Sol-Ark 12K

Sol-Ark sits at the expensive end of the DIY range and buys two things with the money: a published closed-loop battery list, and a 63 volt upper limit that leaves room above a 58.4 volt absorption setpoint. That headroom sounds academic until a pack finishes balancing on a cold day and the terminal voltage climbs past where a 60 volt inverter would fault.

Published figures

Continuous output

9,000 W

Surge output

12,000 W

Battery voltage window

42 to 63 V

Max charge current

175 A

Battery comms

CAN, RS485

Output

120/240 V split phase

Grid interactive

Yes

PV input

13,000 W, 500 Voc max

What this inverter will and will not do

• It works alongside the utility, which means an interconnection agreement, a permit, and an inspection in most jurisdictions. Budget months, not weeks, for that process.
• Output is 120/240 V split phase from one box, so standard household 240 V loads run directly.
• Battery communication runs over CAN, RS485, and closed loop still depends on both sides agreeing on a message format rather than only on a bus standard.

Sizing a battery bank for it

This inverter delivers up to 175 amps of charge current, and that figure, not your daily energy use, sets the minimum pack count. Every battery below is shown at the smallest bank that can absorb the full charge rate.

Fuse and cable for the battery run

Running flat out this inverter pulls about 188 amps at 48 volts, and a surge takes it to roughly 250 amps. Size the protection for the peak, not the average: a 250 amp Class T fuse at the battery positive terminal and 4/0 AWG cable on the battery run. Class T rather than a standard fuse because a 48 volt lithium bank can deliver enough short circuit current to arc across a fuse that lacks the interrupt rating. Confirm the sizing against your installation manual, which accounts for run length and ambient temperature.

Communication

Manufacturer documentation names Fortress eVault Max 18.5kWh, Pytes E-BOX 48100R, HomeGrid Stack’d 48V 9.6kWh for closed-loop operation. Any battery not on that list runs open loop until a document says otherwise.

Where the figures come from

Manufacturer documents: Sol-Ark resources and manuals. Figures here should be read against the revision that covers your serial number, because manufacturers revise specifications without changing the model name.

Questions people actually ask

Worth reading before you install

• How many batteries this inverter actually needs
• Split phase or single phase, and what it costs to get wrong
• Off grid or hybrid, and what each one will not do
• Cable sizing for the battery run