Battery Storage System

A power storage system used in offices, factories and other applications as well as at home. Introducing Panasonic relays that support the stabilization of renewable energy output and high charge / discharge efficiency.

Applications

Battery Storage System

Inverter

AC plug

Load

Storage battery

Storage battery

LF-G HE-S HE PV
LF-G HE-S HE PV
(LF-G/HE PV: 1a 22 A-90 A 250 V AC)
(HE-S: 2a/2a1b 40 A 277 V AC)
EP HE-V AQ-A
SSR
EP HE-Vリレー AQ-A
(EP: 1a 20 A 1,000 V DC*1)
(HE-V: 2a 20 A 1,000 V DC*2)
(AQ-A: 1a 10 A 600 V DC)
*1 1,000 V DC is Max. switching voltage. The rating is 400 V DC.
*2 1,000 V DC is Max. switching voltage when each 1 Form A contact is connected in series. The rating is 800 V DC.
PhotoMOS
PhotoMOS
Max. load voltage 1,500 V are available.
For available types, please contact our sales representative.
EP AQ-A
SSR
EP AQ-A
(EP: 1a 20 A, 80 A 1,000 V DC*)
(AQ-A: 1a 10 A 600 V DC)
* 1,000 V DC is Max. switching voltage.
The rating is 400 V DC.

Safety cutoff (AC and DC)

For Safety Cutoff on the AC side
Relays are used for safety cutoff on the grid (power network). The relay must cutoff the circuit to prevent abnormal currents that occur from affecting the commercial power supply. Power relays are required as safety measures to protect the power supply system.
For Safety Cutoff on the DC Side
Power relays are required as safety measures in the event of a defect in or malfunction of the battery or system.

Charge and discharge

For Charge and Discharge
AQ-A SSR (PhotoMOS) is used to switch charge and discharge. We recommend solid state relays for applications where there will be frequent ON/OFF switching.
Charge control
Discharge control
Storage battery
1
Regular operation
Turn ON both solid state relays for charge and discharge control.
Current flows in both directions.
2
Over-charge prevention
In order to prevent over charging, the solid state relay on the charge control side turns OFF.
On the discharge side, current will flow because there is a diode.
3
Over-discharge prevention
In order to prevent over discharging, the solid state relay on the discharge control side turns OFF.
On the charge side, current will flow because there is a diode.
Charge and discharge control is possible by effectively utilizing the internal diodes of the solid state relay.
Equivalence circuit of output side
*If you want to use charge and discharge control by internal diodes of the solid state relay, please contact our sales representative.
(Maximum switching capacity differs from output section.)
Recommended
relay

Preventing inrush current

For preventing an inrush current into capacitors when charging (pre-charge circuit)
AQ-A SSR (PhotoMOS), HE-V relay, and 10A and 20A types of EP relays are used for preventing an inrush current into capacitors when charging. We recommend solid state relays for miniaturization and HE-V relay and 10A and 20A types of EP relays for high voltages.

Main relay
(For DC safety cutoff)

Inverter

Using high-capacity capacitor.
Possibility of inrush current

Inrush current prevention relay
(pre-charge relay)


During device startup, the inrush current prevention relay turns ON and the main relay turns ON after the capacitor is charged.
Effective for protection against inrush currents that occur when charging the capacitor.
Recommended
relay

*1: 1,000 V DC is Max. switching voltage. The rating is 400 V DC.

*2: 1,000 V DC is Max. switching voltage when each 1 Form A contact is connected in series. The rating is 800 V DC.

Insulation detection

For Insulation Detection
PhotoMOS are used for monitoring storage battery units for insulation deterioration
If the insulation in a unit deteriorates, a ground-fault current passes when the relay is turned on, and a sensor detects the current.
High load voltage type PhotoMOS are ideal for use with storage batteries, which carry high voltage.

Alarm signal output
<abnormal case>

Current sensor

Storage battery

Current sensor

Section with deteriorated insulation

Inside of a storage battery unit

If insulation is deteriorated in a section, a current passes when the relay is turned on.

(When insulation of high voltage area and chassis is deteriorated)
1. PhotoMOS is turned on.
2. The current sensor detects a ground-fault current.
3. An alarm signal is output.

Current

Recommended
relay

Max. load voltage 1,500 V are available.
For available types, please contact our sales representative.

Battery monitoring

For Battery Monitoring
PhotoMOS are used in a circuit for monitoring charging voltages of a battery cell group.
Compact PhotoMOS capable of frequent switching are ideal for this type of use.
Use of the relays allows for insulation from high voltage areas.

When charging the capacitor

[Battery cell side]

[Measurement
side]

1. PhotoMOS on the battery cell side are turned on.
2. The capacitor is charged.

When measure

[Battery cell side]

[Measurement
side]

1. PhotoMOS on the battery cell side are turned off.
2. PhotoMOS on the measurement side are turned on.
3. The voltage of capacitor (= voltage of battery cell group) is measured.
Recommended
relay

Max. load voltage 1,500 V are available. For available types, please contact our sales representative.

Recommended Materials

SERIES CATALOG Title Language File size Update
エネルギーマネジメント向け商品のご提案 JP 12.5MB October 1, 2025
Products for Energy Management EN 12.2MB October 1, 2025
面向能源管理的商品提案 CN-Simplified 3.8MB February 28, 2025