EG4 Battery Power Wiring Diagrams

This document provides wiring diagrams and system configuration details for EG4 batteries, designed for paralleling with EG4 Hybrid and Off-Grid inverters.

Key Information for EG4 Battery Paralleling

• 280 AH Outdoor All Weather WallMount Battery: Refer to Section 8.1 in the MANUAL.
• 280 AH Indoor WallMount Battery: Refer to Section 8.7 in the QUICK-START GUIDE.
• 100 AH WallMount Indoor Battery: Refer to Section 8 of USER MANUAL.
• 100 AH Server Rack Batteries: Refer to sections 7.3 (48V), 7.1 (12/24V) of MANUAL.

Drawings Table of Contents

Page 2

Table #1: UL9540 Approved EG4 ESS Inverter-Battery Combinations

Table #2: Recommended Minimum Battery/Inverter Ratios for EG4 ESS Systems

Wiring Diagrams

The following sections detail various wiring configurations:

3) 1 x EG4 Hybrid or Off-Grid Inverter with 1-3 280 AH EG4 WallMount Batteries (Indoor or Outdoor)

Notes:

• The WallMount battery ships with one set of 4 cables (2 red, 2 black) for one battery to one inverter.
• For each additional battery, a paralleling kit must be purchased separately.
• Custom cables can be ordered or made using Degson connectors and crimp tools if included cables are insufficient.
• A maximum voltage drop of 2% is recommended for battery-to-battery and battery-to-inverter cabling. Single sets of paralleling cables should not exceed 20'. Dual cables can decrease voltage drop.

Important Note:

• The recommended minimum ratio of 280 AH WallMount batteries to 18kPV inverters is 1.5:1.
• A single battery with an 18kPV inverter may perform close to, but not at, its full rated capacity. The 18kPV can handle 230A continuous, while a 280AH battery is limited to 200A max (180A recommended continuous).
• With one battery, the 18kPV inverter's output is limited to 10,240 Watts when powering loads or selling back to the grid from battery alone.
• For single battery/inverter setups, setting max charge/discharge to 180 Amps is recommended, or consider using two batteries.

Overcurrent Protection: EG4 280 AH WallMount Batteries have internal bus bars rated to 600 Amps and internal breakers rated to 200 Amps per battery. The EG4 18kPV inverter has two 200 Amp Battery Breakers per positive terminal. No additional overcurrent protection is needed for paralleling up to 6 batteries and 2 inverters. Use 2/0 battery cables and ensure 2 runs of cables to each positive and negative inverter terminal.

4) One EG4 Hybrid or Off-Grid Inverter with 4-6 280 AH EG4 WallMount Batteries (Indoor or Outdoor)

Notes:

• The WallMount battery ships with one set of 4 cables (2 red, 2 black) for one battery to one inverter.
• For more than one battery per inverter, a paralleling kit must be purchased separately.
• Custom cables can be ordered or made using Degson connectors and crimp tools if included cables are insufficient.
• A maximum voltage drop of 2% is recommended for battery-to-battery and battery-to-inverter cabling.

Cable Overcurrent Protection: EG4 280 AH WallMount Batteries have internal paralleling bus bars rated to 600 Amps and internal breakers rated to 200 Amps per battery. The EG4 18kPV inverter also has two 200 Amp Battery Breakers per positive battery terminal. No additional overcurrent protection is needed when paralleling up to 6 batteries and up to 3 inverters, following the specified sequence. Use 2/0 battery cables and ensure 2 runs of cables to each positive and negative inverter terminal. Do not separate batteries more than necessary.

Battery Spacing and Custom Cables: If batteries need to be farther apart than paralleling kits allow, custom cables using Degson connectors and crimp tools are required. For cable runs longer than 15', adding a second custom paralleling cable can help maintain acceptable voltage drop. Battery-to-inverter distance should not exceed 20' of dual cable. 280 AH batteries require 2/0 Degson connectors.

5) 1-3 x EG4 Hybrid or Off-Grid Inverters with 4-6 x 280 AH EG4 WallMount Batteries (Indoor or Outdoor)

Placement of Inverter & Battery Connections in Multi-Inverter Systems:

• Follow a logical order for maximum performance, minimum voltage drop, and minimum current on each cable.
• Single or dual inverter systems should not be placed on the "end" batteries in the parallel stack.
• For dual or triple inverter systems, inverters may be placed on every other battery.
• Refer to the next page for options for "Disable Battery Sharing" if batteries cannot be equally spaced and co-located.

Battery Spacing and Custom Cables: If batteries need to be separated farther apart than paralleling kits allow, or via "Disable Battery Sharing," custom cables using Degson connectors and crimp tools are required. For cable runs longer than 15', adding a second custom paralleling cable can help maintain acceptable voltage drop. Battery-to-inverter distance should not exceed 20' of dual cable. 280 AH batteries require 2/0 Degson connectors.

Cable Overcurrent Protection: EG4 280 AH WallMount Batteries have internal paralleling bus bars rated to 600 Amps and internal breakers rated to 200 Amps per battery. The EG4 18kPV inverter also has two 200 Amp Battery Breakers per positive battery terminal. No additional overcurrent protection is needed when paralleling up to 6 batteries and up to 3 inverters, following the specified sequence. Use 2/0 battery cables and ensure 2 runs of cables to each positive and negative inverter terminal. Do not separate batteries more than necessary.

Note on Battery Separation: If batteries need to be separated by distances larger than parallel kit cables accommodate, consider providing 2 or 3 equal sets of batteries to paralleled inverters using the "Disable Battery Sharing" setting.

6) Separating Batteries on Paralleled Inverters using the "Disable Battery Sharing" Setting

For multiple inverter systems with paralleled inverters, equal sets of batteries can be split between the inverters to avoid long parallel cable runs by using the “Disable Battery Sharing” setting. The inverters will keep the independent battery sets at roughly equal State of Charge (SOC). This configuration can work with 2 equal sets on 2 inverters or 3 equal sets on 3 inverters.

Example: 2 Paralleled Inverters and 4x280Ah Outdoor WallMount Batteries using "Disable Battery Sharing"

Note: Battery Parallel Cabling Kits must be ordered separately for each additional battery.

7) 1 or 2 EG4 Hybrid or Off-Grid Inverters with Server Rack Batteries - 1-2 Racks

Notes:

• The 18kPV inverter has a maximum charge and discharge rate of 250 Amps and a continuous rating of 230 Amps.
• A minimum of 3 server rack, 100 AH batteries are recommended per 18kPV.
• Built-in battery and inverter overcurrent protection, coupled with the battery BMS, provides a good level of protection.
• The inverter has two 200 Amp Battery Breakers per positive terminal; each battery has a 100 Amp Breaker.
• Class T fuses can be added for full protection of the cable run. Consult your AHJ (Authority Having Jurisdiction) for exact requirements.
• Each positive terminal requires a minimum of 2/0 cable; use 4/0 cable if using a single positive cable.
• Protect all cable in metallic conduit or raceways. Exposed cables are unsafe and violate the NEC code.

8) 1 EG4 Hybrid or Off-Grid Inverter with Server Rack Batteries - 3 or more Racks

Notes:

• The 18kPV inverter has a max charge and discharge rate of 250 Amps and a continuous rating of 230 Amps.
• Fuse protection on a bus bar ensures overcurrent protection for possible shorts between racks and rack cabling.
• Class T fuses are required to protect battery cabling per NEC Code.
• For 1 inverter and 3 server rack systems: Recommend installing Class T Fuse Blocks and Fuses. Use 2 runs of 2/0 cable between bus bar and inverter with individual 200 Amp fuses per run (e.g., Blue Seas Systems 5007100 and Littelfuse JLLN200, or equivalent).
• For 1 inverter and 3 server rack systems: Recommend 2/0 cable between rack bus bars and positive bus bars with 200 Amp fuses. This prevents cascading nuisance tripping if one fuse blows.
• Use 600 Amp Rated Positive and Negative Bus Bars (e.g., Blue Seas Systems 2104 PowerBar, 600A, 4x3/8"-16 Studs, or equivalent).
• Each battery is protected by a 100 A DC Breaker and a 100 Amp BMS that detects short circuits.
• Protect all cable in metallic conduit or raceways. Exposed cables are unsafe and violate the NEC code.

9) Multiple EG4 Hybrid or Off-Grid Inverters with Server Rack Batteries - 3 or more Racks

Notes:

• Each 18kPV inverter has a max charge and discharge rate of 250 Amps and a continuous rating of 230 Amps.
• Fuse protection on a bus bar ensures overcurrent protection for possible shorts between racks and rack cabling.
• Class T fuses are required to protect battery cabling per NEC Code.
• For 1 inverter and 3 server rack systems: Install Class T Fuse Blocks and Fuses. Recommend using 2 runs of 2/0 cable between bus bar and inverter with individual 200 Amp fuses per run (e.g., Blue Seas Systems 5007100 and Littelfuse JLLN200, or equivalent).
• For 2 inverter and 4 server rack systems: Install Class T Fuse Blocks and Fuses. Recommend 2/0 cable between rack bus bars and positive bus bars with 200A fuses. This will prevent cascading nuisance tripping if one fuse blows.
• Use 600 Amp Rated Positive and Negative Bus Bars (e.g., Blue Seas Systems 2104 PowerBar, 600A, 4x3/8"-16 Studs, or equivalent).
• Each battery is protected by a 100 A DC Breaker and a 100 Amp BMS that detects short circuits.
• Protect all cable in metallic conduit or raceways. Exposed cables are unsafe and violate the NEC code.

Tables

Table #1: Minimum Recommended Battery to Inverter Ratios for EG4 ESS Systems

Note: This chart shows the minimum number of EG4 batteries for any given EG4 Inverter to supply its full rated continuous and surge power. Note that even if the ESS chart indicates a lesser number of batteries is UL approved, this does not guarantee the inverter won't be throttled to a lower output. For example, using a single 280 AH battery with the FlexBoss21 or 18kPV will result in the inverter's 50 Amp rating being downgraded to 43 Amps. Consult your sales rep for the EG4 Battery and Inverter Sizing spreadsheet.

Note: For ESS System Model Numbers for all combinations of EG4 Inverters and Batteries, see the website under Technical Support Bulletins for the document “EG4 ESS Model Number Explanation".

Table #2: EG4® ESS Inverter Battery Combinations with ETL Conforming to UL9540

*Batteries must be mounted in server rack to comply with UL 9540

Certificates are available in the ESS Systems descriptions at eg4electronics.com