> I was installing freshly charged nicads in my Tx yesterday and had a bit of
> a contact problem. While resolving such, my multimeter showed that the
> total voltage of the 8 batteries was 10 instead of 12 (as would be the case
> with lead-acid). I removed one nicad and saw that it was rated for only
> 1.25 volts. So, the voltage delta in my Tx is 2.0v and 1.0v in the Rx.
> Because the voltimeter on the Tx is calibrated for 12v, it shows only 83%
> of full power and gives me the feeling that I'm low on "juice." I at first
> thought I had bought the wrong ones, but after looking through Tower's Big
> Book I get the impression that *all* AA sized nicads are only 1.2 - 1.25
> 1. Is it true that all AA nicads are 1.2 - 1.25 volts?
They say it's 1.25V. Theoretically, it's 1.2 volts. And depending
on the load, it could be a 1.1V average during the discharge cycle.
> 2. Will/does this have any effect on the radio system's performance?
Lower range definitely. But you should be fine. Nominally, 8 cells
yeild a 9.6V pack, which is close enough to 12V. Personally, I just
use AA Alkalines since you don't replace trasmitter/receiver batteries
that often anyway.
> 3. Is the discharge rate (discharge/time = amperage?) more important than
> the voltage?
Depends on the application. For a radio system, where the current draw
is pretty small, I think maintaining a proper voltage is more important
because it gives you longer range. Even if you hooked a pack of 10
Trinity VIS-MATCH RS2000 cells to your transmitter, it is still going
to give you the same range as 8 AA Alkaline batteries.
> 4. What is, how much is, where is the best AA nicad I can buy?
Them yellow Sanyo 600ma ones are probably the best you can get your
hands on. But since no Ni-Cad can produce more than 1.2V per cell,
switching brands/models won't help you as long as you are using
> 5. I want *standard* batteries with big ***s and flat butts: tabbed or
Non-tabbed. Tabbed ones are for when you want to put together a
> (I realize the temptation, but no jokes on #5, please!)
In the end, I recommend plain old Alkaline for transmitter/receiver
batteries. It gives you the voltage you want and I last really
long since the current draw is so small. I've been using a set
since the beginning of the year.
> Thanks in advance for the help!
> Howard L. King
Lee Cao - http://www.FoundCollection.com/~ligeng
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