Ni-Cads v. Duralites - A Comparison

By Red Scholefield:  http://www.rcbatteryclinic.com/

 

Technical Comparison using:       6 volt (5x 1.2 V) AA 800 mAh Ni-Cads v.

                                                6 volt (2x 3,2V) AA 800 mAh LiLxMnO2

 

Weight

NI-Cad 4.25 oz

Duralite 1.2 oz

 

Internal resistance

Ni-Cad 44 mohms

Duralite 160 mohms

 

Cycle Life (100% DOD)

Ni-Cad 500+ to 80% of rated capacity

Duralite 300-350 to 65% of rated capacity

 

Cycle Life (50% DOD)

Ni-Cad 1000+ to 80% of rated capacity

Duralite 600 to 65% of rated capacity

 

Capacity self discharge

Ni-Cad 1-2%/day

Duralite .04%/day

 

Discharge pack to zero volts

Ni-Cad cells reversed - recoverable

Duralite will destroy cell

 

Charging

Ni-Cad constant current

Duralite constant voltage

 

Fast Charge

Ni-Cad up to 4C

Duralite C/3.2 max*

          *Fast charge should be applied for not more than 10% of cycling life

 

Over charge at C/10

Ni-Cad very slight reduction in life

Duralite will destroy cell

 

Max discharge current (pulsed)

Ni-Cad 18 A

Duralite 2A

 

Max discharge current continuous

Ni-Cad 9A

Duralite 250 ma (per mfg. spec.)

 

Discharge temperature range

Ni-Cad -20C to +60C

Duralite -30C to +55C

 

Storage Temp

Ni-Cad -30C to +50C

Duralite 0C to +30C

 

Economics:

Ni-Cad 6 volt 700 mAh @ $13.95

Lithium Metal (Duralite) 6 volt 800 mAh @ $34.95

 

Cycle life of Ni-Cad to 90% of capacity - 500 cycles = 315 Ah

Cycle life of Lithium Metal to 90% of capacity - 300 cycles = 216 Ah

 

 [Assumes that both system give rated capacity for duration of their life

 -when in fact Ni-Cad yields 80% of capacity while Lithium Metal yields 50%

 at end of life as defined by manufacturer of each system]

 

 Cost of Ni-Cd  $19.93/Ah

 Cost of Lithium Metal $43.69/Ah

 

 Over life of battery:      Cost of Ni-Cad = $0.044/AH

                                      Cost of Lithium Metal = $0.16/Ah

 

Charger for Ni-Cad TX and RX - (provided with radio system) - add $5.00

for sustaining trickle charger.

 

Charger for Lithium Metal TX and RX $28.95 each = $57.90

 

Cycler to check battery performance:

Ni-Cad - $125

Lithium Metal - none available

 

Fast charge (peak detection and cycler)

Ni-Cad - $125

Lithium Metal - cannot be fast charged.

 

Investment in Ni-Cad battery charging can be transferred to another

technology (Ni-MH) should the Ni-Cad technology no longer be available.

Investment in Lithium Metal battery charging has no known use should

Lithium Metal no longer be available. (Present manufacturer, Tadiran, has

announced that they will no longer produce the product- except on

"special" runs for the hobby market - sale of the technology has been

rumored but not substantiated, long term availability of Lithium Metal

technology somewhat in question).

 

                                      IT’S YOUR CHOICE!