Power Supplies and Battery Chargers by E.D.S. | Lithium Ion Battery Chargers

E.D.S. offers a fully controlled lithium ion / lithium polymer charger designed to properly return capacity to a lithium ion battery without fear of overcharge. Each charger is equipped with an LED, which indicates charge status. These linear transformer based models can be designed as either a 120V, 60Hz US model or 230V overseas model.

This charger has three distinct states throughout the charge of the battery. When first connected to the battery, the charger checks the battery voltage and starts in either State 1 or State 2.

State 1
If the battery voltage is below the precharge threshold (</=3VDC/cell), the circuit uses a precharge current to condition the battery until it reaches approximately 3.2VDC/cell at which time it will go into State 2. This conditioning charge rate is set at approximately 10% of the full load regulation current. The red LED is fully illuminated while in stage 1.

State 2
The circuit then regulates the current at the full load rate while the battery-pack voltage is less than the regulation voltage of 4.2VDC/cell. The red LED is fully illuminated while in stage 2. The red LED is fully illuminated in this stage.

State 3
Upon reaching the regulation voltage (4.2VDC/cell), the circuit tapers the current back down until it turns off maintaining the battery at 4.2V/cell. The LED goes out when the charger reaches stage 3. The LED goes out in this stage.

(printable PDF specification sheet)

Economical Linear Models
# Cells	1 cell	1 cell	2 cell	2 cell
Charge Voltage	4.2	4.2	8.4	8.4
Charge Current	200 mA	500 mA	200 mA	500 mA
Test Data	see data	see data	see data	see data