Battery

[Wes]

What do the battery inside the UPS only last a year or two while those in the car can last for years and can still start a car with ease?

While the power was out yesterday, none of my UPS worked...

[Ninjahedge]

Depends on the type of battery

Car batteries (and shifty will correct me on this) are simpler constructions that rely on a lead-acid reaction.

I will have to look up my chemistry on this if I get more in depth, but I believe that the reason why these batteries last longer is mainly because it is a simple set of electrodes of differing EMP with an acid based electrolytic solution.

Most other batteries are not as robust, as they are made from different substances (probably to get higher voltages and still remain portable). The main problem with them probably being the drying out of the electrolyte or the oxidation of the electrodes from external sources (you can't completely isolate a battery).

Some info here:

http://en.wikipedia.org/wiki/Battery_(electricity)

I know it is Wiki, but C'mahn!

I believe that the overall life of the battery probably has more to do with the sheer fact that your electrodes are so much bigger in a car battery than a NiMh, Li-Ion or other cell it probably takes longer to contaminate and expend them through external electrochemical reactions....

[Dr. Death]

Most UPS batteries are sized only to allow orderly shutdown of the computers attached to them. That's usually about 15 minutes. So say you have a 400 watt UPS, and you've got 400 watts of equipment (computer and monitor) attached, you will only get 15 minutes of "on" time (again, it depends on the specs for the UPS.) Lower that load to 100 watts, and you may get an hour.

Many good UPS units (I have Powerware 9120 and 9125 units that have this) have a battery test feature and battery replacement alarm.

Also, most low-cost UPS units don't have full isolation, so the batteries sit there on standby and are not used most of the time. If your UPS doesn't periodically test the batteries, or you don't test them yourself, you have no way of knowing if your unit will work when it's crunch time.

The best way to stay on line during an extended power outage, is to get a large UPS, and hook your router and cable/FiOS modem to it, and use a laptop that doesn't tap the UPS. You can charge the laptop battery from your car, with an inverter. If you're running servers that need to stay on line, a generator is called for.

[garm]

my ups battery died recently too. I've had my ups back up for about 2 years now and then one day it flashed a message on my computer that it was time to replace the battery. During that 2 year timeframe, the ups wasn't used that often.

I paid about 200 for it at the time. Definitely not a professional level equipment, but I would have hoped to get more than 2 years out of it.