dear all

i am charging lead acid battery using full bridge topology, when i check the output current with resistive load (8A) the waveform is good i.e it is in continues and having ripple current of 2A pk-pk.

next i connected the battery, the current waveform is good upto 3 amps, beyond 3 amps the output current is going to pk pk 16A. the waveform is not good it is going to 1amp to 16 amp.

i did not understand why the system is behaing like this.

can any body explain this problem.






thanks and regards
ramesh

 

As you draw more current the filter capacitor does not have enough time to charge to the peak voltage and thus you see more ripple voltage. Use a larger filter capacitor.

 

As you draw more current the filter capacitor does not have enough time to charge to the peak voltage and thus you see more ripple voltage. Use a larger filter capacitor.

dear mik3 thanks for your reply

see my problem is not with the voltage, my chraging voltage is almost constant with pk-pk 2V, but battery charge current is going from 1A to 16A periodically.

here pk-pk is almost 16A mean/average of this 7A.

any suggestions.

 

Can you explain the problem better?

Note that if the voltage is constant, the charging current will decrease with time. A battery is not like a resistor but like a capacitor.

 

电池是非电阻性负载，充电时要用“定压、限流”

battery is Non-resistive loadl, while charging should use "Fixed voltage, current-limiting"