Smart Sealed Lead Acid Battery Charger Kit – CK0193
Smart Sealed Lead Acid (SLA) Battery Charger Kit with Current Limiting. The charger uses a two step process for charging SLA batteries – a current limited ‘fast’ mode followed by a constant voltage ‘float’ mode. An onboard LED indicates when the charger is in ‘fast’ mode. When the LED goes out the battery is charged and the charger has switched to ‘float’ mode.
The best way to charge a Sealed Lead Acid (SLA) battery is with a current limited voltage regulator, allowing fast charging while limiting heat buildup and gassing.
SLA batteries are made up of 2V (nominal) cells. Therefore a 12V battery has 6 cells.
The following parameters were used for this charger:
1. The charging current should be approximately 0.1 times the battery capacity. So, a 10Ah battery should be charged with a 1A current (10 x 0.1 = 1). This helps to ensure battery life.
2. The charging voltage is 2.45V per cell = 14.7V 3. Float charging voltage is 2.275V per cell = 13.65V
Power Supply Specification:
The minimum DC input voltage is set by the charging voltage (14.7) plus 3V regulator voltage drop plus the voltage drop (0.7) across the input and output diodes. This works out at 19.1V (14.7 + 3.0 + 0.7 + 0.7).
A 19VDC supply with a current rating of at least 2A should work fine. This is a common power supply used with many laptop/notebook computers and will be readily available from your local computer store or even your local computer swap meet.
Electronic Kit – Soldering required.