refreshing Ni- cad battery

[Rolf]

Hi members I have two ?s on Nicads // they seem to hv memory // so ihave heard they need to be fully
discharged sometimes before recharging // if a person dischages a 5 volt nicad fully,,,, what voltage will it read
//// also is there a recomended simple circuit to do this ?????? Thankyou

 

[Bluejets]

Do not discharge below 0.8v per cell otherwise cell may not recover. Never seen a 5v nicad.....nominal voltage per cell is 1.2v.......fully charged it can reach 1.45v per cell.... Memory effect usually shows as reduced capacity BUT so does a faulty cell...... To recycle automatically look for nicad cycler

 

[Rolf]

Do not discharge below 0.8v per cell otherwise cell may not recover. Never seen a 5v nicad.....nominal voltage per cell is 1.2v.......fully charged it can reach 1.45v per cell.... Memory effect usually shows as reduced capacity BUT so does a faulty cell...... To recycle automatically look for nicad cycler

Thankyou Bluejets have 4 1.2 tied in series I will recharge at 3.2 voltsTTY

 

[nlol]

Ah - no - you'll have to apply a voltage at least as high - and not much more - than their fully charged voltage. Itis better to do this individually. In series each will have a different resistence and voltage drop giving somewhat unmanageable results/charging for each battery. For the same reason, charging them in parallel is not a good idea. Someone else will have to advise you about charge rates but you should not simply charge them with a regulated power supply set at the maximum charge voltage. Doings so would almost certainly damage a deeply discharged battery.

 

[Alec_t]

Have a read of this.

 

[Bluejets]

Ah - no - you'll have to apply a voltage at least as high - and not much more - than their fully charged voltage. Itis better to do this individually. In series each will have a different resistence and voltage drop giving somewhat unmanageable results/charging for each battery. For the same reason, charging them in parallel is not a good idea. Someone else will have to advise you about charge rates but you should not simply charge them with a regulated power supply set at the maximum charge voltage. Doings so would almost certainly damage a deeply discharged battery.

The op was quoting his cutoff voltage NOT his charging voltage