02-07-2020, 08:32 AM

Reading through the forums, most of the experienced users recommend 48 Volts.

I know, each KW is only 20 Amps, so 80 Amps will get you 4 KW, nice and tidy using a PIP4048.

However, I am now going to tell You that I have changed to 24 Volts.

Why?

My first setup was 48 Volts, a PIP4048 and approx 15 KWh of usable lead-acid battery capacity.

In the Summer when Sun was plentiful, PIP´s "household" consumption of 50+ Watts, did not matter at all.

However, even here in Denmark, we have seasons, and in the Autumn the Sun declines rapidly, and in early November, Sun input starts to struggle keeping up with the PIP´s self consumption leaving almost nothing for everything else.

So, in November, December, January and half of February, I have to charge from the Grid to avoid my Batteries being totally depleted.

This also goes for my present 7P7S100P LiIon storage.

Here is what I calculated: PIP consumption during "winter": 105 Days times 50+ Watt times 24 Hours = at least 126 KWh with no load at all.

So, I went for 24 Volts, I am now restricted to 3 KW output power in the Winter using only one 3 KW Inverter, but "household" consumption is more than halved.

This gives me almost 70 KWh for consumption or charging saved.

In the Summer with plenty of sunshine, I simply light up one more 3 KW inverter.

I see only one penalty: I need more cables to carry the extra Amperage.

ChrisD

I know, each KW is only 20 Amps, so 80 Amps will get you 4 KW, nice and tidy using a PIP4048.

However, I am now going to tell You that I have changed to 24 Volts.

Why?

My first setup was 48 Volts, a PIP4048 and approx 15 KWh of usable lead-acid battery capacity.

In the Summer when Sun was plentiful, PIP´s "household" consumption of 50+ Watts, did not matter at all.

However, even here in Denmark, we have seasons, and in the Autumn the Sun declines rapidly, and in early November, Sun input starts to struggle keeping up with the PIP´s self consumption leaving almost nothing for everything else.

So, in November, December, January and half of February, I have to charge from the Grid to avoid my Batteries being totally depleted.

This also goes for my present 7P7S100P LiIon storage.

Here is what I calculated: PIP consumption during "winter": 105 Days times 50+ Watt times 24 Hours = at least 126 KWh with no load at all.

So, I went for 24 Volts, I am now restricted to 3 KW output power in the Winter using only one 3 KW Inverter, but "household" consumption is more than halved.

This gives me almost 70 KWh for consumption or charging saved.

In the Summer with plenty of sunshine, I simply light up one more 3 KW inverter.

I see only one penalty: I need more cables to carry the extra Amperage.

ChrisD