Bl**dy UPS

[Johny B Good]

You think you were 'fooled'? I thought it was going to be an interesting post about UPS failure (Uninterruptable Power Supply)! Boy, was I disappointed!

[docholliday93]

So I wasn't the only one... (having just had a failure with a UPS which failed to resychronize after a tiny glitch on the mains - so the result was all the stuff running direct f rom raw mains was unaffected, but all the important tests that were 'protec ted' by the UPS were interrupted.)

[Davey]

I thought it was about Power Supplies too. That is a more likely subject matter in a d-i-y group than UPS/FedEx/Yell etc, I would have thought.

[Johny B Good]

Unfortunately, even the prudence of using a UPS, can't stop "Shit Happening"(tm) (usually due to surprisingly premature battery failure).

The next time I manage to get my hands on a suitable set of 4 x 12v SLAs 'at the right price' for the big SmartUPS2000 in my basement, I'm going to adjust the float charge voltage down from 13.8v per 12v battery to 13.5 volts (55.2v -> 54v).

I'm pretty well convinced that the higher voltage is far too excessive for SLAs to remain on float year in year out without suffering excess corrosion. The balance for extended life would seem to accept a higher risk of "Sulphation" with the lower voltage.

The clincher being the fact that a 12AH 12v battery I bought in a flea market a couple of years ago which showed a healthy 12.9v at the time on a borrowed DVM but in reality, when tested on a meter that didn't have a flat battery, was actually just over 12v successfully charged up from a couple of 1.2W solar panels over a month or so's period of intermittent afternoon summer sunshine kept its charge for the whole subsequent year despite often being used as a test supply for 12v gear ending up with a voltage of 12.76 volts before I placed it back on solar panel charging for a week or so's worth before the battery voltage crept up to 14v and I terminated the charging regime for this year a few weeks ago (currently showing 12.86 volts).

Clearly, the risk of sulphation would appear to be rather overstated going by that experience. All of which reminds me that I should check the single 7AH 12v SLA in the Backups500 next time I update the N4F image [showing, as of a few seconds ago: System uptime 186 day(s) 4 hour(s) 13 minute(s) 46 second(s)]. A quick calculation reveals that's an up time in excess of 6 months (just over 26 1/2 weeks). :-)

[tony sayer]

In article , Johny B Good scribeth thus

Well FWIW we've used SLA batt's for years in other locations and we've float charged them at 13.8 and they've been fine.

However do the APC ones really just use 13.8 and nothing higher??....

[Bob Eager]

I run the battery test weekly on all of mine. But the test script then waits 5 minutes and reads out how far the battery has 'recovered'. If the battery is on its way out, that will be a low value and flags the battery as on its way out...

[djc]

+1

Though I also rather like Amazon Locker, 1 mile down the road at their Holborn office.

[Scion]

Bill put finger to keyboard:

Before 9am delivery?

[Bill]

In message , Scion writes in response to:

Maybe, and I agree about DPD being good.

The Yodel experience so far:

Day1 Found note through door. Spent some time on their mediocre internet site, so had to ring their machine system. From this I discovered that the depot was 25 miles away on an industrial estate with a mumbled Welsh name, so didn't arrange to collect.

Day2. Son said they always come at about 11.30, so I rearranged my morning to be able to be there from 11.15 on. Arrived to find note that they had been at 10.44.

Day 3 (today). House sat from 09.30. Van arrived about 10 50 with 3 parcels, 2 of which had broken seals and outside damage. Brought to attention of driver, who said the only alternatives on his electronic device were to accept and sign or refuse to accept and sign. Made executive decision to accept. Driver said that they will have been damaged because they had been loaded on and off at the depot 3 times.

Rang son, who suggested I open one fully. Opened it to find it was network patch cables from eBuyer packed with a lot of coupons for Sainsbury's etc. Weird but OK..

Tidied up and went to the car. On the path were a couple of the coupons that had fallen out of the damaged package.

Even if everything is there when he checks tonight, I'll nag my son to complain to eBuyer.

[Simon Finnigan]

Regardless of what the driver said to me, I've written "box opened" and then signed. He went ballistic when he realised, but the parcels were in my house so there wasn't much he could do :-)

[alan_m]

One company (I can't remember which) has local agents who get the delivery if you are out. The local agent then delivers at 7 to 9pm or weekends.

[alan_m]

Parcel farce seem to have well thought out system. If you are working and out during the day they will leave it with a (not so) local sub-post office which have opening times of 9am to 5pm (or shorter).

I once went to a Business Posts depot to collect a parcel and got the distinct impression that the person looking for my package couldn't read and was attempting to pattern match the address on the card posted through my letter box and the address on the package.

In the same depot I also watched the delivery drivers returning from their rounds and unloading the un-delivered packages by just pushing them out of the back of the van and letting them fall on the depot concrete floor.

[Dave Plowman (News)]

Yes. Or with RM the local sorting office. So the only time many can collect is a Saturday morning - when the queue can be enormous.

I'd have thought a sorting office would run 24/7, so why not have it open a couple of evenings a week for collections? Now that it is privately owned and we were told that would provide a better service? But instead it seems the late collection from boxes is to be scrapped. Which can only lead to a poorer service.

Perhaps I've been lucky, but never had anything damaged in transit. Did have a computer stolen when sent by Parcel Force, and although insured took a great deal of effort to get compensation. So I've never used them since.

[Andy Burns]

The village sorting office closed years ago, now I hear the nearest town one will be closing, so it'll be a trip to one office for the whole city ... sounds marvellous!

[Johny B Good]

That seems to be the case with the three different APC units I've had experience with (SmartUPS2000, SmartUPS700 and BackUPS500).

Sorry for the delayed response but I was hoping someone with more extensive experience would chip in and continue this thread in its more usefullly topic drifted direction. :-)

My experience rather suggests that I won't be any worse off using a slightly lower float charging voltage than the 'Percieved Wisdumb" of the 13.8v figure.

I'm not bothered by the reduced effective run time (90% versus 100%?) provided this gives me a 5 years or more service life compared to a mere 3 years or so that seems so typical when the 13.8v value is chosen.

[Adrian]

In message , "Dave Plowman (News)" writes

I think some do. I'm sure I've picked stuff up at ~1900. OK not late evening opening, but a bit more than 9-5.

Adrian

[D.M.Chapman]

If not, just use Hermes - they safely store your parcel on the roof...

Darren

[Dave Plowman (News)]

The one here in fairly central London is mornings only, 6 days a week. ISTR it being opened one evening close to Xmas.

[Dave Liquorice]

Let me know as well I have a similar UPS but no batteries. 12 V 17 AHr IIRC.

I've just done similar to a SMartUPS 700, aftetr the last set of batteries went into serious meltdown, as in nasty smell and chared plastic...

Got the data sheet for the new batteries and did the maths using the recomend float voltage and derating by temperature. The UPS used to run decidely hot, it's now cool. Also added a fan in the space that would have taken the SNMP card.

I think it's the excess heat that really does for 'em.

[Johny B Good]

That would certainly be a factor in UPSes with integrated battery packs (the SmarUPS700 dissipates 20 watt with a fully charged or disconnected battery) but not for the larger units like the SmartUPS2000 which use a seperate battery pack case where its 35 watts or so maintenance losses can't directly pollute the battery environment.

Iin my case, the UPS didn't come supplied with the clip on battery case so the battery pack is mounted external to the UPS itself, subjected to the basement temperature which, during this summer's heatwave, peaked at a mere 19 deg C a week or so back.

It's currently hovering a degree or two above the minimum of 16 deg it registered during the past couple of weeks since I reset the markers during the "Heatwave" (in the winter, the temperatures seem to range between an 8 or 9 degree minimum and a 15 degree maximum).

Unfortunately, the problem of cell voltage balancing is magnified by stringing two or more 12v SLAs together to make up the required voltage for the higher powered UPSes (36v for an ancient Upsonic UPS600 I no longer use, 24v for the SmartUPS700 ditto, and an Emerson

450 I still use and the 48 volt's worth on the SmartUPS2000 currently awaiting a new battery pack - originally specced as 17AH SLAs, btw).

The Backups500 (500VA/350W) is the only one that uses just a single

12v 7AH SLA. This is riding shotgun on the mains feed to the NAS box which I was thinking of upgrading the OS on this Sunday which would have been an ideal opportunity to allow me to leave it shutdown during the inevitable reboot to let me take the UPS out of service to check its battery (and perhaps adjust the charging voltage).

I really aught to fit 'shunt voltage regulator modules' across each of the 4 SLAs used by the SmartUPS2000, set at 13.8v after I've adjusted the voltage per battery to 13.5v so that the good batteries in the string are protected against any battery that develops a higher leakage which imbalances the voltage distribution.

Such 'electronic zenner diode modules' would include a current limiting circuit driving a small incandescent 40mA 6v lamp which will give me an early warning of excess leakage current (the module across the failing battery being the one that shows the dimmest or absence of lamp glow).

A modest amount of shunt current to protect the good batteries in the string against a battery that would otherwise impose an excess charging voltage on its innocent siblings should significantly extending the life of the whole pack as well as allow me to identify the 'antisocial' battery intent on destroying its siblings.

In this case, the 2.7 watts due to a 50mA shunt current balancing circuit is a small power cost to pay out of the 35 watts or so normally consumed with a perfectly balanced set of low leakage batteries.

Ideally, of course, each of the 24 cells in the battery string should have their own shunt current module set for 2.3v each but this would only be practical with a string made up of individual cells rather than 4 pre-assembled 12v batteries.

The hope, in the case of a single 13.8v module per 6 cell's worth of battery is that the 6 cells in each battery will be pretty close to identical in capacity and follow a very similar aging process, remaining in balance much better than you could hope for between different 12v batteries even when they've been made on the same production line on the same day. let alone batteries that might well have been be sourced from different production lines or factories or manufacturers.

Trying to keep a battery balanced 6 cell's worth at a time might not be ideal but I'm sure it'll be a vast improvement on the current lottery scheme employed by APC.