Ni-mh versus Ni-cd

[FREYAsinaz]

Both are good if used in the right way. Read-up and u'll know why.

http://www.ussc.com/~turner/nicds.html

From my own experience, for Rx batt, I realised Nicds (e.g. 2400mAh) have better staminer in terms of constant voltage...incidently its very important to R/C equipment. Especially for Helis where high torque servos and gyro are used.

NiMh (e.g. 800mAh or 2100mAh) works well in planes where standard servos are used and the load in this case is nothing compared to a heli.

In Tx, I have used both and found them to be ok, but have stuck to NiCds (1000mAh) as the voltage is still a factor for maintaining constant signal.

NiMh are good in Digital Camera application. All my 20pcs of 2100mAh AA Sanyo NiMh previously used in my R/C equip are now serving my DC.

bro,

ur attachment is very useful...it also did elaborate on the do's and don't on batteries, treating ur battery carefully, explaining the diff..., etc

very useful...eh infact do you fly yesterday after ur coffee break at blk 198 while waiting for the rain to stop?

[9VDXN]

Well, just can't help it but to barge into this thread...

I tend to think otherwise about the NiCD and NiMH arguement.
I've been playing with NiCD & NiMH sub-c batts since battery technology was no more than 1000mah per cell, and the only disadvantage of NiCD cells are the memory effect.

As for voltage drops, both NiCD and NiMH cells have a rather steep voltage drop curve. (Ie. as long as voltage drops below a certain voltage per cell, battery performance will drop DRASTICALLY...)

It is true that NiCD cells have a slightly lower operating voltage point....i think should be about 0.8v/cell for NiCD whereas for NiMH is about 0.9v/cell as lowest operating voltage.

Myths about NiCD being able to last longer or sustain a decent voltage output is also not really true as long as you are comparing batteries of the same specifications. (ie. SUb-C to sub-c & mAh rating to mAh ratings)

Amp ratings are always relative to the voltage drop...if a battery is specified as 3000mah, it means at the correct operating voltage, it WILL BE ABLE to give 3000mah before the cells reaches the 0.9v per cell and results in loss of performance.

In RX battery operations, it is true that voltage drop will affect performance especially when using Digital servos. Speed and torque will be lost when voltage drops....but they should still be able to last u till u reach 0.9v per cell....so either you use NiCD or NiMH, when cell drops to the sustainable voltage, performance suffers.

Another point to note about RX batt applications is the type of cells...stock AA sized cells of about 1000mah might not be able to sustain the amp draw of digital servos if their C ratings is only like about 1C....My digital servos is drawing about 1.5-2 amps at 4.8v, and I learn that the hard way after suffering 2 flight failures. Wires & connectors can also play a big part in delivering/restricting currents flow...say if your cables can only sustain 1amp draw and your servos is drawing 1.5amps...then your cable is restricting the full capability...then heat will be generated, and energy will be loss, etc.....


In simple words, believe it or not, from my own experiments & experience, I still think NiMH cells are better over NiCD coz they're pretty maintainence free....

[FREYAsinaz]

Well, just can't help it but to barge into this thread...

I tend to think otherwise about the NiCD and NiMH arguement.
I've been playing with NiCD & NiMH sub-c batts since battery technology was no more than 1000mah per cell, and the only disadvantage of NiCD cells are the memory effect.

As for voltage drops, both NiCD and NiMH cells have a rather steep voltage drop curve. (Ie. as long as voltage drops below a certain voltage per cell, battery performance will drop DRASTICALLY...)

It is true that NiCD cells have a slightly lower operating voltage point....i think should be about 0.8v/cell for NiCD whereas for NiMH is about 0.9v/cell as lowest operating voltage.

Myths about NiCD being able to last longer or sustain a decent voltage output is also not really true as long as you are comparing batteries of the same specifications. (ie. SUb-C to sub-c & mAh rating to mAh ratings)

Amp ratings are always relative to the voltage drop...if a battery is specified as 3000mah, it means at the correct operating voltage, it WILL BE ABLE to give 3000mah before the cells reaches the 0.9v per cell and results in loss of performance.

In RX battery operations, it is true that voltage drop will affect performance especially when using Digital servos. Speed and torque will be lost when voltage drops....but they should still be able to last u till u reach 0.9v per cell....so either you use NiCD or NiMH, when cell drops to the sustainable voltage, performance suffers.

Another point to note about RX batt applications is the type of cells...stock AA sized cells of about 1000mah might not be able to sustain the amp draw of digital servos if their C ratings is only like about 1C....My digital servos is drawing about 1.5-2 amps at 4.8v, and I learn that the hard way after suffering 2 flight failures. Wires & connectors can also play a big part in delivering/restricting currents flow...say if your cables can only sustain 1amp draw and your servos is drawing 1.5amps...then your cable is restricting the full capability...then heat will be generated, and energy will be loss, etc.....


In simple words, believe it or not, from my own experiments & experience, I still think NiMH cells are better over NiCD coz they're pretty maintainence free....

bro,

after readin ur thread...it need to take quite some time to digest (my eyes goes from to this to this to )

good knowledge i got from u guys....thanks

[9VDXN]

hehehe, in another simple words, as loong as you match your applications properly, charge and maintain your batteries properly, the batts will not ever fail on u....

[mechplas]

bro,

ur attachment is very useful...it also did elaborate on the do's and don't on batteries, treating ur battery carefully, explaining the diff..., etc

very useful...eh infact do you fly yesterday after ur coffee break at blk 198 while waiting for the rain to stop?

How come u know?....IDENTIFY YOURSELF..who's that!

Yah lah, went to fly after the rain, Managed two flights. :na

[YZY]

Em the sanyo 1100 mah batts sometimes u see as receiver packs... never seen packed as transmitter packs though dunno y

[X34]

1100 are used in Futaba WC and Jr 10x. JR has it as an option for other models.

[FREYAsinaz]

How come u know?....IDENTIFY YOURSELF..who's that!

Yah lah, went to fly after the rain, Managed two flights. :na

the one with ah beng's tune pipe....

cheers....

[mechplas]

the one with ah beng's tune pipe....

cheers....

Oh IC, that small plane making a lot of noise....ok I know liao.