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Hey guys,
I have an RV that came with a Sunforce 7A charge controller with a 13V/14.2V cut-in/cut-out. It doesn't have any other readings other than an orange "charging" and "green" charged light. I have a removable flexible 100W solar panel hooked up to it. This all wires in to 2 100Ah lithium polymer batteries.
I have a voltmeter hooked up to the batteries. When I connect the solar panel I usually see a rise of 0.1-0.2V...or so I thought. Today I noticed that the voltage is 13.1V when the panel is disconnected and 12.9-13.0 when the panel is connected! What could explain a voltage drop when I connect the panel?
Update: After some more time and putting a bit of load on the batteries, the voltage started behaving how you would expect. It's now at 12.7-12.8 without the panel and 12.9-13.0 with the panel. I would still love to hear what explanations you guys have for the initial behavior. Why was it showing 13.1V without the panel and less with it? The truth is I did in fact expect the batteries to be more at 12.8-12.9V rather than 13.1V. What kind of battery effect could cause a higher reading than reality (maybe without load)?
I have an RV that came with a Sunforce 7A charge controller with a 13V/14.2V cut-in/cut-out. It doesn't have any other readings other than an orange "charging" and "green" charged light. I have a removable flexible 100W solar panel hooked up to it. This all wires in to 2 100Ah lithium polymer batteries.
I have a voltmeter hooked up to the batteries. When I connect the solar panel I usually see a rise of 0.1-0.2V...or so I thought. Today I noticed that the voltage is 13.1V when the panel is disconnected and 12.9-13.0 when the panel is connected! What could explain a voltage drop when I connect the panel?
Update: After some more time and putting a bit of load on the batteries, the voltage started behaving how you would expect. It's now at 12.7-12.8 without the panel and 12.9-13.0 with the panel. I would still love to hear what explanations you guys have for the initial behavior. Why was it showing 13.1V without the panel and less with it? The truth is I did in fact expect the batteries to be more at 12.8-12.9V rather than 13.1V. What kind of battery effect could cause a higher reading than reality (maybe without load)?