Ups Battery Question

[jaideeguy]

My UPS [uninterupted power supply] eats batteries like 'lays potato chips' in that they constantly need replacement. It does have a fairly heavy demand in that it backs up my PC, router, and other little things.

I was wondering if I could replace the small capacity original battery with a larger external one.....like maybe a larger motorcycle battery and have the battery outside the original case for easier replacement??

all a UPS does is trickle charge the main battery, then invert it from DC to AC, right??

[thaimite]

Assuming the charging circuit limits its own current (probable) I see no reason not to install a larger battery or even have an extra battery connected in parallel outside of the case.

It should give a longer backup time, and the only downside I see is that it will take longer to recharge the batteries when the mains returns, which should not be a b dealig

Edited December 9, 2011 by thaimite

[InterestedObserver]

What guidance does the instruction manual give you regarding additional batteries?

[thaimite]

What guidance does the instruction manual give you regarding additional batteries?

I would very much doubt of the instruction book even mentions the subject.

If it did it would definitely air on the side of caution and not mention anything that would involve opening the case or making modifications.

The advice I gave above is based on my understanding of the electronics commonly used in these units, but of course it is up to the OP to make up his own mind and bear the cost of learning should any damage be done.

NOTE Adding extra batteries will not increase the ability of the unit to provide a higher wattage (VA) output as this is down to the electronics of the inverter.

i.e. You should be able to power the same load for a longer period, but not power a bigger load.

[InterestedObserver]

My UPS [uninterupted power supply] eats batteries like 'lays potato chips' in that they constantly need replacement.

I read this as a fundamental misapplication.

[jaideeguy]

My UPS [uninterupted power supply] eats batteries like 'lays potato chips' in that they constantly need replacement.

I read this as a fundamental misapplication.

What??

It's a 300 watt UPS and it mostly supports my pc and router and now it shuts down immediately when the power goes off....meaning that the battery is dead, right?

How many watts does a pc and 20inch lcd screen use??

[ludditeman]

More than 300W, you are overloading your UPS which is why the battery is failing.

PC uses 200-500W (look at the PC PSU rating)

TV uses 50-300W (look at the rating on the back of the Tv)

I just plug my PC into the UPS, everything else is straight in the mains, battery lasts 2-3 years or longer.

[InterestedObserver]

My UPS [uninterupted power supply] eats batteries like 'lays potato chips' in that they constantly need replacement.

I read this as a fundamental misapplication.

What??

It's a 300 watt UPS and it mostly supports my pc and router and now it shuts down immediately when the power goes off....meaning that the battery is dead, right?

How many watts does a pc and 20inch lcd screen use??

How often does the power go out and for how long, does the UPS have time to fully recharge between outages? If it's overloaded the UPS will shutdown.

Edited December 9, 2011 by InterestedObserver

[BangkokImages]

My UPS [uninterupted power supply] eats batteries like 'lays potato chips' in that they constantly need replacement.

I read this as a fundamental misapplication.

What??

It's a 300 watt UPS and it mostly supports my pc and router and now it shuts down immediately when the power goes off....meaning that the battery is dead, right?

How many watts does a pc and 20inch lcd screen use??

Yes, if your PC, router, and LCD are "average" you are severely overloading your UPS and I doubt it will provide protection when you most need it.

To be sure, go to APC's load configurator here and plug in your equipment.

[Crossy]

It's a 300 watt UPS and it mostly supports my pc and router and now it shuts down immediately when the power goes off....meaning that the battery is dead, right?

How many watts does a pc and 20inch lcd screen use??

As others have noted you're pretty near the line on your UPS capacity. Use a lamp as a load with the computer etc off, if the unit shuts down quickly or immediately, yes your batteries are shot.

New batteries are easy to obtain and not difficult to fit but I suspect you'll run into the same issues in future. Buy a bigger UPS.

There are a number of sites that talk about using external batteries, try a Google. Your big issue will be the UPS's ability to re-charge them in a reasonable time, sticking to something about double the capacity of the existing batteries should be no problem.

The other problem is that the UPS was designed down to a price and may well overheat when running longer than the designed run time, you could need to add a fan to keep things cool.

[seedy]

Another way to go is to power the computer and moniter with an inverter. Do not think a pure sine wave is required, modified sine wave should be sufficient.

Use any size battery bank you like.

When power restored, recharge battery - any charger will work.

May be cheaper - have not priced in LOS yet

[Crossy]

Another way to go is to power the computer and moniter with an inverter. Do not think a pure sine wave is required, modified sine wave should be sufficient.

Use any size battery bank you like.

When power restored, recharge battery - any charger will work.

May be cheaper - have not priced in LOS yet

I think you'll find that using a separate inverter and charger along with the associated fast changeover arrangements will be significantly more expensive than a purpose built UPS.

You can get UPSs with external batteries, I have one, 2kVA for 4500 Baht (no batteries) charges at 15A when on mains, add battery capacity as required.

[ludditeman]

You can get UPSs with external batteries, I have one, 2kVA for 4500 Baht (no batteries) charges at 15A when on mains, add battery capacity as required.

Do you have a web link for that device?

[Crossy]

Do you have a web link for that device?

Sadly no, mine came from Zeer Rangsit, pictures here (post#23)

[bdenner]

I've had a small car battery CS SN40 (32B20R) paralleled to the internal gel cell for two years now. At max load my hardware draws 270 watts and this combination keeps it alive for up to 40 minutes where with the gel cell alone I was looking at 10 mins max. Only problem, I think the UPS is overcharging the battery as I have to top up the acid with demineralised water every 3 months or so but they are still holding up strong and never let me down.

Edited December 11, 2011 by bdenner

[Crossy]

Only problem, I think the UPS is overcharging the battery as I have to top up the acid with demineralised water every 3 months or so but they are still holding up strong and never let me down.

The charging requirements for wet cell (car) batteries and gel cell batteries are different so you may well be overcharging the car battery. That said, if you're only topping it up every 3 months or so I wouldn't worry.

[Gary A]

Another option is to buy another small unit. Use one for the computer and the other for the router and monitor. The battery in my smallest UPS lasted six years. The other still has the original.

[astral]

I doubt that you pc ups will be able to cope with an external battery.

As crossy mentioned, it is the charging that will be the problem

Here is my setup

I use it to handle my TV, sat box etc, when the power goes off.

The battery is 200Ah and lasts about 2 years in UPS mode

That means the battery is in use all the time, being charged to keep it up,

that is why the small charger is there as well.

Currently I am using it in APS mode, this means that normally the mains provides the power and switches to UPS when the mains fails.

Hopefully this will give me longer battery life.

This setup is OK with some equipment but my Dreambox does tend to hang after the switch over.

The TV, WDHDTV box and HD satellite receiver all handle the swithover with aplomb.

With the big battery I do have about 4 hours of UPS power.

Note the additional cooling fan, mentioned by Crossy.

[BKKdreaming]

How many amp-hours is the standard battery ?

I assume they are all gel cell ,

I have seen some portable "workshops" use a UPS to test elevtric tools , etc when there was no mains power around

BK

[InterestedObserver]

How many amp-hours is the standard battery ?

I assume they are all gel cell ,

I have seen some portable "workshops" use a UPS to test elevtric tools , etc when there was no mains power around

BK

There is no "standard" amp-hour rating. It all depends on your needs and the ability of the UPS to keep them fully charged. I'd say most UPS batteries are lead-acid (AGM VRLA) maintenance free as opposed to a gel cell type construction.

Edited December 12, 2011 by InterestedObserver

[astral]

The standard battery in a computer ups is 7Ah

Capable of about 10 minutes life at 400w load

[Gary A]

Apparently there is much more to it than adding an extra battery to your exiting unit. I say that because I tried to order an APC 1500VA unit with an add on battery pack. The extra add on battery costs nearly as much as the UPS itself while just an extra battery was not that expensive.

ADDED - The APC and extra battery pack was not available at the time I ordered it.

Edited December 13, 2011 by Gary A

[Naam]

got three identical setups, each two 12V / @ 160Ah batteries, inverter with integrated (electronically regulated) charger and cooling fan, input 24V / output 230V - max capacity 2000VA. each system on dedicated circuit.

1. powering water supply house.

2. study of Mrs Naam, PC, printer, scanner, TV, 2 SAT-receivers, 2 harddrive recorders, DVD, stereo, lights.

3. my study 2 PCs, 3 screens, three routers. TV-room, plus see above.

longest power cut bridged 9 hours without any problems, age of batteries 3 years and 4 months.

cost:

inverter (imported) 8,000 Baht

each battery 3,700 Baht

[seedy]

Naam - I am curious.

Did you get a pure sine wave inverter, or does your equipment happily handle input from a modified sine wave ??

Thanks.

[Naam]

Did you get a pure sine wave inverter, or does your equipment happily handle input from a modified sine wave ??

to tell you the truth... i have no idea. the sine wave question popped up in various threads (inverters / transformers) and although i'm a technical man i don't understand and never really bothered to understand it.

what i can tell you is that i never had a problem with any of my electronic equipment.

[BangkokImages]

Naam - I am curious.

Did you get a pure sine wave inverter, or does your equipment happily handle input from a modified sine wave ??

Thanks.

Knowing which power supplies 'must have' a pure sine wave output for optimal operation is technical in nature and involves understanding which power supply you have in your equipment and why your equipment needs that type of supply. So basically beyond the scope of most consumers.

You can cheat by letting UPS manufacturers do the work for you, but I wouldn't count on this 100%. APC will tell you what types of equipment are recommended to be used with their UPS devices and which ones, and they'll further list which of their UPS devices output a pure sine wave vs. a manufactured (square) sine wave. If they say computers are recommended for the cheaper (consumer class) for use, then you're probably good to go. But don't think you can just plug anything into the UPS and have it work right.

A couple things I know for sure should NOT be used with anything other than a pure sine wave would be studio strobes and high-end audio equipment. You can ruin both in short order using anything but a pure sine wave. I'm sure there's a lot more.

Sometimes you can buy combination pure sine wave inverters and gel cell batteries to run them and charging circuits for a reasonable price. A favorite of mine is Paul Buff's Vagabond II which is being discontinued and you can get them discounted here. (scroll down) Their new models are great too, but they're integral and it's hard to mix/match batteries for more capacity. The Vagabond II is a high quality unit. In the bag you get a gel cell, a pure sine wave inverter, strapping, and an international charger. I've used these for years and the inverters are first class. The gel's I replace ever 3-4 years depending on usage.

[Naam]

A couple things I know for sure should NOT be used with anything other than a pure sine wave would be studio strobes and high-end audio equipment. You can ruin both in short order using anything but a pure sine wave. I'm sure there's a lot more.

can you give us some details / explanation "why"? thanks!

[BangkokImages]

A couple things I know for sure should NOT be used with anything other than a pure sine wave would be studio strobes and high-end audio equipment. You can ruin both in short order using anything but a pure sine wave. I'm sure there's a lot more.

can you give us some details / explanation "why"? thanks!

In very vague terms.. this is heavy theory and anyone can google it if they're interested.

Mostly, the more sophisticated an electronic device becomes, the more it requires true sine wave power. It becomes critical for timing, for keeping RF noise at bay (less) so any type of transmitting device (CB and ham radios, signal amplifiers) and the such, efficiency of a device, anything that controls motor speed, many of the adapters you use to charge your batteries/phones/computers..

All power supplies have fault tolerances built in so they are in fact designed to operate plus/minus from their ideal specifications, but without knowing these tolerances (they're listed in the specs of most equipment, but can vary from the specs depending on age and how much abuse the item has incurred) and exactly what type of power the inverter is outputting.. you're more or less guessing if all will be okay.

I would say if you're running a modern desktop computer on a modified sine wave UPS/inverter device you'll be okay. But when you start plugging in monitors, printers (especially high draw items like lasers and finicky printers like ink jets), adapter devices, etc.. you are risking that gear and would probably be better off with a quality surge protector device that doesn't modify the natural sine wave coming from your wall socket.. than a UPS device. Counter intuitive I know, but true nonetheless. Keep in mind that most surge protectors merely use MOV's (metal oxide varisters) with long reaction times to protect your gear.. which basically means it will keep your equip from catching fire, but not from taking a spike and hurting your equipment.

Power, power supplies, and so forth.. is more complex than most think. But if you go with the UPS manufacturers recommendations you'll probably be doing okay. Read the fine print, most won't recommend laser printers, CRT monitors (not an issue anymore), televisions, and many items we regularly plug into them.. We think a UPS has to be better than what comes from the wall, after all it's a UPS.. but when you realize that most consumer class UPS devices are providing modified sine waves.. then what comes out of the wall is better for many devices/equipment than what comes out of the UPS.. better if you surge protect it.

This is why I started out pushing server class UPS devices which output pure sine waves. It takes a lot of explanation to show the real value in this choice.

[thaimite]

Whilst the above theory is correct and true sine waves may be needed for some equipment such as audio amplifiers etc where high frequency electonic noise would cause a problem, I would dispute the need for true sine wave converters with current computer equipment especially PC's, LCD monitors printers and modem/routers.

My reasoning behind this is simple.

Almost all (if not all) of these devices are usually fitted with a Switched Mode Power Supply

A switched mode power supply is used to obtain the various internal DC voltages needed by the device.

This is done by chopping up the nice expensive sine wave and feeding it in to its own regulator circuit which supplies the necessary output voltages.

The operation of switched mode power supplies is too complex to go in to here, but an good understanding of the concept can be had by reading the above link.

Switch mode power supplies are used because they are smaller, cheaper and lighter than regular transformers

.

As a simple rule of thumb, I would suggest that if the device you wish to power is very heavy because it has a big transformer inside, then consider a true sine wave UPS, however in most cases using any PC equipment this is not required.

As far as using the AC signal for timing, I am unable to think of any electronic equipment where that would be the case. Motors run at a speed proportional to the mains frequency which is why US 60Hz equipment should not be used in Thailand or the UK which is 50Hz, but I suspect most people in this forum will not be running motors on their UPS(Disk drive motors do not apply here)

Edited December 14, 2011 by thaimite

[BangkokImages]

Whilst the above theory is correct and true sine waves may be needed for some equipment such as audio amplifiers etc where high frequency electonic noise would cause a problem, I would dispute the need for true sine wave converters with current computer equipment especially PC's, LCD monitors printers and modem/routers.

My reasoning behind this is simple.

Almost all (if not all) of these devices are usually fitted with a Switched Mode Power Supply

A switched mode power supply is used to obtain the various internal DC voltages needed by the device.

This is done by chopping up the nice expensive sine wave and feeding it in to its own regulator circuit which supplies the necessary output voltages.

The operation of switched mode power supplies is too complex to go in to here, but an good understanding of the concept can be had by reading the above link.

Switch mode power supplies are used because they are smaller, cheaper and lighter than regular transformers

.

As a simple rule of thumb, I would suggest that if the device you wish to power is very heavy because it has a big transformer inside, then consider a true sine wave UPS, however in most cases using any PC equipment this is not required.

As far as using the AC signal for timing, I am unable to think of any electronic equipment where that would be the case. Motors run at a speed proportional to the mains frequency which is why US 60Hz equipment should not be used in Thailand or the UK which is 50Hz, but I suspect most people in this forum will not be running motors on their UPS(Disk drive motors do not apply here)

a. LCD monitors, printers, and modem/routers often run off simple adapters which are not switched mode power supplies. Besides, trusting the quality (generally crappy on consumer level electronics) of switched mode power supplies is problematic at best.

b. None of this is simple, trying to make it so requires generalizing and I wouldn't recommend generalizing when it come to protecting expensive equipment.

c. To most consumers ANY UPS device will appear very heavy as they contain heavy gel cells and more. Don't assume a pure sine wave from any UPS, instead confirm a true sine wave listed in the specifications. A true sign wave UPS is an important feature, it will be listed if it is one. Omission of this specification should raise a flag.

d. When you understand how the electronics work many electronic items will come to mind when it comes to timing. This reference might be helpful. Or scroll down here to where it says "Do I need a pure sine wave", another source, even Ehow lists the same examples of timing devices and which equipment you might want to avoid on anything other than a pure sine wave inverter.

It isn't my wish to argue this or debate theory, but more to encourage those without the electronics background to follow the UPS manufacturers recommendations on what should be powered by their specific UPS devices and even to be skeptical if they see something listed which might be a mistake. It's important to keep in mind that UPS's come in several flavors, modified sine waves and pure sine waves, so don't lump them all together.