 min as you state. (Well actually 579,6W draw [96.6W = 60Min, 579.6 = 10min])

And thats assuming 100% efficiency. And the battery would be toast. You don't want to drain a lead acid battery > 50% in order to prolong lifetime. So you can actually half that to get usable storage capacity without damaging the battery.

So, I'm sorry, ratings are still complete garbage.
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The rating isn't garbage. It tells you one part of the story. If you're too thick/inexperienced to ask for the full story, but instead rely on old wives tales and rule of thumb criteria, they I guess it sucks to be you.

UPS ratings are quite thorough. You can easily find the efficiency (most are over 90%), the W rating and the VA rating, the overload tolerance, and the battery size. It's easy to chose a product that suits you.

ElecEng, you're wrong about the capacity. VRLA batteries come with datasheets because the Ah rating is normally at a 20 hour discharge rate (sometimes 10 hours). The Ah rating at 1h is significantly less. For example, the Panasonic battery in my photo is rated at 433W for 3 minutes (down to 9.6V, which is perfectly fine for such a high current), or 1.8Ah.
 
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