Why NiCad and not NiMh?

Why NiCad and not NiMh?

Post by Dan Cha » Sun, 11 Apr 1999 04:00:00



I'm just wondering why NiCads are so popular and no one uses NiMhs. Is
it because NiCads have better drain capabilities? NiMh seems to have
higher capacity...plus, they don't have memory. What about LithiumIon?
My laptop battery is pretty small and it has 5700mAh at 11.1 volts. But
I guess since it costs like $200 oh well. Just some random thoughts of
the day.....
 
 
 

Why NiCad and not NiMh?

Post by Antonio Garz » Sun, 11 Apr 1999 04:00:00


I've heard of NiMh being used in lower drain apps such as a radio.
They're more $$$$.

Lithium Ion is supposed to be the future, having high drain capabilities
and the best storage capacity.

I know someone is going to post disagreeing with my and with your
statement about memory (memory?  what memory???).

Antonio

Quote:

> I'm just wondering why NiCads are so popular and no one uses NiMhs. Is
> it because NiCads have better drain capabilities? NiMh seems to have
> higher capacity...plus, they don't have memory. What about LithiumIon?
> My laptop battery is pretty small and it has 5700mAh at 11.1 volts. But
> I guess since it costs like $200 oh well. Just some random thoughts of
> the day.....


 
 
 

Why NiCad and not NiMh?

Post by Jon » Sun, 11 Apr 1999 04:00:00


Quote:

> I know someone is going to post disagreeing with my and with your
> statement about memory (memory?  what memory???).

Agree, NiCads will develop a memory if not completely discharged before
recharging.  In RC cars this seldom happens because of the application, and
especially with the trick chargers available.

Why not NiMh?  Probably cost.

 
 
 

Why NiCad and not NiMh?

Post by Dan Cha » Sun, 11 Apr 1999 04:00:00


I do know that with Lithium Ions you have to charge each cell separatly.
That's why there are so many tabs on a Lithium ion battery. I've heard it's
because you have to be very careful with the charging characteristics of each
battery. That would be kinda annoying for R/C. You'd have to dissasemble the
pack to recharge it....or I guess you could have a new kind of connector.

So NiMh has memory? I use the sony pak in my discman and it lasts over 11
hours. That's twice as long as with NiCads. The AAs have 1200mAh. But
then...I can get over 18 hours with regular alkalines.

Quote:

> I've heard of NiMh being used in lower drain apps such as a radio.
> They're more $$$$.

> Lithium Ion is supposed to be the future, having high drain capabilities
> and the best storage capacity.

> I know someone is going to post disagreeing with my and with your
> statement about memory (memory?  what memory???).

> Antonio


> > I'm just wondering why NiCads are so popular and no one uses NiMhs. Is
> > it because NiCads have better drain capabilities? NiMh seems to have
> > higher capacity...plus, they don't have memory. What about LithiumIon?
> > My laptop battery is pretty small and it has 5700mAh at 11.1 volts. But
> > I guess since it costs like $200 oh well. Just some random thoughts of
> > the day.....

 
 
 

Why NiCad and not NiMh?

Post by Dan Cha » Sun, 11 Apr 1999 04:00:00


cost??? People pay tons of money for matched cells and gold stuff. I'm sure
there would be people paying top dollar for the best batteries there are.

About this memory in NiCads....do I have to discharge it below the level I
would normally run it at? like, is it not ok to just charge it after I think
it's too weak? maybe I'm confusing you....I guess my real question is, is this
memory going to be set at the point where you first charged it without
discharging it. Like if I run my car for 4 mins and decide that it's too slow,
but the car can still go for 2 more mins. Do I have to discharge the rest of
the power for the pack to be in good condition, or can I just recharge it after
4 mins and get 4 good mins out of the pack.....maybe I'm still confusing
you..oh well. I guess I'll just use a discharger anyway, how's that.... =)

Quote:


> > I know someone is going to post disagreeing with my and with your
> > statement about memory (memory?  what memory???).

> Agree, NiCads will develop a memory if not completely discharged before
> recharging.  In RC cars this seldom happens because of the application, and
> especially with the trick chargers available.

> Why not NiMh?  Probably cost.

 
 
 

Why NiCad and not NiMh?

Post by Erro » Sun, 11 Apr 1999 04:00:00


i think its internal resistance. NIcds have lower internal resistance
than nimh.  therefore they can discharge faster.
Quote:


> > I know someone is going to post disagreeing with my and with your
> > statement about memory (memory?  what memory???).

> Agree, NiCads will develop a memory if not completely discharged before
> recharging.  In RC cars this seldom happens because of the application, and
> especially with the trick chargers available.

> Why not NiMh?  Probably cost.

 
 
 

Why NiCad and not NiMh?

Post by jjord.. » Sun, 11 Apr 1999 04:00:00


As for NiMH in R/C, I heard from heli pilots that NiMH isn't good w/
vibration, that's why thay still
 use NiCd's.  There have been claims of heli vibration causing the NiMH
batts to not work properly
and causing the electrics to not run.
I believe this can be analogous to R/C cars in jumps and the like.  It would
suck to lead
 a race and hit a tabletop and have your car totally stop.
Just something I've heard along the way.
J-

**** Posted from RemarQ - http://www.remarq.com - Discussions Start Here (tm) ****

 
 
 

Why NiCad and not NiMh?

Post by PaulO575 » Mon, 12 Apr 1999 04:00:00


Some battery info sites that you might find informative:

http://www.954access.net/~matt/index.html

http://www.repairfaq.org/ELE/F_NiCd_Battery.html

 
 
 

Why NiCad and not NiMh?

Post by Jon » Mon, 12 Apr 1999 04:00:00


Quote:

> .......maybe I'm confusing you........maybe I'm still confusing
> you..oh well.

It appears that you might be the one who is confused. ;-)  
 
 
 

Why NiCad and not NiMh?

Post by Dan Cha » Mon, 12 Apr 1999 04:00:00


yeah =) oh well, that's why I'm switching over to gas....too much
trouble with electrics......peak chargers, dischargers, mod motors,
stock motors, motor timing, speed controls, matched cells...the cost of
matched cells, com lathes... Nitro seems more fun. It won't slow down as
the battery dies, it can run and run and run, engines can be rebuilt. I
dunno, what do you think....
Quote:


> > .......maybe I'm confusing you........maybe I'm still confusing
> > you..oh well.

> It appears that you might be the one who is confused. ;-)

 
 
 

Why NiCad and not NiMh?

Post by copu.. » Mon, 12 Apr 1999 04:00:00


Quote:

> I'm just wondering why NiCads are so popular and no one uses NiMhs. Is
> it because NiCads have better drain capabilities? NiMh seems to have
> higher capacity...plus, they don't have memory. What about LithiumIon?
> My laptop battery is pretty small and it has 5700mAh at 11.1 volts. But
> I guess since it costs like $200 oh well. Just some random thoughts of
> the day.....

Check out the reason why NiCd's are the best choice (for now):

http://www.cadex.com/cfm/index.cfm?Pg=151&Lp=55&Db=&Mo=

 
 
 

Why NiCad and not NiMh?

Post by lt1_z28DELET.. » Mon, 12 Apr 1999 04:00:00



Quote:

>Check out the reason why NiCd's are the best choice (for now):

>http://www.cadex.com/cfm/index.cfm?Pg=151&Lp=55&Db=&Mo=

Sounds to me like NiMH is the thing to use for transmitter and
reciever packs. I'm going to have to build one for my 7UAFS. Ever try
to swap a Tx pack in the middle of a 2 hour thermal flight? Well, me
either, but in my 3 billionth 2 minute flight of the day I had to ;)

Steve

 
 
 

Why NiCad and not NiMh?

Post by IJdo Dijkst » Mon, 12 Apr 1999 04:00:00


Quote:

>yeah =) oh well, that's why I'm switching over to gas....too much
>trouble with electrics......peak chargers, dischargers, mod motors,
>stock motors, motor timing, speed controls, matched cells...the cost of
>matched cells, com lathes... Nitro seems more fun. It won't slow down as
>the battery dies, it can run and run and run, engines can be rebuilt. I
>dunno, what do you think....

Well, having seen nitro cars in full racing glory (i've seen them
before, but never at a track), I'll stick to electric. Under racing
conditions, they don't seem to last longer on a tank of fuel compared
to electric (although refueling is much easier), and there's starting
problems...

----
Corally C4: who needs Viagra?

 
 
 

Why NiCad and not NiMh?

Post by Tom » Mon, 12 Apr 1999 04:00:00


Quote:

> I'm just wondering why NiCads are so popular and no one uses NiMhs. Is
> it because NiCads have better drain capabilities? NiMh seems to have
> higher capacity...plus, they don't have memory. What about LithiumIon?
> My laptop battery is pretty small and it has 5700mAh at 11.1 volts. But
> I guess since it costs like $200 oh well. Just some random thoughts of
> the day.....

NiCads don't have memory either.

NiCads can withstand very high charge and discharge currents well, and are
one of the very few battery types that do not get damaged when drained
completely.  These characteristics, among many others, make them still the
ideal battery available for R/C cars, unlike the others you have
mentioned.  What are their ratings under a 50 ampere load?!?

___
TTTTT   OO   M   M The sixth sick shiek's sixth sheep's sick.   |~~~|

  T    O  O  M M M So if it is in or if it is on it is as it is,  *  
  T     OO   M   M        be it in or on.                        `-'

 
 
 

Why NiCad and not NiMh?

Post by Tom » Mon, 12 Apr 1999 04:00:00


Quote:


> > I know someone is going to post disagreeing with my and with your
> > statement about memory (memory?  what memory???).

> Agree, NiCads will develop a memory if not completely discharged before
> recharging.  In RC cars this seldom happens because of the application, and
> especially with the trick chargers available.

> Why not NiMh?  Probably cost.

Sorry to sound like a***head, but why don't you try to figure out a fact
or so before posting a reply?

NiCads do not suffer from memory.  It's not an opinion where you agree or
disagree.

NiMH cells do not withstand the current demands necessary for R/C car
applications in their current incarnations.  Nor can they withstand
deep-cycles like NiCads can.

___
TTTTT   OO   M   M The sixth sick shiek's sixth sheep's sick.   |~~~|

  T    O  O  M M M So if it is in or if it is on it is as it is,  *  
  T     OO   M   M        be it in or on.                        `-'