Which Would be Better, 12V UPS or 24V UPS?

The main point is the AH rating of the battery which will determine the back up time afforded by the system. If your back up time requirement is within the maximum available rated Ah battery, it is enough to go for single battery system instead of burning a hole in your pocket. Technically 24 volt system is better because of better efficiency but will be offset by higher cost and space requirement.

Dear Mr. Pattabhiraman,

Here from the original post, as I understand, that the consideration, under the identical working condition, whether it is better to have 24 Volts system or 12 Volts System. Hence the back up will be the same for both voltages, as there is no reference about back-up.

Pl. clarify.

DHAYANANDHAN.S

Sir, Mr. Signode missed providing the deciding factor. The maximum Ah rating of 12 v battery will be the determinant. Regards Pattabhiraman

It all comes down to determining the time back-up power will be required, or planned for. #1 above gives many good points.

Do you need the extra time built into the system, or not?

Suppose you have an engine that consumes 1 liter of petrol/hour.

A 12 liter tank will easily supply the engine for 12 hours.

A 24 liter tank will easily supply the same engine for 24 hours, but the cost is 25% higher for the system.

So, do you want a 12 hour supply,or a 24 hour supply?

Dear Mr. lyn,

In my opinion, the VI i.e V x I is the consideration, where as you have considered 12 litres and 24 litres for capacity, which may not match to the OP.

Pl. enlighten on this.

DHAYANANDHAN.S

Simply an analogy to put the problem in a different context.

Just ignore it.

I understood what you were saying, but maybe you should have put it like this :

12 doughnuts will keep a cop occupied for roughly 12 minutes.

24 doughnuts will keep him occupied for 24 minutes.

24 doughnuts cost double, how long do need the cop occupied?

My problem is that I try to keep things simple.

Some people have no capacity to think in simple terms and can only understand mathematical formula, whereas I prefer to use simple language.

Oh, easy to understand, hmmm, ok how about 12 beers or 24 beers?

Sorry, at work, partial crew, bored out of my gourd.

Well, you can't do anything with just 12 beers.

One of my old drinking buddies, who was in the Navy, told me once that he didn't even start counting until after at least 3 beers.

What was the subject again? I forgot.

Dear Mr. Signode,

You your self have raised the question and you your self answered, for 24 Volts is preferred and the merits have been indicated, by you. Of course 24 volts is preferred.

Then what is the issue you want CR4 Members to give their suggestions.?

DHAYANANDHAN.S

Dear DHAYANANDHAN.S

I have less experience in this field. So I shared what I have the knowledge about it and then asked to members about their opinion based on their experience.

One USA engineer once told to me "never assume any thing, always ask and clear yourself". So, "asking a question is better than assuming wrong".

I have collected much information by asking questions in Cr4.

Dear Mr. Signode,

Thank you for your reply and happy to note your approach, of ASKING and DOUBTS CLEARED. Some times hesitation will lead to problem.

DHAYANANDHAN.S

Greetings Signode,

The piece of the puzzle that is crucial to any discussion along these lines is this....

How long does it take you to back up and shut down?

Then buy the UPS that gives you that amount of time plus whatever extra margin your comfortable with.

The whole point of the UPS is to allow you time to save your files and shut down, not continue operations until power is restored. Things that provide that level of power are called generators