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hdp asked

24V system MPPT

Good day,

Regarding a 24V system, what does the MPPT manual mean by the following indicated in bold below?

"3.3 PV configuration (also see the MPPT Excel sheet on our website) ● The controllers will operate only if the PV voltage exceeds battery voltage (Vbat). ● PV voltage must exceed Vbat + 5 V for the controller to start. Thereafter minimum PV voltage is Vbat + 1 V. ● Maximum open circuit PV voltage: 150 V or 250 V, depending on model.

For example: 24 V battery, mono- or polycristalline panels, max PV voltage 150 V: ● Minimum number of cells in series: 72 (2x 12 V panel in series or one 24 V panel). ● Recommended number of cells for highest controller efficiency: 144 cells (4x 12 V panel or 2x 24 V panel in series). ● Maximum: 216 cells (6x 12 V or 3x 24 V panel in series).

48 V battery, mono- or polycristalline panels, max PV voltage 250 V: ● Minimum number of cells in series: 144 (4x 12 V panel or 2x 24 V panel in series). ● Maximum: 360 cells (10x 12 V or 5x 24 panel in series)"


Is 24V charging capped at 150V? (even with the 250V series)

48v battery
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1 Answer
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seb71 answered ·

They analyze two examples:

1. A 150/xx solar charger used with a 24V battery.

2. A 250/yy solar charger used with a 48V battery.

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