Testing ev battery packs & modules to LV 123 / LV 148
OEM and tier-one battery engineering teams live inside a voltage window, and LV 123 / LV 148 is what defines its edges. With cells, modules and full high-voltage packs on 40–1500 VDC, high current, the job is capacity, cycle life and behaviour at the edges of the voltage window — at the top of the band, at the bottom, and through every transition between them. Voltage-class bands is the whole test; 400 Hz never enters it. That calls for bidirectional DC supply spanning 0–800 V with ripple superposition and millisecond profile sequencing for HV work; 0–70 V with programmable milliohm output impedance for 48 V board-net work.
What you are testing
- Device under test
- cells, modules and full high-voltage packs
- Bus
- 40–1500 VDC, high current
- Who buys this
- OEM and tier-one battery engineering teams
What LV 123 / LV 148 does not cover
- 400 Hz
- harmonic immunity
- grid conformance
If your programme needs those, they come from a different standard and often different hardware.
The limits this test has to reproduce
A pack test spends most of its life inside the unlimited operating band. What decides the rig is the current at the top of the window and the behaviour at the edges.
| Parameter | Value | Clause |
|---|---|---|
| HV_1 unlimited operating | 90–190 V | LV123 voltage classes |
| HV_2a unlimited operating | 170–340 V | LV123 voltage classes |
| HV_2b unlimited operating | 250–450 V | LV123 voltage classes |
| HV_3 unlimited operating | 520–750 V (circuit limit 800 V pk) | LV123 voltage classes |
| Overvoltage pulse slew | max 20 V/ms | LV123 §10.4 |
| LV148 unrestricted operating | 36–52 V | VDA 320 |
| LV148 transient overvoltage | 70 V for 40 ms | E48-02 |
| LV148 long-term overvoltage | 60 V for 60 min | VDA 320 |
| LV148 source impedance | 10–100 mΩ | VDA 320 |
The clauses ev-battery programmes actually face, as published in LV 123 / LV 148. See every limit in LV 123 / LV 148. Certification work should be run against the published standard.
What decides the rig here
The requirements that separate a system that can run this programme from one that only meets the headline numbers.
Current, not voltage, sets the architecture
Pack-level discharge current drives busbar design, contact resistance and sense-lead discipline long before the voltage rating matters.
Regeneration is an economic decision
Dissipating pack discharge as heat is paid for twice — once at the meter and again in cooling load.
Channel count decides your calendar
Qualification throughput is a function of parallel channels, not system power. This is the number that slips schedules.
Other standards this DUT usually faces
Further reading on LV 123 / LV 148
- AQG 324 and SiC Modules: When the Named Guideline Does Not Cover Your Device
- The Battery Tester Voltage Window: Bought for 1500 V, Caught Out at 36 V
- High-Current Battery Testing: The Joint Fails Before the 8,000A Supply
- ISO 16750-2: The Code Letter Is the Specification, Not the Voltage
- 48 V and 800 V Answer to Different Documents, Not Just Different Voltages
- LV 123 and LV 148: Testing Across the Voltage Window, Not Just at Nominal
Send us the clauses you have to satisfy
We will come back with the source and load capability that covers them — and tell you plainly if something in your spec needs hardware we would not supply.
Talk to an engineer