Fox ESS 4-Way HV Battery Junction Box | HV-Junction Box-50 | IP65

Description

The Fox ESS HV Junction Box (HV-Junction Box-50) is a dedicated 4-way DC combiner for Fox ESS high-voltage battery systems. It connects up to four battery stacks in parallel and brings them together on one load output to a single compatible Fox ESS inverter, so your storage can grow well beyond a single battery tower.

Rated for 500 V nominal, 50 A continuous and 65 A peak for 60 seconds, it is housed in an IP65-rated, wall-mounted enclosure approved for indoor or outdoor installation and uses natural cooling, so no fans are needed. It is the clean, neat way to scale a Fox ESS storage system up to 41.4 kWh for larger homes and light-commercial sites.

4

Battery inputs

1

Load output to inverter

500 V

Nominal voltage

50 A

Continuous current (65 A peak, 60 s)

IP65

Indoor and outdoor rated

41.4 kWh

Maximum scalable storage

Safety: high-voltage DC equipment

This unit handles high-voltage DC from battery stacks. Installation and wiring must be carried out by a competent, qualified electrician experienced with high-voltage battery systems, in line with BS 7671 and the Fox ESS installation manuals. Isolate all DC and battery circuits before any work, observe correct polarity, and complete all earthing connections.

Compatibility: confirm before you order

The manufacturer lists compatible inverters as the K, H1 (G2), H3, H3 PRO and US series. The junction box is specified for high-voltage Fox ESS systems at 500 V nominal. Always confirm your exact battery and inverter pairing against Fox ESS documentation, or contact our team, before purchasing.

Check dimensions when planning wall space

Fox ESS datasheet revisions list different physical data for this model. The current revision shows 223 x 246 x 89 mm and 2.6 kg; an earlier revision showed 186 x 170 x 78 mm and 4.5 kg, and a lower maximum capacity of 40 kWh. Allow for the larger footprint when planning the installation and check the delivered unit against the label and manual.

How it fits into the system

Up to four Fox ESS high-voltage battery stacks connect to the four battery inputs. The single load output then runs to the battery port of the compatible Fox ESS inverter.

Key features

4-way battery parallel

Four battery inputs let you combine up to four high-voltage battery stacks into one bank, ideal for scalable storage as your energy needs grow.

Single load output

One load output keeps the connection to the inverter simple and tidy, with a consolidated DC run rather than multiple battery feeds.

50 A continuous, 65 A peak

Rated for 50 A continuous current and 65 A for 60 seconds at 500 V nominal, supporting demanding evening loads, EV charging and heat pumps.

IP65 weather protection

The IP65 enclosure is dust-tight and protected against water jets, and the unit is specified for indoor and outdoor installation.

Wall-mounted, naturally cooled

Wall-mounted design with natural cooling means no fans, no extra power draw for ventilation and quiet operation.

Wide operating range

Operates from -20 to 70 C with an optimum of 15 to 30 C, and tolerates 5 to 95 percent humidity (non-condensing), at altitudes up to 2000 m.

Typical applications

Expanding Fox ESS battery banks where more than one high-voltage battery stack needs to feed a single inverter. Larger residential systems with high evening demand, electric vehicle charging and heat pumps. Light-commercial installations such as small businesses, workshops, offices and community buildings that need scalable storage.

Technical specification

General

Model

HV-Junction Box-50

Product type

High-voltage battery junction box (4-way parallel combiner)

Compatible inverters (PCS)

K, H1 (G2), H3, H3 PRO, US series

System parallel description

Supports 4 battery inputs and 1 load output

Scalable storage

Up to 41.4 kWh

Electrical

Nominal voltage

500 V

Maximum continuous current

50 A

Peak current

65 A for 60 seconds

Environmental

Operating temperature

-20 to 70 C

Optimum operating temperature

15 to 30 C

Storage temperature

-20 to 55 C

Humidity

5 to 95 percent (non-condensing)

Altitude

Up to 2000 m

Ingress protection

IP65

Cooling method

Natural cooling

Installation location

Indoor or outdoor

Mechanical and compliance

Installation method

Wall-mounted

Dimensions (W x H x D)

223 x 246 x 89 mm

Weight

2.6 kg

Environmental compliance

RoHS, REACH

Frequently asked questions

How many batteries can the HV Junction Box connect?

It has four battery inputs and one load output, so up to four Fox ESS high-voltage battery stacks can be connected in parallel to a single compatible inverter.

Which Fox ESS inverters is it compatible with?

The manufacturer datasheet lists the K, H1 (G2), H3, H3 PRO and US series. Check your exact battery and inverter combination against Fox ESS documentation before ordering, or ask our team to confirm it for you.

Can I install it outdoors?

Yes. The enclosure is IP65 rated and specified for indoor or outdoor installation, with an operating range of -20 to 70 C. Performance is best at an optimum 15 to 30 C, and humidity must be non-condensing, so a sheltered, well-chosen position is recommended.

What are the current and voltage limits?

The unit is rated at 500 V nominal, 50 A continuous and 65 A peak for 60 seconds. Your installer should check that the combined battery current for your system stays within these ratings.

Who should install it?

A qualified electrician experienced with high-voltage battery systems should install and wire it, working to BS 7671 and the Fox ESS manuals, with all DC and battery circuits safely isolated first.

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