How may cycles to prep new NiCad's ?

[Tor Rasmussen]

Just got som new NiCad's for my Tx and Rx.
Thought I'd cycle them a couple of times to prepare them for the long runs.

How many cycles do you recommend ?

[Tim van Halteren]

> How many cycles do you recommend ?

I cycle them until I don't see a significant difference in the charge that
they return. It will probably depend on the cell type but I cycle 3-5 times
before I use a new NiCd battery.

Tim

[Beav]

"Tor Rasmussen" <tor.rasmussen@tiscali.no> wrote in message
news:yI0ia.919$y3.48447@news010.worldonline.dk...
> Just got som new NiCad's for my Tx and Rx.
> Thought I'd cycle them a couple of times to prepare them for the long
runs.
>
> How many cycles do you recommend ?

Being a lazy old fashioned (and old) twat, I don't.

I buy, fit, charge, fly and after a couple of years, I throw 'em away.

Seems to work pretty well as I've never expereinced a battery problem in
over 35 years in the hobby.

'Course I know bollocks all :-)


--
Beav


Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk

[Neil Patmore]

Your better off conditioning the batteries using a C/10 charge (1/10th the
capacity) for 16 hrs for the first charge.
Chargers like the Supernova peak detect 'a' cell. So if one cell is fully
charged, the charger stops charging before the other cells reach their full
capacity.
The same goes for discharging.

Conditioning the pack ensures all cells are at the same level when the
charge begins.

"Tor Rasmussen" <tor.rasmussen@tiscali.no> wrote in message
news:yI0ia.919$y3.48447@news010.worldonline.dk...
> Just got som new NiCad's for my Tx and Rx.
> Thought I'd cycle them a couple of times to prepare them for the long
runs.
>
> How many cycles do you recommend ?
>
>

[Rhodesst]

>Chargers like the Supernova peak detect 'a' cell. So if one cell is fully
>charged, the charger stops charging before the other cells reach their full
>capacity.

I don't understand how they can do that. The cells in the battery pack are
connected in series so the voltages are added together. How can the charger
detect the voltage level of any "one" cell under these circumstances?

All I know is this. When I started using the SuperNova, I also started getting
better flight times out of my battery packs. The difference wasn't what I'd
call dramatic, but it was enough to be noticable.

Fly Safe,
Steve R.

[Rich Werth]

> I don't understand how they can do that. The cells in the battery pack are
> connected in series so the voltages are added together. How can the charger
> detect the voltage level of any "one" cell under these circumstances?
>


The charger is monitoring the total voltage of the pack (in series).
Once one cell peaks the voltage on that cell starts dropping rather
quickly as it warms up. Even if the rest of the cells are not peaked
yet the voltage increase of these cells cannot keep up with the drop
of the one fully charged cell; so there is a drop in the overall
voltage of the pack and the peak charger turns off. So you end up
with one cell slightly overcharged (not enough to damage it) and the
rest of the cells not fully charged. This is why the guys that race
electric vehicles spend so much money on matched cell packs, that way
all cells peak at the same time.

Rich

[Rhodesst]

Thanks, Rich!

I never realized that. Getting a battery pack with perfectly (or close to
that) matched cells sounds like a real pain. I imagine it would push the cost
up just a little.

Fly Safe,
Steve R.

>
>The charger is monitoring the total voltage of the pack (in series).
>Once one cell peaks the voltage on that cell starts dropping rather
>quickly as it warms up. Even if the rest of the cells are not peaked
>yet the voltage increase of these cells cannot keep up with the drop
>of the one fully charged cell; so there is a drop in the overall
>voltage of the pack and the peak charger turns off. So you end up
>with one cell slightly overcharged (not enough to damage it) and the
>rest of the cells not fully charged. This is why the guys that race
>electric vehicles spend so much money on matched cell packs, that way
>all cells peak at the same time.
>
>Rich

[Beav]

"Rhodesst" <rhodesst@aol.com> wrote in message
news:20030404211010.01769.00000372@mb-fk.aol.com...
> Thanks, Rich!
>
> I never realized that. Getting a battery pack with perfectly (or close to
> that) matched cells sounds like a real pain. I imagine it would push the
cost
> up just a little.

And you'd be right too Steve.

I've never found a need for matched cells for powering our Rx;s though.


--
Beav


Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk

[Carl Farrington]

"Rich Werth" <rwerth@ford.com> wrote in message
news:6ad99528.0304041225.575ff744@posting.google.c om...
> > I don't understand how they can do that. The cells in the battery pack
are
> > connected in series so the voltages are added together. How can the
charger
> > detect the voltage level of any "one" cell under these circumstances?
> >
>
>
> The charger is monitoring the total voltage of the pack (in series).
> Once one cell peaks the voltage on that cell starts dropping rather
> quickly as it warms up. Even if the rest of the cells are not peaked
> yet the voltage increase of these cells cannot keep up with the drop
> of the one fully charged cell; so there is a drop in the overall
> voltage of the pack and the peak charger turns off. So you end up
> with one cell slightly overcharged (not enough to damage it) and the
> rest of the cells not fully charged. This is why the guys that race
> electric vehicles spend so much money on matched cell packs, that way
> all cells peak at the same time.
>

So really what is needed is, say, an additional 5 core cable coming from the
pack, 1 wire for -ve and 4 individual wires connected to each cell, so that
the cells are charged independanty, but still simultaneously. Some kind of
gadgetery (magical diode type things?) would be needed in the pack to break
the series wiring whilst being charged.

Could be a market for a new type of battery pack & charger...

> Rich

[Carl Farrington]

"Carl Farrington" <carl@000compsup000.net> wrote in message
news:b6nrs7$hao$1$8300dec7@news.demon.co.uk...
> "Rich Werth" <rwerth@ford.com> wrote in message
> news:6ad99528.0304041225.575ff744@posting.google.c om...
>
> So really what is needed is, say, an additional 5 core cable coming from
the
> pack, 1 wire for -ve and 4 individual wires connected to each cell, so
that
> the cells are charged independanty, but still simultaneously. Some kind of
> gadgetery (magical diode type things?) would be needed in the pack to
break
> the series wiring whilst being charged.
>
> Could be a market for a new type of battery pack & charger...
>

Or how about this... the pack has slits in the covering/casing which are
in-line with the bases/tips of each cell. You basically drop the cell into a
'charging bay' which has contacts that slip in-between the cells to connect
each cell individually.

Charging then begins with peak detection independent on each cell

or some kind of variation on this theme

It might just work :)

(should I request a patent????? I have to be successful through something
and the lottery just doesn't seem to be happening 4 me)

[Mike]

> So really what is needed is, say, an additional 5 core cable coming from
>the
>> pack, 1 wire for -ve and 4 individual wires connected to each cell, so
>that
>> the cells are charged independanty, but still simultaneously. Some kind of
>> gadgetery (magical diode type things?) would be needed in the pack to
>break
>> the series wiring whilst being charged.
>>
>> Could be a market for a new type of battery pack & charger...
>>
>
>Or how about this... the pack has slits in the covering/casing which are
>in-line with the bases/tips of each cell. You basically drop the cell into a
>'charging bay' which has contacts that slip in-between the cells to connect
>each cell individually.
>
>Charging then begins with peak detection independent on each cell
>
>or some kind of variation on this theme
>
>It might just work :)
>
>(should I request a patent????? I have to be successful through something
>and the lottery just doesn't seem to be happening 4 me)
>
>
Brilliant idea.

Diodes would stop a fully charged cell from charging a partly charged cell. The
only problem I can see is that at some stage your 'independent' cells will need
to be connected together (and then broken apart again to charge). A switch or
switches could do it.

Cells obviously discharge at different rates too, so you could end up with a
pack that still had variations. Using the same principle, you would need some
gizmo to draw more current from the more fully charged cells.

Beyond me, but I'm sure someone could take it up, and it could be a major
advance in battery technology..who knows? You could email Sanyo, or even
Overlander, to see what they say.

[Carl Farrington]

"Mike" <mikespruce99@aol.comnospam> wrote in message
news:20030406170414.28413.00000353@mb-fl.aol.com...
> > So really what is needed is, say, an additional 5 core cable coming from
> >the
> >> pack, 1 wire for -ve and 4 individual wires connected to each cell, so
> >that
> >> the cells are charged independanty, but still simultaneously. Some kind
of
> >> gadgetery (magical diode type things?) would be needed in the pack to
> >break
> >> the series wiring whilst being charged.
> >>
> >> Could be a market for a new type of battery pack & charger...
> >>
> >
> >Or how about this... the pack has slits in the covering/casing which are
> >in-line with the bases/tips of each cell. You basically drop the cell
into a
> >'charging bay' which has contacts that slip in-between the cells to
connect
> >each cell individually.
> >
> >Charging then begins with peak detection independent on each cell
> >
> >or some kind of variation on this theme
> >
> >It might just work :)
> >
> >(should I request a patent????? I have to be successful through something
> >and the lottery just doesn't seem to be happening 4 me)
> >
> >
> Brilliant idea.
>
> Diodes would stop a fully charged cell from charging a partly charged
cell. The
> only problem I can see is that at some stage your 'independent' cells will
need
> to be connected together (and then broken apart again to charge). A switch
or
> switches could do it.
>
> Cells obviously discharge at different rates too, so you could end up with
a
> pack that still had variations. Using the same principle, you would need
some
> gizmo to draw more current from the more fully charged cells.
>
> Beyond me, but I'm sure someone could take it up, and it could be a major
> advance in battery technology..who knows? You could email Sanyo, or even
> Overlander, to see what they say.

Thanks Mike. I had a thought though - it wouldn't be any different to a
battery pack where the cells are simply in a holder - you know the spring
type battery pack.

Would it..?

cheers

Carl

[Mike]

>Thanks Mike. I had a thought though - it wouldn't be any different to a
>battery pack where the cells are simply in a holder - you know the spring
>type battery pack.
>
>Would it..?
>

I would guess no different at all, at least from the outside. The tricky bit
will be the wiring and associated switching, but this could all be built into
the 'case', so only the individual cells would see any redundancy, and could
therefore be replaced when useful life expired.

Being realistic it will probably be too costly and give only marginal benefits
to our receiver packs, but think about racing packs in top class electric car
racing circles, when they have to squeeze every last drop of performance out of
the batteries. Or even our own electric helicopters....