Charge Acceptance
What Is Charge Acceptance?
Charge acceptance measures how quickly a battery can absorb charge current at a given voltage and state of charge. It is the current (in amperes) a partially discharged battery accepts when connected to a charging source at a fixed voltage. Higher charge acceptance = faster recharge.
This is the critical differentiator between SLI, EFB, and AGM batteries in modern vehicles.
Test Method — DCA (Dynamic Charge Acceptance) per EN 50342-6
- Battery is discharged to 80% State of Charge (SoC)
- A charging voltage of 14.0V is applied
- Current is measured at specified time intervals
- DCA is reported as I_charge / C20 ratio
| Battery Type | Typical DCA Ratio | Recovery Time Between Start-Stop Events |
|---|---|---|
| SLI | 1.0 (baseline) | 60-120 seconds |
| EFB | 1.5-2.0x SLI | 30-60 seconds |
| AGM | 2.0-3.0x SLI | 15-30 seconds |
Why Charge Acceptance Matters
In start-stop vehicles, the engine may restart 20-50 times per trip. Between each stop, the battery has only 30-60 seconds to recharge before the next restart. If charge acceptance is too low:
- Battery never reaches full charge → chronic partial state of charge (PSoC)
- Sulfate crystals accumulate on negative plates → sulfation
- Capacity fades → battery fails within 12-18 months instead of 3-5 years
This is why AGM is mandatory for aggressive start-stop systems.
Chengguang Charge Acceptance
| Technology | Charge Acceptance | Suitable For Start-Stop |
|---|---|---|
| SLI | Baseline | :material-close: No |
| EFB | 1.5-2x SLI | :material-check: Entry level |
| AGM | 2-3x SLI | :material-check: Full |
Contact Chengguang for AGM/EFB charge acceptance specifications for your OEM order.
Author: Chengguang Power Tech Engineering Team | Reference: EN 50342-6