.... and a ginormous charger, or a shed load of smaller ones?

 

As others have pointed out in all honesty, it's not a realistic let alone cost effective solution being you are looking at realistically having to spend around $100,000 to set the system up.

If keeping those heaters running is that important putting in a large diesel generator system would be far more cost effective in the long run.

What do the heaters do anyway?

 

I don't know what you have available, but maybe a small steam turbine. What ever you do, it will require power.

Have you got anything you can burn? Natural gas perhaps?

A surplus marine steam generator?

 

Ideally about 600.

Hmm.. 25x10=250 . Wouldn't 3 pieces of 100amp hour batteries cover it ? How does the calculation goes ?

 

Hmm.. 25x10=250 . Wouldn't 3 pieces of 100amp hour batteries cover it ? How does the calculation goes ?

You're way in over your head.

Your heaters draw 25 amps per phase at 415 volts, NOT 12 volts, so that's ( 25 x 3 x 415 = 31125 watts per hour per heater) times 10 heaters so your total power draw is 311,250 watts per hour.

A common 12-volt 100 amp hour battery has, (12 x 100 = 1200) watt hours of energy it can store but that is typically rated on an 8+ hour discharge time, not a one hour discharge time. On a one hour discharge time you can figure you only get about the half the total stored energy out thus you need two batteries to get 1200 watt hours per hour, not just one battery.

Now given that you need to supply 311,250 watts for one hour from batteries so divide the 311,250 total by 600 and you get a rough number of batteries you need which in this case works out to around 520 batteries. (311,250 / 600 = 520) Not three.

I added an extra 80 batteries to account for at least 10% reserve power and to make up-conversion system efficiency losses as well. That's where my 600 12 volt 100Ah deep cycle batteries number came from.

However if you wanted to cut corners and run your battery banks to high levels of discharge greatly reducing their life you could get by with about 450 of them but your service life would likely only be a few dozen discharge cycles before their overall capacities started to drastically drop off.

 

You're way in over your head.

Your heaters draw 25 amps per phase at 415 volts, NOT 12 volts, so that's ( 25 x 3 x 415 = 31125 watts per hour per heater) times 10 heaters so your total power draw is 311,250 watts per hour.

A common 12-volt 100 amp hour battery has, (12 x 100 = 1200) watt hours of energy it can store but that is typically rated on an 8+ hour discharge time, not a one hour discharge time. On a one hour discharge time you can figure you only get about the half the total stored energy out thus you need two batteries to get 1200 watt hours per hour, not just one battery.

Now given that you need to supply 311,250 watts for one hour from batteries so divide the 311,250 total by 600 and you get a rough number of batteries you need which in this case works out to around 520 batteries. (311,250 / 600 = 520) Not three.

I added an extra 80 batteries to account for at least 10% reserve power and to make up-conversion system efficiency losses as well. That's where my 600 12 volt 100Ah deep cycle batteries number came from.

However if you wanted to cut corners and run your battery banks to high levels of discharge greatly reducing their life you could get by with about 450 of them but your service life would likely only be a few dozen discharge cycles before their overall capacities started to drastically drop off.

Thank you so much for the wonderful explanation .

 

Hi I have 10 heaters running at 25 amp each .

What rating lead acid batteries should I get if I want to run them for 1 hour ? In the case of a power shortage.

Thank you .

If you are still considering batteries there are things like the 2CRP3690 that supplies 2550 Amp-hours at 20 hours rate. "Power company" size battery. 3,690 Amp-hour, maximum. Cost about $1,100 each, 2 V. How many you need depends on the motor-generator it drives. So we have a battery turning a motor that turns a generator that generates the electricity, as opposed to a diesel motor driving the generator.