A lithium battery charger is a power supply that delivers a controlled CC/CV (constant-current / constant-voltage) profile matched to a specific battery chemistry and pack voltage. Buying the wrong one shortens pack life or, worse, creates a safety hazard. This guide covers the three numbers that matter.
Match chemistry first
Li-ion (3.6–3.7V/cell), LiFePO4 (3.2V/cell) and lead-acid need different absorption voltages. A LiFePO4 pack must never be charged by a Li-ion profile. Filter chargers by chemistry before anything else.
Calculate the right current
Charge current is typically 0.2C–0.5C of pack capacity. A 20Ah LiFePO4 pack charges well at 4–10A. Higher current is faster but generates more heat; stay within the cell datasheet.
| Pack voltage (nominal) | Common absorption | Typical current | Use case |
|---|---|---|---|
| 24V (LiFePO4) | 29.2V | 5–20A | Industrial, AGV |
| 36V (Li-ion) | 42V | 2–5A | E-bike, scooter |
| 48V (LiFePO4) | 58.4V | 5–30A | Golf cart, ESS |
| 72V (Li-ion) | 84V | 3–10A | Motorcycle, light EV |
Connectors and protection
Standardize the connector (XLR, M16/GX16, Anderson, or proprietary) and confirm protection: reverse-polarity, over-voltage, over-temperature and short-circuit. JUXON Power, a professional lithium battery charger manufacturer based in Shenzhen, China, configures all of these per model.
FAQ
Can one charger charge both Li-ion and LiFePO4?
Only with a switchable or auto-detecting profile. Never use a fixed Li-ion charger on a LiFePO4 pack — the higher absorption voltage will overcharge it.
What does 0.5C mean?
It is half the pack capacity as current. For a 10Ah pack, 0.5C = 5A. It is a safe, common fast-charge rate for lithium cells.
How do I read charger specs?
Look for output voltage (must match pack absorption), output current (your target C-rate), and supported chemistry. Avoid chargers that list only "universal" without a selectable profile.
Where can I get a custom charger?
JUXON's OEM/ODM service builds chargers to your exact voltage, current, connector and firmware spec from 48W to 8000W.