NiCad o NiMh alin mas maganda?

[cspcboy]

Ano po kaya ang advantages at disadvantages ng NiCad at NiMh na baterya?

[creedcradle]

"NiCad (Nickel Cadmium) batteries are good for small to medium size range robots. They have the highest current output, are more affordable than NiMH's, and can be recharged within one or two hours. However recharging NiCad batteries is a black art. Ever notice how some older cell phone batteries just do not last as long on a single charge as when you first bought it? This is called memory effect. A NiCad, over many charges, can only store less and less energy after each recharge. To prevent memory effect, whenever you wish to recharge your NiCad, you must first fully discharge it. Just hook up both battery leads to a cute kitten until it stops moving. I guess a motor would work too . . . And remember, NiCad batteries contain toxic cadmium stuff, so save a squirrel and recycle/dispose of it properly. " from John of Washington US NAVY.

"NiMH (Nickel Metal Hydride) batteries are really neat. Older cell phone batteries were often NiMH. You can recharge them as much as you want, they have good current output, and have the highest energy capacity. I would recommend them for small size robots and for powering circuits. Note, NiMH batteries usually take like 10 hours to recharge depending on various factors. Also, some NiMH batteries have a high self-discharge rate. In other words, leave it for a week or so, and you will find an entirely discharged battery. But fortunately NiMH battaries can last many more cycles than your typical NiCad battery. " -from John of Washington US NAVY.


-creedcradle

[creedcradle]

http://en.wikipedia.org/wiki/NiCd
http://en.wikipedia.org/wiki/Nickel_metal_hydride_battery

-creedcradle

[express]

This would depend on your requirements.
  If you want speed charging - use NiCad
  current supply - use NiCad
  memory effect - use Ni-Mh
  self-discharge - NiCad is better

 

[Ganda692002]

This Simple Table maybe in Order...........

How to charge - when to charge table
http://www.batteryuniversity.com/partone-14A.htm

[homer530]

Ang problema sa NICAD ay yong memory effect.  Kapag di pa full discharge ay i-charge mo agad ay di nakakapag-charge ng full capacity. Para sa akin ay mas maganda NIMH kasi walang memory effect kapag i-charge mo.

[mvocray]

i was researching the topic a while ago. if you look at: http://en.wikipedia.org/wiki/Memory_effect, or even battery specialist specifications such as http://www.gpbatteries.com/html/pdf/NiCd.pdf, low capacity NiCd batteries typically do not suffer from memory effect as much as we think. apparently, overcharging are the main culprits to the decrease in capacity. This is common in all types of battery (although NiCd may be less robust to such issues, maybe someone with better experience can tell).

i think capacity(NiMH), discharge requirements (NiCd > NiMH), and affordability (NiCd > NiMH) would be the primary concerns provided you have a proper charger.

[bravokilo]

I have used Nicads for so many years in my model planes(RC),to power the RX and the servos,and TX.  We called nicads "the old reliable". And somehow memory was never an issue maybe it was because 4-5 flights would discharge it anyway. Also, we had what Futaba(mostly) provided us with, a 10C wall charger with no frills. It was a transformer+diode thing.  10C meant the charging rate was 10% of capacity. In fact I found out many chargers were charging it at a lower rate. and typically, our set came with a 500 mah AA batteries. So, the charging rate was 45 ma to 50 ma. It always worked if plugged it in the night before. And they lasted years since nicads usually have 1000 charges in them. Then came the fancy chargers which sensed the delta peak of nicads and end the charging. They even discharged the cells first.In RCPhilippines , I wrote a lengthy article on the fallacy of using excessive capacity for nicads. You will end up using the top end of the charger anyway since your use is a fraction of the capacity  and to you follow the rule to discharge, you will end up wasting on charging the cells only to discharge it.

     Came the Nickel Metal Hydrides, the brother of nicads. They are both nickel based. For the same weight, MH can have higher capacity than nicads. Or put it the other way around, for the same capacity, MHs weights less. Good for us modellers when our aircraft do not like weight. There is no need to discharge the MHs, however, there is one problem encountered. MHS have lower "current delivery rate" than brother Nicad. In Lipos today, it is called the C, which is how much current can the battery deliver.|So, later on many of us went back to the nicads for larger models using more electronics for the simple reason,nicads do not starve the system. Today, lipos replaced the nicads forthis need. Lipos surpass the nicads in current delivery rate. 1000MAH Lipo may be capable of 30C, meaning 30x1000ma or 30AMPS!

     One big drawback of the Nicad is corrosion. the negatie line covered in black vynil corrodes the copper and find its way into the boards. and this is one reason why some cameras is marked  "do not use rechargeables". It has nonting to do with voltage but a a lot with corrosion. 

     Today we use MHs on low current requirements such as the TX and lipos on the receiver and servos which can deliver the punch. We even put Li-ion or Li-polys (lipos) on the TX. Problem withli batts is their being more delicate than the nickel based batteries.

BK

[iyo karpo]

di ba banned na ung NiCad? may nagbebenta pa niyan?

[bravokilo]

Nicads can still be bought in many places. Some China toys use nicads. for your battry need, go to the end of Raon doon malapit na sa Ongpin Stree sa Sta.Curz. andun you ELFOH. Puro batteries...

BK

[iyo karpo]

ung Cadmium pollution sa environment - cause ng birth defects.

[bravokilo]

Yes, amen. ang cadmium destroys our kidneys when exposed to it. Dapat talaga alisin na sa mercado. Kaya siguru inintroduce and metal hydrides.

BK
 

[dummy_c]

NIMH gamit ko...