Fortress Power Sol-Ark LFP Legacy Series User manual

Rev A 08-28-21
Fortress Power - Sol-Ark LFP Legacy Series Inverter Guide
Introduction
Battery Datasheets / Manuals: See “Downloads”section of individual product pages
Email: [e-mail]
Discord Support: https://discord.gg/kxX6QMjKFw
Phone: [phone] x 2
Hours: 9:00AM - 6:00PM EST –Use Discord for After Hours / Weekends
Warranty Submittal: https://www.fortresspower.com/warranty/
Step 1 –Getting Started. Turn each battery on individually while unpacking the batteries and note the voltage
of each battery as well as the serial numbers. If installing parallel batteries, use external 80A fuses (see Victron Lynx).
The batteries must be charged individually to within +/- 0.5V of each other before commissioning.
Pro tip: If a BMS error occurs when powering up the inverter, turn the batteries off. Connect the inverter and any
battery breakers so power can flow from the batteries to the inverter. Turn the batteries back on again, and then
turn the inverter back on again. This will allow the batteries to trickle charge the inverter i.e. “pre-charge”. You may
need to repeat this process up to three times to precharge the inverter enough for it to power up.
Step 2 –Program the first three tabs in the Battery Setup menu.
Touch the gear icon on the main SolArk home screen to find the Battery Setup menu. Program the
batt/charge/discharge tab as shown below.
Use Batt V charged –Use this option with
the LFP series batteries.
Use Batt % Charged –Do not use this
option.
Activate Battery –Does not actually
activate the battery but instead helps the
battery after deep discharges.
Max A Charge / Discharge –Start with the
settings recommended on the right. If they do
not provide enough instant power for the end
user, join our Discord group for adjusted
settings.
Join Our Discord Chat
0mV/C/Cell
0 mV/C/Cell
80A
100A
100 Ah per LFP5
200 Ah per LFP10
300 Ah per LFP 15
✓

Rev A 08-28-21
Fortress Power - Sol-Ark LFP Legacy Series Inverter Guide
Start V autostarts the grid or generator
charge when the battery hits that voltage. It
charges the battery to 100%. Avoid hitting
this voltage by programming the Time-of-Use
settings in the grid parameters.
Start % - disabled. Do not use % mode with
LFP-series batteires.
Float V / Absorb V set to 54.4V
Equalization set to 0 hours (disabled)
A –The amount the grid or generator charges
the batteries. Should not be more than 80A.
Grid Charge –Check for grid-tied arrays or
off-grid arrays with large generators.
Gen Charge –Check this box if tying a <8kW generator into the generator breaker on the Sol-Ark.
Shut down % - is the low battery cut off
point which either shuts down the inverter or
transfers to grid power. This value should be
raised to 51V if there is not grid or generator
charge on site to avoid regularly deep-
discharging the battery. Regularly cycling the
battery below 20% will reduce the Fortress
warranty.
Low Batt –provides an alert when the battery
hits this level. User adjustable.
Restart –determines when the battery
can be used again after reaching the
shutdown %.
Batt Empty V –Keeps a few volts in the battery to avoid locking the battery out during accidental deep
discharges.
Step 9 –Program Grid Parameters.
Go back to the home screen, touch the gear icon, and select “Grid Setup”. The Grid Parameters menu
will appear and the Grid Limiter Function will be the first tab. You may still need to program other tabs,
but this Grid Limiter tab plays an important role in battery behavior. The programmed levels are user
specific, so think carefully when programming this menu relative to the specific job site and grid policy.
80A
51V
0 Hours
5%
48V
50.5V
10%
15%
54.4V
54.4V
54.4V
5%
20%
25%
49V
51.4V
51.8V

Rev A 08-28-21
Fortress Power - Sol-Ark LFP Legacy Series Inverter Guide
Grid Sell –Select to sell back to the grid when
the batteries are full.
Limited to Home –Select when not allowed
to backfeed the grid or when utility solar
buyback rates is horrible. Typically requires
200A SolArk CTs around the main grid feed.
Limited to Load –Select when offgrid.
Time-of-use –Almost always select this
feature, even when off-grid. It is useful to
optimize battery use conditions such as
grid/generator charging.
Charge Column –Checking the box will force
a grid charge.
Batt V Column –If there is a surplus amount of solar on site, solar will always charge the battery full to 54.4V
before selling back to the grid. But if the battery falls below this voltage and grid power is available, the battery will
switch over to grid power. The suggested settings help the battery drain at night for efficient solar operation, while
keeping enough reserve capacity for power outages. These numbers could be set to 54.4V to always keep the
battery at 100% full.
Next Steps:
Before leaving site, verify that all batteries are working. This can be
simply done by looking at the LCD screen and confirming amperage is
flowing in or out of each battery. Apply a charge current and confirm
the state-of-charge light is blinking on each battery.
The best way to translate voltage into % SoC is to remove any
load from the battery before measuring battery voltage.
Congratulations on reading the entire
Fortress / Sol-Ark integration guide.
Don’t forget to join our Discord chat
group.
A blinking State of Charge
Indicator Light confirms that the
battery is charging.
Suggested Grid-Tie Parameters
9000
3:00AM
M
5:00AM
M
9:00AM
3:00PM
7:00PM
M
9:00PM
3kW
3kW
9kW
3kW
9kW
3kW
51.8V
51.4V
53.7V
54.4V
52.8V
52.3V
✓