Difference Between Online UPS Battery and Offline UPS Battery

The only difference between an on-line UPS' battery and an off-line one, is that the equipment is taking power from the mains in the first case, and it isn't in the second.

See #1.

The one information you got doesn't sound very sensible, either.

...so if there is no difference, it would be unlikely that anyone can.

As long as the voltage, amp hour capacity,charge, and discharge rates are the same it doesn't matter what battery is doing what or where.

The online or offline function is more or less determined by the circuitry not the battery set.

Google and other search engines must be having a hard time staying in business, since it is obvious that very few use them any more.

No doubt our usage of these terms elsewhere contributes to the confusion. For instance: An offline power supply actually uses the utility power for it's energy source because it is working "off the lines". Wouldn't that really be an online power supply?? Oh, well. (English is a wonderfully confusing language without doubt)

At any rate, yes the current vernacular of the UPS industry is to define a "double-conversion" UPS as one that provides power continuously from the battery-fed inverter and a separate battery charger that is powered from the utility power maintains the charge on the battery, hence double-conversion as Cuba_Pete aptly stated.

The other typical style UPS is usually referred to as a "line-interactive" UPS where the inverter is in a stand-by mode waiting for a power failure at which time it is switched on and fed by the battery. There is usually several milliseconds of delay from utility power drop-out until the inverter is able to begin feeding power to the loads. Systems that cannot tolerate the momentary glitch, will generally use the double-conversion UPS.

A line-interactive UPS can generally use a smaller battery charger (less expensive) than the double-conversion UPS because it only needs to maintain the charge on the battery and not required to provide continuous full rated power.

Cheers !!

On line UPS always feeds the load through the inverter and the battery get loaded to feed the inverter.

Off line UPS lets the load feed on the grid instead of on the inverter. Once there is a power interuption the inverter takes over.

In both systems the battery is loaded by the grid,

I stop here.

There are actually three types of UPS's online, offline and line interactive. In an offline system the load is normally provided for by the input power and the backup is only called upon when the power supply fails. An online system converts the AC input into DC current for charging the rechargeable battery and then converting the DC current back to AC current to power the equipment. This is a double conversion method. A line interactive system uses an inverter to supply current when the power supply is lost by redirecting current from the regular charging mode of the inverter.

The offline UPS connects the equipment directly to a power supply. It only provides basic features such as battery backup and surge protection. Whenever there is a variance in the input supply, the system within milliseconds switches on the circuitry which converts the DC current available in the battery to AC current and supplies it to the device. The time taken to switchover from the input supply to the backup supply depends on the time taken by the circuitry to find the lost voltage. This type of UPS can only be used for equipments like home computers which require very little power and can handle fluctuations in the supply

The online UPS is considered ideal for equipment that is sensitive to fluctuations in the power supply or for environments in which electrical isolation is essential. In most countries nowadays electrical anomalies like outages, sag in utility power, etc., are a common occurrence. The basic components of an online power system is similar to that of the offline UPS. This type of UPS also has 2 supplies and transfer switch that selects between the power supplies. The difference is that the primary supply of the UPS is the UPS's battery and the secondary supply is the mains.

Each system has its own unique advantages and disadvantages. The advantage of the offline UPS is that the initial cost is less, the efficiency at which the system operates is really high, and it is silent during operation. The advantage of the online UPS is that not only does it provide continuous power conditioning there is also no break when the mains fail and it has a wide tolerance range of input voltage. However this type UPS is more expensive than the other UPS systems. But when comparing both the online and offline UPS, the online UPS clearly has the upper hand barring the difference in price.

So, back to the OP's question (who is apparently absent)...

Why would their online and offline batteries be incompatible?

At least, that is how the question translates in my mind.

This is what you call a drive by question, Just throw out a Crappy question with lithle or no understanding of what you are asking and none of the data necessary to allow for an adequate answer just to see if anyone is bored enough to waste their time discussing it. (this only works on an engineering website) Then they come back every once in a while to see how many bored engineers there are! I think its a game, kind of like fly paper for bored and retire engineers

Without actually having the battery specs, it is difficult to say what will work.

• What are the battery specifications
• Voltage?
• Amp hour rating?
• Physical size?
• Model number?

Compare these to the system you want to install it in. If the voltage is the same, probably 12VDC then your Amp hour rating and physical size are what matters!