Charging a Lead-acid battery with CC/CV

Hello,

If you want to charge a lead-acid battery using constant voltage/constant current, usuallay a three phase situation. First phase being constant current, until V(battery) reaches V(bulk), and then constant voltage at V(bulk) until current drops to I(min). The final stage being a trickle charge where the constant voltage is lowered V(trickle). This is mostly used for fast chargers or what not.

My question is, when your applying a constant current to the battery, does it matter what voltage your applying to the battery? If the battery is dead, the constant current will bring the voltage of the battery up, but what voltage do you apply to the battery during consatnt current?

I'm new to battery charging, so any help would be appreciated. Thanks


/Baz1

The voltage isn't important during the constant current phase. However, if the applied voltage tries to go much above the normal battery voltage, that would be a sign of a defective battery (open cell, etc).

i guess this is my question... if charging a battery, can you have constant current and constant voltage at the same time? or do you have to switch the constant voltage part of the ciruit off while delivering constant current, and then shut the constant current circuit off while delivering constant voltage?

I'm trying to design a SLA smart battery charger, but i'm confused with this aspect.


/Baz

The easyer way is to apply Constant Voltage with current Limit.
Lead acid needs only constant voltage, it is sensitive to voltage levels.
You may need to limit the current for smaller batteries just to keep it withing safe limits in order to avoid drying or overheating of the battery.

P.