My UPS stopped functioning. If the power goes out it beeps for a second and then everything dies. I figured it was the battery, so took it apart and removed the battery. I decided I'd test first. Without load the voltage across the terminals is 12.8. With a small load (12 V halogen bulb) it measures 11.4. Is that too much of a drop?

My UPS stopped functioning. If the power goes out it beeps for a second and then everything dies. I figured it was the battery, so took it apart and removed the battery. I decided I'd test first. Without load the voltage across the terminals is 12.8. With a small load (12 V halogen bulb) it measures 11.4. Is that too much of a drop?

How old is the UPS? Is it connected to your PC so you can manage it through software?

Leave the buld connected and see if it stays on for any lenght of time, if not the battery is dead or is not charging.

The battery should read about 13V when fully charged and should not drop much on load You do not state the wattage of the halogen lamp but I would be suspicious.

One other thing to check is the voltage of the battery when charging, That should be about 14V to ensure that the UPS charging circuit is OK

Be very careful I do not want you complaining about my advice on this forum after you have killed yourself.

On mine the battery failed and I was able to buy a similar 12V sealed Lead Acid battery for about 500Baht from a local shop. A slight modification to the mounting bracket was all that was needed to fit the higher capacity unit that has worked well for the last 10 months

The UPS is about four years old. Never had the battery replaced. It is not controlled through software. It's a cheap one with no data interface.

The halogen bulb is very low wattage. I can't read it anymore, but I think it's no more than 7 or 10. It's been burning brightly for about three hours now.

In other words, the battery seems OK. When I took it out of the unit it seemed full charged and read 12.8 volts without a load. I think this also means that the charging circuit is OK.

almost certainly the battery needs replacing, if it's 4 years old. the halogen bulb test notwithstanding. the batteries used in UPS devices are simply not designed to last very long. a very high quality battery might need replacing after 5 years. 3 years would be more typical. the ability to put out a small amount of current to light a bulb doesnt test the properties of the battery sufficiently. if you get a new battery this will almost certainly fix your problem.

Edited October 22, 200916 yr by somefellow

Remember that this is Thailand

Quality is not what you are used to in the West.

The battery in my Toyota gave up at 3.5 years of age.

In the US my batteries would last 5-6 years.

Buy a new battery.

Here's why I'm gun shy. I had a solar pump for my pond. It stopped working. I figured the battery was toast. I bought a new battery. It still didn't work. Turned out the problem was with the charging circuit. So, I wasted money on the battery. I don't want to make the same mistake again….

You say this UPS is a cheap one. You say you have had it 4 years now? A new battery will cost about 500 to 800 baht. Another cheap UPS will cost you about 1,500 to 2,000 baht.

Buy a new one if you think the problem is more than the battery. You had this one now at a cost of about 500 baht a year. If you're a smoker and drinker I bet you've spent in the cost of beer and smokes the price of a new UPS trying to decide what to do.

You say this UPS is a cheap one. You say you have had it 4 years now? A new battery will cost about 500 to 800 baht. Another cheap UPS will cost you about 1,500 to 2,000 baht.

Buy a new one if you think the problem is more than the battery. You had this one now at a cost of about 500 baht a year. If you're a smoker and drinker I bet you've spent in the cost of beer and smokes the price of a new UPS trying to decide what to do.

LOL! In fact, I already bought a new one. Getting this old one working was just sort of a project to fill some time and learn something.

Sometimes taking the time to learn and understand turns out to be more valuable than a quick fix.

I'm a fixed income retired geezer. Time is nothing.

You are lucky to get more than 2-3 years service on a sealed battery in these temperatures. Am sure you need a new battery.

You are lucky to get more than 2-3 years service on a sealed battery in these temperatures. Am sure you need a new battery.

I'm always happy to learn something new but I've always thought a battery would have longer life in warm/hot climates as opposed to cold?

I have 3 UPS, always appear to need a new battery after 18 months..... All of them are named GIZZ so if was not the battery then can use the battery in another UPS, from the little discount store down the road cost 420 baht.. noticed in Pantip 2 there were 100 baht more

Re car batteries when I had the Honda Jazz all 3 batteries lasted 14 months each.. [Honda charged 869 baht for the 1st one then 970 baht to supply and fit a new one]

The much bigger battery in my Audi A6 is over 3 years old and starts 1st time even if I do not use the car for 7 - 10 days..

You are lucky to get more than 2-3 years service on a sealed battery in these temperatures. Am sure you need a new battery.

I'm always happy to learn something new but I've always thought a battery would have longer life in warm/hot climates as opposed to cold?

No the life is considerably shortened - suspect you are thinking about how well they work rather than there life.

Temperature effects

Chemical reactions internal to the battery are driven either by voltage or temperature. The hotter the battery, the faster chemical reactions will occur. High temperatures can thus provide increased performance, but at the same time the rate of the unwanted chemical reactions will increase resulting in a corresponding loss of battery life.

http://www.mpoweruk.com/life.htm

Edited October 23, 200916 yr by lopburi3

Update: Based on a suggestion I found elsewhere, I did a deep discharge of the battery (using my halogen lamp), reinstalled the battery in the UPS and let it charge overnight. Tested the UPS this morning with an external hard drive. The battery had enough charge to power the drive for several minutes. So, now I know that it's the battery and not the UPS: the charging and battery sensing circuits are still OK.

And, I learned a lot about batteries and UPS.