Solar wasted watts/volts
I am curious what happens to the watts /volts when your system is fully charged and you have no demand? Were does the extra power go?
Forum Discussion
There are calculators to estimate the output of 400W panel. Here is one that I used when planning my system https://pvwatts.nrel.gov/ but right now it doesn't seem to work, can't enter any city.
These calculators are based on historical data on solar radiation and weather for the last few decades, so they are as accurate as can be. Minor drawback is that they are meant for solar homes and provide data in KWH/month. Easy enough to multiply by 1,000 and divide by 12.7 and by 30.5, to get a daily AH data.
So, - run the numbers. If it comes short of needed 127 AH (and if this is really your average draw), getting more battery capacity will help to make it through some bad weather spell.
There might be 9 hours of daylight, but there are also mountains, trees, clouds, rain and low sun early and late in the day. Leave yourself a safety margin. I often hear a suggestion to add 50% to estimated solar harvest that you think you need, - and agree with this.
These calculators are based on historical data on solar radiation and weather for the last few decades, so they are as accurate as can be. Minor drawback is that they are meant for solar homes and provide data in KWH/month. Easy enough to multiply by 1,000 and divide by 12.7 and by 30.5, to get a daily AH data.
So, - run the numbers. If it comes short of needed 127 AH (and if this is really your average draw), getting more battery capacity will help to make it through some bad weather spell.
There might be 9 hours of daylight, but there are also mountains, trees, clouds, rain and low sun early and late in the day. Leave yourself a safety margin. I often hear a suggestion to add 50% to estimated solar harvest that you think you need, - and agree with this.
