Cheap China Solar Controller Failure
For a couple days been noticing higher than the 14.6 voltage,.....going to 15, and even 15.5,....I knew something was not right. The next day it was showing 16, then quickly went to 17+.......I quickl...
Forum Discussion
Batteries are rated in Ah's, and charge controllers are rated in amps, not watts. So, I agree, thinking in terms of watts is rather confusing, if not irrelevant. Watts are inevitably converted to charging amps, so it's the final product that counts, not how you got there, neccessarily. And in the case of running loads, loads are rated in amps, not watts. So even if your fridge is rated at 300 watts, is that 2.5a at 120v, or 2.8a at 108v? In the end, it all comes down to amps and Ah's.
In a given set of circumstances, if mppt does this, that, and the other thing, and puts out 8a at a given charge voltage, while pwm takes a different (simpler) approach, but produces the very same 8a, at the same given charge voltage, then there is nothing to 'get', really. Just different approaches with the same result.
What's easier to understand; miles per gallon, or litres per 100 kilometers? I grew up with metric, and still, the former is way easier.(Interestingly, both are commonly referred to as mileage, not kilomerage).
If I'm trying to determine my daily usage, I do it in Ah's. Likewise, if I'm sizing a solar system, accordingly, I ask how many watts will it take to produce x number of Ah's. When replacing battery capacity used, I do it in Ah's needing to be replaced. Voltage and amperage (i.e; wattage)is merely a means to an end. Yes, specific voltages and amperages are necessary to achieve the goal of full capacity, but capacity is still the goal, and capacity is rated in Ah's.
If using 12v fans, pumps, lighting, etc., it is amps draw that counts, not the subtle variances in how many volts, exactly, any one device uses. Imagine, having to figure out the wattage used for each and every 12v device? Hmmm, this one draws .7a @ 11.8v, but this one draws 1.8a @ 12.6v, and so on...
All that matters is amp draw, per hour, per day. Ah's in and Ah's out, is all that really matters. Replacing Ah's is the goal, while the methods of achieving that goal can vary widely.
In a given set of circumstances, if mppt does this, that, and the other thing, and puts out 8a at a given charge voltage, while pwm takes a different (simpler) approach, but produces the very same 8a, at the same given charge voltage, then there is nothing to 'get', really. Just different approaches with the same result.
What's easier to understand; miles per gallon, or litres per 100 kilometers? I grew up with metric, and still, the former is way easier.(Interestingly, both are commonly referred to as mileage, not kilomerage).
If I'm trying to determine my daily usage, I do it in Ah's. Likewise, if I'm sizing a solar system, accordingly, I ask how many watts will it take to produce x number of Ah's. When replacing battery capacity used, I do it in Ah's needing to be replaced. Voltage and amperage (i.e; wattage)is merely a means to an end. Yes, specific voltages and amperages are necessary to achieve the goal of full capacity, but capacity is still the goal, and capacity is rated in Ah's.
If using 12v fans, pumps, lighting, etc., it is amps draw that counts, not the subtle variances in how many volts, exactly, any one device uses. Imagine, having to figure out the wattage used for each and every 12v device? Hmmm, this one draws .7a @ 11.8v, but this one draws 1.8a @ 12.6v, and so on...
All that matters is amp draw, per hour, per day. Ah's in and Ah's out, is all that really matters. Replacing Ah's is the goal, while the methods of achieving that goal can vary widely.
