Two situations here.
I recently decided to power a detached garage with an off-grid Windy Nation system. A 100W PV, 30A controller, 1500W PSW inverter, and two 100AH lead acid batteries. (Great service and support from the vendor). The system powers the opener and a few lights. For fun, I also have began to use it to power a shop vac, leaf blower to blow out the garage, a deck fan, and sometimes I will run an extension cord to the house to run the computer. (Here in Denver there is a lot of sun and I hate to see power wasted when the system is full). I make sure that the batteries never drop below 12.2 volts.
I have notice that the batteries are drawn down quickly when using a 120 watt appliance. Based on 1200 watt hours, I should be getting 10 hours. Even with the charging amps at 4 or 5 during the day, I am lucky to get 30 minutes before I have to pull the plug on the appliance. I think that's odd. Any thoughts?
Also, in Will's excellent video (16:50 below) he talks about charge time. Okay, so you take 1/2 of the lead acid battery's watt hour rating and multiply that by 70% of the PV's output, that will give you the charging time. But wouldn't that be in the absolute best charging conditions? How would you calculate an accurate expected charging time - do you multiply the voltage times the amperage that it being generated at that exact time? Obviously it changes. I don't understand when Will says that the charging time is x-number of hours. I would think you would also need the amperage.
Thanks - I am new at this (obviously).
I recently decided to power a detached garage with an off-grid Windy Nation system. A 100W PV, 30A controller, 1500W PSW inverter, and two 100AH lead acid batteries. (Great service and support from the vendor). The system powers the opener and a few lights. For fun, I also have began to use it to power a shop vac, leaf blower to blow out the garage, a deck fan, and sometimes I will run an extension cord to the house to run the computer. (Here in Denver there is a lot of sun and I hate to see power wasted when the system is full). I make sure that the batteries never drop below 12.2 volts.
I have notice that the batteries are drawn down quickly when using a 120 watt appliance. Based on 1200 watt hours, I should be getting 10 hours. Even with the charging amps at 4 or 5 during the day, I am lucky to get 30 minutes before I have to pull the plug on the appliance. I think that's odd. Any thoughts?
Also, in Will's excellent video (16:50 below) he talks about charge time. Okay, so you take 1/2 of the lead acid battery's watt hour rating and multiply that by 70% of the PV's output, that will give you the charging time. But wouldn't that be in the absolute best charging conditions? How would you calculate an accurate expected charging time - do you multiply the voltage times the amperage that it being generated at that exact time? Obviously it changes. I don't understand when Will says that the charging time is x-number of hours. I would think you would also need the amperage.
Thanks - I am new at this (obviously).
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