I need to use solar panels with lead-acid batteries and 230V inverter. There are two putative connection configurations in my mind, with different consequences/requirements.
Components:
1) Solar panels, 2 in series, 412W, 40V at full power
**2) Putative charge controller Suoer ST-MP40A (can take PV up to 150V, rated 40A, with 40A DC output for DC load). The manual gives no specifications of the "DC output".
3) 2x 12V car batteries 100Ahr each, wired in parallel [yes I know, that doubles the current, but the inverter is 12V so I have to use 12V]
4) Inverter Suoer FPC-2000A (12VDC to 230VAC) rated for continuous 2000W peak 3000W in theory (I have doubts about that, but maybe so if the battery is humungus; at any rate it does provide 1500W as long as the battery is sufficiently well charged to remain above 10V under load). Inverter cut-off voltage is 10V under load.
5) Load 1450W resistive load (espresso machine). At the inverter cutoff of 10V, this is drawing 145A from the battery. It will need both battery and solar simultaneously to produce enough power.
** This item is the crux of the question: according to the configuration, either 40A is OK, or I need 150A rating if inverter is wired through controller.
1) First putative configuration: Ignore the "DC output", connect solar cells to controller, controller to battery, and inverter directly to battery without going through controller.
In this case the controller rating at 40A is adequate to handle output from up to 3 solar panels at full output, and the inverter current drawn from the battery is irrelevant. However my doubt is whether the charge controller needs to be able to measure load current in order to regulate the charge correctly? If I bypass the DC output, my fear is it will overcharge the battery and quickly destroy it, because by drawing current the inverter heavily depresses voltage.
2) Second putative configuration: Connect the inverter through the "DC output" of the charge controller. In this case the controller can monitor the load, and might be better equipped to charge the battery correctly, but I would then need a far bigger charge controller.
(1) or (2)?
Components:
1) Solar panels, 2 in series, 412W, 40V at full power
**2) Putative charge controller Suoer ST-MP40A (can take PV up to 150V, rated 40A, with 40A DC output for DC load). The manual gives no specifications of the "DC output".
3) 2x 12V car batteries 100Ahr each, wired in parallel [yes I know, that doubles the current, but the inverter is 12V so I have to use 12V]
4) Inverter Suoer FPC-2000A (12VDC to 230VAC) rated for continuous 2000W peak 3000W in theory (I have doubts about that, but maybe so if the battery is humungus; at any rate it does provide 1500W as long as the battery is sufficiently well charged to remain above 10V under load). Inverter cut-off voltage is 10V under load.
5) Load 1450W resistive load (espresso machine). At the inverter cutoff of 10V, this is drawing 145A from the battery. It will need both battery and solar simultaneously to produce enough power.
** This item is the crux of the question: according to the configuration, either 40A is OK, or I need 150A rating if inverter is wired through controller.
1) First putative configuration: Ignore the "DC output", connect solar cells to controller, controller to battery, and inverter directly to battery without going through controller.
In this case the controller rating at 40A is adequate to handle output from up to 3 solar panels at full output, and the inverter current drawn from the battery is irrelevant. However my doubt is whether the charge controller needs to be able to measure load current in order to regulate the charge correctly? If I bypass the DC output, my fear is it will overcharge the battery and quickly destroy it, because by drawing current the inverter heavily depresses voltage.
2) Second putative configuration: Connect the inverter through the "DC output" of the charge controller. In this case the controller can monitor the load, and might be better equipped to charge the battery correctly, but I would then need a far bigger charge controller.
(1) or (2)?
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