Hi All,

I’m looking for some help configuring my system.

System is as follows:

Radian 8KW GS8048A Inverter

Mate3 - Firmware 3.15.3

2 – FM80 Charge Controllers

1 – Flexnet DC

Hub10

7200W solar array.

2 – 48VDC Deka Maxpwr series 24-125-17 forklift batteries. 2 years old. 3560AH total usable capacity.

Capacity of each battery is 1130AH 6 hr rate, 1780AH 20AH rate. These batteries are rated to normally go to 80% DOD.

The AH rating leaves a 20% reserve capacity. So the 1780AH is my usable capacity for each battery.

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Deka has provided me with some information that is a little confusing when translating it to settings to use on the Radian.

Below is the text of the information from Deka:

The Max-Powr cells you are using are considered P140-17 cells and are rated at 1120 ampere hours at the six (6) hour rate. Full charge specific gravity is 1.320 @ 77 Degrees F. These Max-Powr cells are considered Motive Power cells, therefore, some of the setting questions you have listed will not apply to this product. A typical charge profile for the Motive Power battery is as follows:

Charger start rate: 16-20 amps per 100ah rating of the battery.

80% charge: 2.37 volts per cell.

Finish rate: 5 amps per 100ah rating of the battery.

Equalize Charge: 3 to 5 amps per 100ah rating of the battery for 3 hours after full charge on a weekly basis.

80% Depth of Discharge: 2.00 volts per cell, Open Circuit.

Float Voltage: 2.25 – 2.27 volts per cell.

The 2.37 volts per cell is the on-charge voltage at 80% state of charge. The 2.00 volts per cell is the open circuit cell voltage at 80% depth of discharge.

Full charge voltage, open circuit, should be 2.12 – 2.15 volts per cell on a healthy Max Powr battery.

The full charge specific gravity for a Max Powr battery should be 1.320 – 1.325 corrected for 77 Degrees F.

The on charge at finish rate of 5 amps per 100ah for a healthy Max Powr battery will range between 2.60 to 2.70 volts per cell.

I would recommend the Absorb End Amps would be very low somewhere around 15 amps to maintain a float voltage of 2.25 to 2.27 volts per cell, after the cells are fully charged and confirmed by specific gravity data. The Absorb End Amps will depend upon the health of the cells and you are correct, the End Amps will increase as the cells age.

What I am looking for the system to do is:

1.Supply the house load using power from the panels.

2. Keep batteries at full charge until the panels can no longer support the load.

3. Export excess power to the grid after #1 & #2 are met. But not use battery power to produce power for export. Export only excess solar power.

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I am seeing that the system is providing power to the house and is exporting to the grid. It also starts using battery power to produce extra power to export to the grid. I want the batteries to remain at as full a charge as possible during the day so it will be available to use at night or on cloud days.

Present settings:

Mate3

Global Charge

Max Battery Charge – 150Amps

GS8048A

Battery charging

Absorb Voltage – 64VDC

Absorb Time – 4 hours

Float Voltage – 54.4

Re-Bulk Voltage – 50.4

Float time – 4.5 hrs

Re-Float Voltage – 50VDC

Eq Voltage – 64.8VDC

EQ Time – 1.1 hrs

AC Input

General

AC Input Select Priority – Grid

Charge Operating – Off

Charger AC Limit – 30AAC

Grid

Grid input mode – GRID TIED

Grid-Tie – Yes

Sell Voltage – 52.8VDC

FLEXnet DC

Battery charging

Battery AH 3560

Charged Voltage – 64.8

Charged Time – 20 min

Charged Return Amps – 28A

Charge Factor – 90%

FM80

Battery Charging

Absorb Voltage – 64.8

Absorb Time – 4hrs

Absorb End Amps – 18ADC

Re-Bulk Voltage – 52VDC

Float Voltage – 54.4

Current Limit – 75ADC

Eq Voltage – 64.8VDC

Eq time – 1Hr

Auto Eq Interval – 0 Days

Misc

Grid-Tied Mode - Enabled

Auto Restart Mode – Off

Wake VOC Change – 6VDC

Wake Interval – 5 Min

Battery Voltage Calibrate - -0.5VDC

Any help would be appreciated. Please let me know if there is any other information needed.

Thanks

Dirk