Hi,
Normally, the UPS battery life should not be less than 5 years if there is no power surge or spike. But Ups batteries are need to be replaced within 2 years. Does that mean that the sudden power surge or cut, may have an impact on this device. The main part of the ups is its battery and would some one explain why this is happening? My APC ups, lasted for more than 5 years and on replacement of battery, lasted another 2 years. What are the reasons for electric attack on this electronic device.

 

Welcome to AAC!

Battery life should be a function of initial quality, how frequently they were used, how low voltage was allowed to drop, and how they were charged.

 

Here's what I know about sealed lead acid batteries (SLA Batteries): They prefer a particular voltage. If that voltage is exceeded they heat. When they heat they dry out. OR if they are not maintained at that particular voltage they can sulfate, meaning the plates of the battery begin to clog up with sulfides, thus, reducing their ability to deliver a charge. Not to mention that their charge is already somewhat diminished because of being under charged.

I'm assuming yours is a 12 volt battery. Properly maintained voltage on this battery should be 13.6 to 13.8 volts. Any higher and there is the possibility of drying out the battery. During a power failure the battery becomes drained (to some extent - depending on how long and how heavy the load). When power is restored the battery voltage SHOULD go up into the low to mid 14 volt range for a short while. But it should settle back down around 13.8 volts. If the battery is not charged that high initially then sulfides can build up. The higher voltage is needed to clear the sulfides. But if the battery is not being maintained at least 13.6 volts then the battery state of charge is adversely affected, leaving it at less than 100% capacity. When an SLA battery (any lead acid battery) is at 80% capacity (not voltage) it's considered dead.

Check the voltages when the battery has been on the charge for at least 24 hours. It should be 13.6 minimum. Disconnect the battery and check the voltage after the battery has had a chance to relax. The relaxed voltage should be 12.6 volts (100% capacity). If it's below 12.2 volts then it's suspected the battery may be old, weak or dying. Restore the system and then unplug the UPS while the computer is on. While all the usual components are being powered solely from the UPS. Let the UPS go through its programmed time limit, which is typically 30 minutes I believe. Not sure on that, and yours may vary. Restore power and check the battery voltage while the battery is charging. Voltage should go up to about 14.4 volts (or close to that). If these conditions are not being met then I'd consider replacing the UPS.

The normal way a UPS works is that power is supplied through the inverter via the DC voltage on the battery. The battery voltage is maintained during normal operation. When power fails the battery takes on the load. From what I understand about UPS's your computer is not running off of the main voltage but off the inverter in the UPS. So at all times the UPS is inverting and supplying power to your computer, modem, router, backup hard-drive, monitor and in some cases the printer too. On mine I have the computer (iMac) and the router/modem. Nothing else. And typically my batteries last around the 5 year mark. My UPS's seem to last around the 10 year mark. So if yours is old it may be time for a new(er) unit.

 

You can buy 10 or even 20 year VLRA batteries for industrial applications but it's cheaper to change them for non-critical applications.
http://www.battcon.com/papersfinal2006/giesspaper2006.pdf
http://www.staticpower.com/ups-systems.html

 

If the batteries are not properly float charged to maintain them (either too high or too low a float voltage), it can shorten their life.

 

UPS units seem to be hard on batteries. Maybe the cheaper ones don't have very good charger designs.
On one I had here, an old car battery was used to replace the SLA and that lasted for a few years.
I would like to have a large bank of nickel iron batteries as they have very long life. If you overcharge them and they boil dry, just top them up again. And if they go flat, just recharge them. I worked at a shortwave transmitter, Radio Australia, and there were some that were installed at the end of WW2. As far as I know, they are still there. these batteries have less capacity and higher self discharge, but hugely longer life. My plan, if I can get the $$$$ is to have a lot of these at home. As it is, I have 10KW of sola on the house, and a panel on the shed that runs a few things. These would be great batteries for a UPS as they would be kept fully charged, so self discharge would no be a problem. My UPS units have killed their SLA batteries and I'm still to get round to replacing them. Maybe with some of these?
I don't know as yet what the charging changes needed will be.
It could be an interesting project.
Has anyone else had any experience with these batteries?

 

Thanks very much for all the replies. Dendad had touched upon problem in self discharging and in a kind of fully charged.Tony has replied effectlvely thus.
The normal way a UPS works is that power is supplied through the inverter via the DC voltage on the battery. The battery voltage is maintained during normal operation. When power fails the battery takes on the load. From what I understand about UPS's your computer is not running off of the main voltage but off the inverter in the UPS. So at all times the UPS is inverting and supplying power to your computer, modem, router, backup hard-drive, monitor and in some cases the printer too. On mine I have the computer (iMac) and the router/modem. Nothing else.
I wish to point out, that only monitor and harddisk are connected with the numeric 600 ex v ups. There is provision for 3.
My subquery; My ups does not have a indicator to show, whether it is charging or not, but i could hear some specific sounds it makes. How to know, that after full charge, it stops charging? Is there any way? I only notice the failure ,when ups fails with power off at once.
UPS only supports for a maximum 3 to 5 minutes after the power failure, to close the computer. How to self charge then. Should i compulsorily power off and let the computer run for 5 minutes before switch on to enable self discharging.
The problem is if UPS fails, your system is affected by sudden closure of all the open programs and their handles, the files open stage etc.
1. Can i power on the UPS continuously for hours without break?
2. I think that battery occupies most place in ups costwise and size wise. The weight of the UPS is heavy because of the battery. some suggest only use power surge protector instead of ups. pLease say something on. I love your replies and i am gaining some intrinsic knowledge of a small thing, that could cause, major trouble if it is not working

 

Some UPS are connected to the computer via some sort of communication line. When power fails the computer is supposed to automatically save your work before power goes out. Back when UPS' were new and power went out the person at the computer had a few minutes to save files before power was completely lost.

As I said, I like having my computer, router and backup hard drive connected to the UPS. When working with my computer, if power goes out I have plenty of time to save files. Incidentally, the computer I'm working off of right now only has a surge protector. No UPS. Why not? Because this computer is more often used for hobby projects and casual surfing of the web whereas my other computer (the wife's computer) is on the UPS. She does her schoolwork on it. If power goes out she needs to be able to save her files BEFORE the computer shuts down.

 

About 40 years ago I was working for an "Emergency Lighting Service" company. They serviced lots of systems ranging from small SLA backup lighting systems all the way up to hospital generator systems. Many schools had huge banks of NiCad batteries. What I was amazed with was that when they went dry you could just fill them back up and they'd be good. Had 50 amp 1.2 volt cells that could be bolted together in any configuration. Series for voltage, parallel for amperage. MOST were set up as 32 volt systems, and I remember replacing many transformers that gave up before the batteries did. I even scrapped out many dozens of these systems for LA batteries. Was allowed to take scrapped batteries home - as long as I wasn't scrapping them. Used them on some projects. One project was a friend of mine wanted to set up a wind turbine and charge batteries. I gave him a whole bunch of these 50 amp NiCad's. Never seen such a happy man.

External batteries are probably not a good idea for a small UPS. I'm sure the UPS was designed with the idea of charging a 20 amp 12 volt battery. But to try and use a UPS to charge a 400 amp battery - I don't know how long the UPS would last. So I'd suggest again, if you're going through batteries it's probably time to replace the UPS.

 

Just a thought, I had one UPS that did not have mains isolation to the battery. DANGER!!!!
I don't know how common that is, but it is something to be aware of if you were to put an external battery on it. Don't on that type. Also make sure all is off and unplugged when doing anything with any UPS. They can be leathal.

There are a couple of versions of UPS units. Some power the load from the inverter all the time, but others feed the mains out and have a relay switching system that disconnects the mains when it fails and starts the inverter and switches to that. With the latter type, there will be a short glitch on changeover. Most systems can cope with that.

 

1. Can i power on the UPS continuously for hours without break?
2. I think that battery occupies most place in ups costwise and size wise.
3.My ups does not have a indicator to show, whether it is charging or not, but i could hear some specific sounds it makes. How to know, that after full charge, it stops charging? Is there any way?
No anwser for these three queries

 

1. Can i power on the UPS continuously for hours without break?

Do you mean run the UPS on the mains? If so, yes. They should be left turned on and running on the mains all the time. That is what they are for, to automatically run the supply when the mains fails.
If you mean run your load from the UPS when the mains fails, that depends on the UPS battery size, power rating and load.

2. I think that battery occupies most place in ups costwise and size wise.

The battery can be a large part of the size and the cost, but I have just replaced the batteries in a $1000 UPS with "non genuine" SLAs for $120.

3.My ups does not have a indicator to show, whether it is charging or not, but i could hear some specific sounds it makes. How to know, that after full charge, it stops charging? Is there any way?

It depends on the UPS. But battery management will be taken care of by the UPS itself. The one I have just gives an alarm if the battery is getting low. Some can be interrogated via USB, serial or even Ethernet for more info.

 

UPS is just another word for inverter. The reason why it's called an "Un-interruptable Power Supply" is because it supplies power when main power fails.

1) You don't need a UPS. You can hook up an inverter that is powered from a bank of car batteries (in parallel) if you want and power your equipment all day from the batteries - until the batteries drop below 80% capacity. So in theory you can run continuously as long as you have a 12 volt DC source. The "UPS" makes everything neatly packaged because it's just a battery charger and an inverter all packaged together.

2) It's likely the cost is greatly influenced by the battery. However, depending on the features your UPS has, cost can go up or down.

3) You shouldn't need any indicators as to whether it's charging or not. If you were to open it up, access the battery terminals and plug it in you should be able to see if the battery is charging by using a volt meter on the battery. Someone already cautioned you about how deadly a UPS can be - that admonition is absolutely accurate - you MUST be careful not to touch the wrong thing. Even with your probes. So don't attempt to check the circuit board unless you're 200% sure what you're doing. I know, I wanted to check voltage on something and blew a MOSFET right out of its package just by touching the wrong thing. So unless you're beyond absolutely sure you know what you're doing I'd advise you just leave the board alone.

Here's what to check for (ON THE BATTEY): With no load, with the UPS plugged in - battery voltage should be 13.6 volts (when fully charged). Leave the unit alone for a couple hours and let it finish charging the battery. If the battery voltage is sitting up around 14 volts then you're over charging the battery and THAT may be why batteries are lasting 2 years and not 5. OR if after hours the battery voltage is still below 13.6 volts, like 13.4 or lower then the battery is not being properly charged. Like I said many posts ago - it may be time for a new UPS.

Alternatives: You can set up a car battery with a battery charger set to keep the battery charged to 13.8 volts. Keep in mind batteries tend to expel acid - something I learned when I was a teen and powering a car radio from a car battery and a car battery charger sitting on the rug. Burned the rug with acid. Dad wasn't too happy about that. But keeping a battery charged and connected to an inverter, you can power a number of things from a cheap inverter you get at AutoZone or Walmart or wherever you prefer. But these inverters are inefficient. Good ones (expensive) may run at 80% efficiency, meaning you're not wasting too much of your battery making heat. Others are worse and can be 60% efficient or even worse.

ME? I'd just buy a new inverter if I suspect the old one is not doing its job. That'd be my advice. But if you wanted to go with an inverter and a battery and charger - that's up to you. Be sure you understand the dangers of acid burns to your clothing, furniture and a rug or two. Acid can also burn YOU. AND be sure you have good wiring. A car battery dead shorted can melt wires faster than you can blink. Melted wires are heat and can start fires. There can be consequences to trying my alternative route.

At present I have a car battery sitting on a shelf and constantly maintained at 13.6 volts in my garage. A car radio is hooked to it and will play even when there's a power failure. All made from junk I have laying around, so no cost to build - except my time and a little solder.

 

LA's need special care in bot use and charging. if the proper special care is there and the batt is quality, you can get ~10yr possibly 20yr lifespan. AGM LA's seem to be more common now over std wet batts. and batt temp plays a major role in lifespan.

"deep cycle" batts are a special LA. almost all UPS systems should be AGM or GEL deep cycle (if using LA).

smart chargers are not actually smart, but have charging programs that properly match the batt type. some have hi-freq modes in the charging cycle to handle sulfate issues.

the big diff between "UPS" and just a inverter+batts is, UPS's will have xfer switch, which is what you need for the "U" part of "UPS", etc.

 

the big diff between "UPS" and just a inverter+batts is, UPS's will have xfer switch, which is what you need for the "U" part of "UPS", etc.

True enough. However, by powering from an inverter independent of main power or not - there is no interruption, so no need for a transfer switch.

In the case of the UPS that HAS a transfer switch, the inverter part of the UPS is not running, not until main power is interrupted and the transfer switch kicks in and turns the inverter on to power your equipment. That is more efficient. But to constantly run an inverter from a battery, whether it's being charged or not, does not require any transfer. Either the battery is being charged or it isn't. However, the inverter is always running off the battery. Hence, no transfer required.

Note: I've heard that many inverters are not real good at powering some loads like AC motors. I don't have experience with them so I can only repeat what I've heard, so what I JUST said may be wrong. I'm sure someone will correct me if I'm wrong, but that's what I heard.

 

Note: I've heard that many inverters are not real good at powering some loads like AC motors. I don't have experience with them so I can only repeat what I've heard, so what I JUST said may be wrong. I'm sure someone will correct me if I'm wrong, but that's what I heard.

not wrong

depends on the type of inverter, modified sine wave (MSW) vs pure sine wave (PSW)

vacuumed the house using a 240v/1200w vacuum cleaner last week off the 3kw PSW ups, not a problem at all. had i tried it with the MSW, the motor would have been noisy and complaining big time

 

That's what I like about this website. Always learning something. So I'm just guessing here, but a UPS probably runs a PSW. Correct?

 

generally 2 types of UPS/Inverters
PSW - pure sine wave (expensive)
MSW - modified sine wave (cheap to expensive)
pure sine wave is very close to what you get out of the power point and generally more efficient than MSW
modified sine wave is 'dirtier' version of pure sine wave

if shopping for one or so, try to avoid buying modified sine wave

 

I'd say 3 major types:
3) Always on

Not all UPS units are generator compatible. The always on ones usually are.