Battery bank capacity

[kicglobal]

Pls. clarify or describe in detail about the under mentioned battery bank;

2V/600Ah @ 120Hrs.

Now, what would be the battery bank size if 24 above batteries are connected in 48V series system?

Second, how long would be the backup time when fully charged, if 3000Watts are drained every hour?

Third, if replacement is needed, how many 12V/150Ah batteries are required?

[Sunking]

Pls. clarify or describe in detail about the under mentioned battery bank;

2V/600Ah @ 120Hrs.

The theoretical watt Hout Capacity of any battery is watt hour = voltage x amp hours. From that equation every question of yours can be answered , however in theory only, not application because Mr Puekert and his law of physics will get into the act.

Now, what would be the battery bank size if 24 above batteries are connected in 48V series system?

[48 v x 600 ah] / 3000 w = 9.6 hours. OK this is where Mr. Puekert will rob you blind. The rating you of 600 AH is at the 120 hour discharge rate or 600/120 = 5 amps. You now have increased the discharge rate to 9.6 hours 600 / 9.6 = 62.5 amps. This will turn your 600 AH battery into something much less than 600 AH. How much is hard to say. but good battery manufactures will publish the various AH capacities all the way down to 1 Hour. Just guessing using an average the correction factor would be .6 so now you are looking at [48 x 600] / 3000 x .6 = 5.76 hours. Of course you would never ever want to discharge to 100% DOD. The max would be 50% DOD which now cuts you down to 2.8 hours.

Third, if replacement is needed, how many 12V/150Ah batteries are required?[/FONT]

[48 x 600] / [12 x 150] = 16

[kicglobal]

Pls. clarify or describe in detail about the under mentioned battery bank;

2V/600Ah @ 120Hrs.

Now, what would be the battery bank size if 24 above batteries are connected in 48V series system?

Second, how long would be the backup time when fully charged, if 3000Watts are drained every hour?

Third, if replacement is needed, how many 12V/150Ah batteries are required?

Many thanks for the explanations.

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It establishes that better go for 12V/150AH @ C20 rating sixteen batteries to make 48V in series and (48*600) 28,800W rather 2V/600AH @ 120hrs. twenty four batteries to make 48V in series. Am i right?

24 batteries will cost more and consumes more electrolite around 11.3 Ltrs. per battery. Maintainance & space is also more hard than 16 nos.

Second, if printed @ C20 or @120hrs. means same rating?

[Sunking]

It establishes that better go for 12V/150AH @ C20 rating sixteen batteries to make 48V in series and (48*600) 28,800W rather 2V/600AH @ 120hrs. twenty four batteries to make 48V in series. Am i right?

24 batteries will cost more and consumes more electrolite around 11.3 Ltrs. per battery. Maintainance & space is also more hard than 16 nos.

Second, if printed @ C20 or @120hrs. means same rating?

No it does not mean that at all. You are not comparing apples to apples using the 20 hour discharge rate compared with a 120 discharge rate. You have ignored stingy Mr Peukert Effect. Look at this classic example of a Rolls Battery.


Note the 20 hours capacity compared to the 100 hour capacity. At 100 hours it is rated 293 Amp Hours. At 20 hours it is rated 220 AH. No go look at the 4 hours discharge rate we used earlier for your 3000 watt at 48 volt example. It goes all the way down to 143 AH. Sizing to 100 hour discharge rate AH and using the 4 hour rate is over a 100% difference in capacity.

For batteries you always want to use a single string if possible. Using Multiple strings takes extreme care in design and operations.

[kicglobal]

Followed your points. Now, how we can calculate Ah capacity down to 1 hr. at our end?

[Sunking]

Followed your points. Now, how we can calculate Ah capacity down to 1 hr. at our end?

Look at the manufacture discharge curves or tables like I showed you.