74 replies to this topic

[koder]

Ijaz Ahmed what will be the difference in the backup timming between a dry battery which is used in those BTS of telenor,ufone,zong etc with the Volta 210amp battery? the condition of volta battery is very good.

[Ijaz Ahmed]

^ IMO: It is the AH capacity of the battery which determines the backup time, given the same capacity batteries the backup time should be same (be it dry or wet battery).

[Myelin]

Simple formula:

wattage required or used by equipment / volts of battery * hours of backup

so

if i require 2 energy savers of 23 watts and i am using 12 volts battery and i want 3 hours backup i would need

46/12*3=
3.84*3=12

I would need 12 AH battery for my 2 23 watts energy savers to work for 3 hours!

[nvd650]

Ijaz Ahmed, on 27 February 2012 - 05:48 PM, said:

^ IMO: It is the AH capacity of the battery which determines the backup time, given the same capacity batteries the backup time should be same (be it dry or wet battery).

Here I'll differ you a bit, you are talking logically Volta batteries are not exactly what they say, it they say it is 210 AH then it's actualy max 180 AH. while if both batteries are really branded (branded never meant used) then yes I'll agree with you, in his case if he buy 150 AH of Aurora then it will give more time than 210 AH Volta for sure

[nvd650]

Myelin, on 27 February 2012 - 08:18 PM, said:

Simple formula:

wattage required or used by equipment / volts of battery * hours of backup

so

if i require 2 energy savers of 23 watts and i am using 12 volts battery and i want 3 hours backup i would need

46/12*3=
3.84*3=12

I would need 12 AH battery for my 2 23 watts energy savers to work for 3 hours!

You did not included energy/line losses, and also VA of said energy saver....

[Asad]

Keep in mind that battery capacity rating is at a particular discharge rate. A battery rated at 150Ah at C/10 might only give 135Ah at 1C and 120Ah at 10C and so on. I am just assuming the usable capacity with respect to discharge C rate to give a very general idea. Usage with UPS typically requires high C rate discharge resulting in less usable capacity before the cutoff/low voltage is reached. Other factors like IR also play their part.

[Ijaz Ahmed]

nvd650, on 27 February 2012 - 11:57 PM, said:

Here I'll differ you a bit, you are talking logically Volta batteries are not exactly what they say, it they say it is 210 AH then it's actualy max 180 AH. while if both batteries are really branded (branded never meant used) then yes I'll agree with you, in his case if he buy 150 AH of Aurora then it will give more time than 210 AH Volta for sure

If you don't get what is says on the tin, that's not a problem of Laws of Physics.

I agree with your observation since our manufacturers tend to use misleading model numbers and what you think is not what you actually get.

[ZXCVB]

2KVA 24 volt inverter will need a 24 volt battery?

are 24 volt batteries available or one has to use two 12 volt batteries in series

[Ijaz Ahmed]

ZXCVB, on 28 February 2012 - 10:17 AM, said:

2KVA 24 volt inverter will need a 24 volt battery?

Most likely it will be 24V

ZXCVB, on 28 February 2012 - 10:17 AM, said:

are 24 volt batteries available or one has to use two 12 volt batteries in series

24V single battery is not commonly (or at all) available, so you will have to use 02 batteries of 12V each. Remember to use the same AH rating batteries, preferably same make / model.

[blogger]

ZXCVB, on 28 February 2012 - 10:17 AM, said:

2KVA 24 volt inverter will need a 24 volt battery?

are 24 volt batteries available or one has to use two 12 volt batteries in series

24 V is not a standard for a battery until or unless, it is especially designed for some commercial purpose or for some machine like electric scooter. As a standard, 24 volts inverter requires two standalone 12 volts batteries connected in series pole to pole. (Check the User Manual also)
While connecting batteries to an inverter or a UPS, one should take precautionary measures and never ever connect positive of inverter/UPS with negative of battery and vice versa. Always connect [+] with [+] and [-] with [-]. A mistake can burn your Inverter.

[hawker]

How can i check health of my battery?
I am using FB battery.
Maybe i need to test the liquid in the battery?

[Asad_N]

Ijaz Ahmed, on 28 February 2012 - 11:16 AM, said:

Most likely it will be 24V


24V single battery is not commonly (or at all) available, so you will have to use 02 batteries of 12V each. Remember to use the same AH rating batteries, preferably same make / model.

I was wondering why is it recommended to use the same AH batteries. From what I understand, it doesn't really matter in charging and different capacity batteries can be connected together. Does it differ in discharging?

[koder]

My UPS battery isn't decreasing the water from 3 4 months .. whats wrong with it

[Ijaz Ahmed]

Asad_N, on 28 February 2012 - 07:48 PM, said:

I was wondering why is it recommended to use the same AH batteries. From what I understand, it doesn't really matter in charging and different capacity batteries can be connected together. Does it differ in discharging?

We are talking about series connected batteries, am I right ?

There are reasons behind this recommendation and yes, it matters both in charging and discharging.

If you use two 12V batteries with different capacity, e.g. 100AH and 50AH in series, you will have a 24V battery bank with only 50AH capacity. This is because 50AH will discharge first and its terminal voltage will drop first, and you will be left with only 50AH remaining power in 100AH battery. This is obviously not desirable.

Now let's consider charging. The 50AH will charge first and its terminal voltage will reach nominal value. While 100AH will still continue to charge and the charging current must pass through the 50AH battery as well (remember this is series circuit), causing the 50AH battery to overcharge.

That is the reason why it is recommended to use same AH (preferable same make/model/age) batteries when those are to be used in series.

[Ijaz Ahmed]

koder, on 28 February 2012 - 08:00 PM, said:

My UPS battery isn't decreasing the water from 3 4 months .. whats wrong with it

Nothing wrong, you are near ideal situation. Water decreases due to evaporation and evaporation increases with temperature which in turn is caused by the heat from over-charging.

Your charger is in good condition.