Some POWERful questions ...
rucinski
I have four Nikko 7.2 1600 Nicad battery packs. New to this game and not
very knowledgable in the field of electronics, I wonder if anyone would be
willing to ansewer a few (very basic) questions for me ...
1. Is it worth my purchassing 7.2 Ni-Mh batteries next time as opposed to
Nicads - eg
http://www.modelsportuk.com/static/ms_static_20010307/empty.html?Item=10084
What are the advantages / disadvantages - would they work with my Nicad fast
charger?
2. My local stockist has some 7.2 nicads that are 1900 as opposed to 1600 -
what exactly does this higher rating mean for a fully charged battery when
I'm using it.
3. Is there anything higher than 1900 - and if so, where - and will it work
with my current Nikko fast charger?
4. My fast charger really doesn't seem to do as good a job at charging as
the 3-hour charger that came with my car - any reason? How "dangerous"
would it be to put the batteries through the fast charger twice?
5. Where's a good newby site for learning what I need to know re the
electrical side of R/C?
If you've got this far, thanks for taking the time to read - I'd very much
appreciate your comments.
Tony
Jonny Hodgson
> I have four Nikko 7.2 1600 Nicad battery packs. New to this game
and not
> very knowledgable in the field of electronics, I wonder if anyone
would be
> willing to ansewer a few (very basic) questions for me ...
I'll do what I can!
> 1. Is it worth my purchassing 7.2 Ni-Mh batteries next time as
opposed to
> Nicads - eg
>
http://www.modelsportuk.com/static/ms_static_20010307/empty.html?Item=
10084
> What are the advantages / disadvantages - would they work with my
Nicad fast
> charger?
Well, I tried to look at the link but my connection was being sh*te...
If that's a pack of proper, Sanyo 3000 mAh Ni-MHs then a) the
advantage is quite a bit more runtime than Ni-CDs, and b) only if you
have a good-quality peak charger which has been designed for the job.
I suspect I'm going to answer that new question in a minute... ;-)
> 2. My local stockist has some 7.2 nicads that are 1900 as opposed to
1600 -
> what exactly does this higher rating mean for a fully charged
battery when
> I'm using it.
More runtime. A 1.9 Ah (1900 mAh) pack of cells (in theory at least)
will allow you to draw one amp for 1.9 hours, or 1.9A for one hour, or
any similar combination. It doesn't quite work like that because
things get inefficient at high current draw, but that's the basics.
> 3. Is there anything higher than 1900 - and if so, where - and will
it work
> with my current Nikko fast charger?
I suspect that these might not be standard 'sub-C' size cells, since
neither 1600 nor 1900 are standard capacities. The ones I do
recognise are: 1400 SCR, 1700 SCRC, 2000 RC and 2400 if we're talking
nicads.
> 4. My fast charger really doesn't seem to do as good a job at
charging as
> the 3-hour charger that came with my car - any reason? How
"dangerous"
> would it be to put the batteries through the fast charger twice?
It sounds like you've got a 'timed' charger - which runs at a constant
current, for a set length of time. These are crap. Save yourself
lots of hassle and buy a 'peak' charger, which charges at a constant
current until the cell voltage stops increasing and starts to drop
again, which is a sure sign that a nicad is charged.
If you really don't want to spend the money, the other sure sign is
that the cells become warm to the touch - not hot, but definitely more
than just tepid - so you can keep fast charging them until they're
nicely 'cooked'. However, if you do this you *must* be careful not to
let them get hot otherwise they could, ultimately, explode (although I
think you have to overcharge them by quite a bit to make it happen).
> 5. Where's a good newby site for learning what I need to know re
the
> electrical side of R/C?
Probably Tom's, but I can't remember the URL offhand and I expect
he'll post it soon ;-)
HTH,
Jonny
cruuk
guy myself but i can provide you with some info.
ni-mh/nicad
the single biggest differrence between these battery types is the fact
that ni-mh batteries are not affected much by charge/discharge cycles.
the amount of charge they hold will not considerably dissapear as
time wears on and you charge discharge repeatedly. these types can
accept charges easily without being fully discharged first as you have
to do with a nicad battery. another difference between them is nicads
tend to have a higher voltage. what this gets you is more power or
"punch" out of your motor. as far as your charger, if it is just a
timer type it should work fine but if it is a peak charger then dont
use it for ni-mh batts unless it is designed for it. more about
chargers later. if you already have 3 of them you can keep using
them.. they will work fine or you can sell them with your truck if
thats what you are going to do and get some higher capacity cells
which leads to your next question.
1900 vs 1600 etc
this represents the total charge capacity of the battery. they both
supply the same voltage but the 1900's will last longer between
charges... something very desireable in r/c. capacities for nicads go
up to 2400 mah i believe? guys? and for ni-mhs go up to 3000 mah.
these batteries will of course cost considerably more than your 1600
or 1900 sport packs.
charger
im assuming your nikko quick charger is probably a timer type.. 15
minutes or some such thing. those types are acceptable for charging
batteries but it will in most cases not supply the battery with a full
charge... especially if you get a higher capacity battery. what you
can do to charge it is keep it on until you feel the battery become
warm to the touch and unplug it. or an even better way is to get a
peak charger which will automatically determine when the battery has
accepted all the charge it can and will shut off or switch to trickle
charge. with a lot of these chargers you can set the amount of power
"amperage" that you charge with and that will determine how long it
will charge for. duratrax and novak are a couple of companies that
make them.
dont know much for electronic websites but im sure there are plenty of
guys here who can suggest some
hope this helped
"rucinski" <ruci...@ntlworld.com> wrote in message news:<ZlbQ6.4498$lm5.8...@news6-win.server.ntlworld.com>...
Tom
(*SNIP!*)
> > 5. Where's a good newby site for learning what I need to know re
> the
> > electrical side of R/C?
>
> Probably Tom's, but I can't remember the URL offhand and I expect
> he'll post it soon ;-)
>
http://www.csc.uvic.ca/~tyounger/hafh/rc
___
TTTTT OO M M The sixth sick shiek's sixth sheep's sick. |~~~|
T O O MM MM @o o@
T O O M M M So if it is in it or if it is on it, it is *
T OO M M as it is, be it in it or on it. `-'
Tom
> good to see you are getting into r/c :). anyways im more of a nitro
> guy myself but i can provide you with some info.
>
> ni-mh/nicad
>
> the single biggest differrence between these battery types is the fact
> that ni-mh batteries are not affected much by charge/discharge cycles.
> the amount of charge they hold will not considerably dissapear as
> time wears on and you charge discharge repeatedly.
Actually, NiMH has a significantly shorter cycle life than NiCad.
these types can
> accept charges easily without being fully discharged first as you have
> to do with a nicad battery.
People do much more damage to their NiCads by ensuring that they are fully
discharged after a run than they prevent by doing so. The truth is that
NiCads work just fine without being fully dischared every cycle. NiMH are
succeptable to voltage depression (often referred to as "memory", even
though that term normally referrs to something else which doesn't exist)
just like NiCad; the effect is due to the nickle plate in the cell, which
is common to both types.
In short, don't worry about it, and you'll be far better off than those
who do.
rucinski
If only I'd come along a few weeks ago ...
Tony
Jonny Hodgson <jp_ho...@engineer.com> wrote in message
news:etsre9...@turing.8bondclose.lboro...
cruuk
thx for the correction.