What is the maximum Ni/Ca battery charge current?

[grittinjames]

Ni/Ca battery charger

Hi,

I having 700mah Ni/Ca Battery. Please suggest what is the maximum charge current,
At what voltage I can assume battery is charged fully?

Thanks

 

[Audioguru]

Ni/Ca battery charger

Ni-Cad battery cells are obsolete and have been replaced by Ni-MH cells that have 3.5 times more capacity.

They reach a voltage of about 1.5V per cell when fully charged. The voltage and temperature rises when they are overcharged. The datasheet for the battery lists its max recommended charging current.

Look at the spec's on the datasheet from a manufacturer like Energizer. Energizer has a Ni-Cad Applications Manual and a Ni-MH Applications Manual on their website.

 

[fsmyth]

Ni/Ca battery charger

**broken link removed**

 

[viperpaki007]

Ni/Ca battery charger

normally battery charging current depends upon the mode of charging e.g fast(50% of C to 100% of C), slow(10% of C to 20% of C ),trickle (3.3% of C to 5% of C)...but for a normal case if your charger puts out current a, then you can charge batteries with a capacity between a and a * 3.5 amp-hours


indication for completion of charge is a slight dip in o/p voltage of battery or a rise of temperature

 

[VVV]

Re: Ni/Ca battery charger

For fast-charge you can go with C, that is 700mA. Charge termination should be based on -ΔV, which for NiCd is about 16mV. So when the voltage drops by 16mV, stop the charging. Also, there is a time limit on the charge, which should be set to 1h, and a temperature termination, i.e. charging should end if the battery temperature exceeds 45C.

 

[Audioguru]

Ni/Ca battery charger

A fast charger should have a voltage detection circuit that will sense a charged battery and refuse to overcharge it.