xibalban
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I find most people using the following formula to estimate energy outputs from a battery for a given load:
Assume a 12 V, 50 Ah battery (deep discharge type)
Assume a load of 100 Watts, so using power formula
P = VIcosΦ
Or I = P/V [assuming power factor = 1]
I = 100/12 = 8.33 A
Now, h = Ah/A
= 50/8.33 = 6 hours
So, the 12 V, 50 Ah battery would last 6 hours on a constant load of 100 Watts. Right?
However, we assumed that the voltage 'V' of the battery remains constant, which isn't true. The battery voltage keep diminishing, and hence the current drawn by the load keeps increasing. We need a better formula for estimating the "hours" above, don't we?
What, may I request, is the true solution?
Thanks in advance.
Assume a 12 V, 50 Ah battery (deep discharge type)
Assume a load of 100 Watts, so using power formula
P = VIcosΦ
Or I = P/V [assuming power factor = 1]
I = 100/12 = 8.33 A
Now, h = Ah/A
= 50/8.33 = 6 hours
So, the 12 V, 50 Ah battery would last 6 hours on a constant load of 100 Watts. Right?
However, we assumed that the voltage 'V' of the battery remains constant, which isn't true. The battery voltage keep diminishing, and hence the current drawn by the load keeps increasing. We need a better formula for estimating the "hours" above, don't we?
What, may I request, is the true solution?
Thanks in advance.