Illustrative equipment photography, not this model.
Fortress Power battery
The generation before the eVault Max, still widely installed and still sold as stock clears. Its 100 amp charge limit is the practical difference from the Max.
Published figures
Usable capacity
18.5 kWh
Capacity
360 Ah
Voltage window
44.8 to 58.4 V
Max charge current
100 A
Max discharge current
100 A
Comms
CAN, RS485
Form factor
Floor standing
Units in parallel
10
Source status: Provisional figure Typical street price $5,500 to $7,000. Charge and discharge limits are per unit. Wiring packs in parallel raises both.
How many you need, by inverter
One pack accepts 100 amps. An inverter that can deliver more than that needs more than one, or the charge rate capped in settings. Both are valid, and the second one costs you charging speed on the short days when you need it most.
Manufacturer documentation names Sol-Ark 12K, Schneider XW Pro 6848 for closed-loop operation with this pack.
Where the figures come from
Manufacturer documents: Fortress Power document library. Figures here should be read against the revision that covers your serial number, because manufacturers revise specifications without changing the model name.
Where to buy the Fortress eVault 18.5kWh
Listings for the Fortress eVault 18.5kWh plus the rack hardware and cabling a clean install needs.
Affiliate links. As an Amazon Associate this site earns from qualifying purchases, at no extra cost to you. Prices and stock change often, and a listing appearing here is not a statement that the pairing above is approved.
Questions people actually ask
How many Fortress eVault 18.5kWh packs do I need?
One pack accepts 100 amps and holds 18.5 kWh. Match the pack count to your inverter’s charge current first, then check the energy. A Sol-Ark 15K at 275 amps would take 3 of them to charge at full rate.
Does the Fortress eVault 18.5kWh do closed loop communication?
It publishes CAN, RS485. Manufacturer documentation names Sol-Ark 12K, Schneider XW Pro 6848 specifically.
How many can I wire in parallel?
The published limit is 10 units.
Which inverters pair cleanly with the Fortress eVault 18.5kWh?
None of the inverters tracked here clear all four checks with this pack. Most land on unverified because nobody has published the comms or surge figure, which is a gap rather than a fault.
