hovercraft

[B Frey]

I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V battery pack
when I bought it.

The problem is that the power only lasts for about 5 minutes...

- is it possible to use a more powerful battery pack?
- it is the mAh that should be higher, right?
- how big can you get those battery packs?
- I have seen that you can also get a NiMh battery pack - what is the
difference?
Can I use both NiCd and NiMh in for the hovercraft?

- What would you suggest?

Hoping for help :-)
thanks..
B Frey

[Colin Dawson]

"B Frey" <musik@paradis.dk> wrote in message
news:4127017a$0$201$edfadb0f@dread12.news.tele.dk. ..
>I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V battery pack
> when I bought it.
>
> The problem is that the power only lasts for about 5 minutes...
>
> - is it possible to use a more powerful battery pack?
> - it is the mAh that should be higher, right?
> - how big can you get those battery packs?
> - I have seen that you can also get a NiMh battery pack - what is the
> difference?
> Can I use both NiCd and NiMh in for the hovercraft?
>
> - What would you suggest?
>
> Hoping for help :-)
> thanks..
> B Frey
>
>

Hi.

I'm no expert in modelling battery packs, but I think I can help a
little....

1. it depends on what you mean be more power - higher voltage with run your
motors harder, giving them a speed boost. There's always the risk of
overheating things though so be careful not to raise it too far. On the
other hand if your talking about longer running time, that's a different
story....

2. Increasing the mAh will increase the running time, the more power stored
in the battery the longer it'll take to drain.

3. I've got some AA's that hold 2300 mA. That should give you some idea.

4. The difference between NiCad and NiMh is the chemicals used in
construction. In real terms, NiCad's have a problem known as the Memory
Effect, which will degrade the performance of the battery over time. After
a while you won't be able to put a full charge into the battery, shortening
the running time. This problem can get so bad that it's impossible to
charge the battery.

NiMh batteries as alot better in that the memory effect is not as bad.
Contry to popular belief there is still a memory effect in these batteries,
but it's so small that it's hardly worth noting. I'm not sure, but I also
think that they're capable of delivering more power. In short NiMh's are
alot better than NiCad's.

Regards

Colin Dawson
www.cjdawson.com

[B Frey]

Thanks for the answers.

So you think I can buy a 2300 mAh NiMh battery and use it instead of the
NiCad battery I got with the hovercraft?
If NiCad batteries are poor why do they sell them with the hovercraft? -
because they are cheap?

Regards
B Frey

"Colin Dawson" <nospam@cjdawson.com> skrev i en meddelelse
news:cg72i4$guk$1@sparta.btinternet.com...
>
> "B Frey" <musik@paradis.dk> wrote in message
> news:4127017a$0$201$edfadb0f@dread12.news.tele.dk. ..
> >I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V battery pack
> > when I bought it.
> >
> > The problem is that the power only lasts for about 5 minutes...
> >
> > - is it possible to use a more powerful battery pack?
> > - it is the mAh that should be higher, right?
> > - how big can you get those battery packs?
> > - I have seen that you can also get a NiMh battery pack - what is the
> > difference?
> > Can I use both NiCd and NiMh in for the hovercraft?
> >
> > - What would you suggest?
> >
> > Hoping for help :-)
> > thanks..
> > B Frey
> >
> >
>
> Hi.
>
> I'm no expert in modelling battery packs, but I think I can help a
> little....
>
> 1. it depends on what you mean be more power - higher voltage with run
your
> motors harder, giving them a speed boost. There's always the risk of
> overheating things though so be careful not to raise it too far. On the
> other hand if your talking about longer running time, that's a different
> story....
>
> 2. Increasing the mAh will increase the running time, the more power
stored
> in the battery the longer it'll take to drain.
>
> 3. I've got some AA's that hold 2300 mA. That should give you some idea.
>
> 4. The difference between NiCad and NiMh is the chemicals used in
> construction. In real terms, NiCad's have a problem known as the Memory
> Effect, which will degrade the performance of the battery over time.
After
> a while you won't be able to put a full charge into the battery,
shortening
> the running time. This problem can get so bad that it's impossible to
> charge the battery.
>
> NiMh batteries as alot better in that the memory effect is not as bad.
> Contry to popular belief there is still a memory effect in these
batteries,
> but it's so small that it's hardly worth noting. I'm not sure, but I also
> think that they're capable of delivering more power. In short NiMh's are
> alot better than NiCad's.
>
> Regards
>
> Colin Dawson
> www.cjdawson.com
>
>

[Kevin R]

if its just a longer run time you after go for NiMh they have a better
capacity for the same size but the initial power(current) is less than a
NiCad but the power level remains more or less constant I believe its down
to a high internal resistance of a NiMh cell which limits the maximum
current , the initial power high from a NiCad drops off to a level roughly
the same a NiMh, I have a set of NiMh batteries in a plane the performance
is double or I could have used a battery that's nearly half the weight
"B Frey" <musik@paradis.dk> wrote in message
news:4127132a$0$216$edfadb0f@dread12.news.tele.dk. ..
> Thanks for the answers.
>
> So you think I can buy a 2300 mAh NiMh battery and use it instead of the
> NiCad battery I got with the hovercraft?
> If NiCad batteries are poor why do they sell them with the hovercraft? -
> because they are cheap?
>
> Regards
> B Frey
>
> "Colin Dawson" <nospam@cjdawson.com> skrev i en meddelelse
> news:cg72i4$guk$1@sparta.btinternet.com...
> >
> > "B Frey" <musik@paradis.dk> wrote in message
> > news:4127017a$0$201$edfadb0f@dread12.news.tele.dk. ..
> > >I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V battery
pack
> > > when I bought it.
> > >
> > > The problem is that the power only lasts for about 5 minutes...
> > >
> > > - is it possible to use a more powerful battery pack?
> > > - it is the mAh that should be higher, right?
> > > - how big can you get those battery packs?
> > > - I have seen that you can also get a NiMh battery pack - what is the
> > > difference?
> > > Can I use both NiCd and NiMh in for the hovercraft?
> > >
> > > - What would you suggest?
> > >
> > > Hoping for help :-)
> > > thanks..
> > > B Frey
> > >
> > >
> >
> > Hi.
> >
> > I'm no expert in modelling battery packs, but I think I can help a
> > little....
> >
> > 1. it depends on what you mean be more power - higher voltage with run
> your
> > motors harder, giving them a speed boost. There's always the risk of
> > overheating things though so be careful not to raise it too far. On the
> > other hand if your talking about longer running time, that's a different
> > story....
> >
> > 2. Increasing the mAh will increase the running time, the more power
> stored
> > in the battery the longer it'll take to drain.
> >
> > 3. I've got some AA's that hold 2300 mA. That should give you some idea.
> >
> > 4. The difference between NiCad and NiMh is the chemicals used in
> > construction. In real terms, NiCad's have a problem known as the Memory
> > Effect, which will degrade the performance of the battery over time.
> After
> > a while you won't be able to put a full charge into the battery,
> shortening
> > the running time. This problem can get so bad that it's impossible to
> > charge the battery.
> >
> > NiMh batteries as alot better in that the memory effect is not as bad.
> > Contry to popular belief there is still a memory effect in these
> batteries,
> > but it's so small that it's hardly worth noting. I'm not sure, but I
also
> > think that they're capable of delivering more power. In short NiMh's
are
> > alot better than NiCad's.
> >
> > Regards
> >
> > Colin Dawson
> > www.cjdawson.com
> >
> >
>
>

[B Frey]

Okay - thanks.

Now the final question.

I have a 700 mAh NiCad battery pack (8x AA 9.6V).
The run time of the hovercraft is about 6 min with those batteries.

I have found two battery types:
- 900 mAh NiCad
- 2300 mAh NiMh

Does anyone have any idea how much the run time will be with those types?

Which batteri would you suggest?

Thanks
B Frey



"Kevin R" <dontemailme@ntlworld.com> skrev i en meddelelse
news:VgGVc.233$GZ2.61@newsfe4-gui.ntli.net...
> if its just a longer run time you after go for NiMh they have a better
> capacity for the same size but the initial power(current) is less than a
> NiCad but the power level remains more or less constant I believe its down
> to a high internal resistance of a NiMh cell which limits the maximum
> current , the initial power high from a NiCad drops off to a level roughly
> the same a NiMh, I have a set of NiMh batteries in a plane the performance
> is double or I could have used a battery that's nearly half the weight
> "B Frey" <musik@paradis.dk> wrote in message
> news:4127132a$0$216$edfadb0f@dread12.news.tele.dk. ..
> > Thanks for the answers.
> >
> > So you think I can buy a 2300 mAh NiMh battery and use it instead of the
> > NiCad battery I got with the hovercraft?
> > If NiCad batteries are poor why do they sell them with the hovercraft? -
> > because they are cheap?
> >
> > Regards
> > B Frey
> >
> > "Colin Dawson" <nospam@cjdawson.com> skrev i en meddelelse
> > news:cg72i4$guk$1@sparta.btinternet.com...
> > >
> > > "B Frey" <musik@paradis.dk> wrote in message
> > > news:4127017a$0$201$edfadb0f@dread12.news.tele.dk. ..
> > > >I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V battery
> pack
> > > > when I bought it.
> > > >
> > > > The problem is that the power only lasts for about 5 minutes...
> > > >
> > > > - is it possible to use a more powerful battery pack?
> > > > - it is the mAh that should be higher, right?
> > > > - how big can you get those battery packs?
> > > > - I have seen that you can also get a NiMh battery pack - what is
the
> > > > difference?
> > > > Can I use both NiCd and NiMh in for the hovercraft?
> > > >
> > > > - What would you suggest?
> > > >
> > > > Hoping for help :-)
> > > > thanks..
> > > > B Frey
> > > >
> > > >
> > >
> > > Hi.
> > >
> > > I'm no expert in modelling battery packs, but I think I can help a
> > > little....
> > >
> > > 1. it depends on what you mean be more power - higher voltage with run
> > your
> > > motors harder, giving them a speed boost. There's always the risk of
> > > overheating things though so be careful not to raise it too far. On
the
> > > other hand if your talking about longer running time, that's a
different
> > > story....
> > >
> > > 2. Increasing the mAh will increase the running time, the more power
> > stored
> > > in the battery the longer it'll take to drain.
> > >
> > > 3. I've got some AA's that hold 2300 mA. That should give you some
idea.
> > >
> > > 4. The difference between NiCad and NiMh is the chemicals used in
> > > construction. In real terms, NiCad's have a problem known as the
Memory
> > > Effect, which will degrade the performance of the battery over time.
> > After
> > > a while you won't be able to put a full charge into the battery,
> > shortening
> > > the running time. This problem can get so bad that it's impossible to
> > > charge the battery.
> > >
> > > NiMh batteries as alot better in that the memory effect is not as
bad.
> > > Contry to popular belief there is still a memory effect in these
> > batteries,
> > > but it's so small that it's hardly worth noting. I'm not sure, but I
> also
> > > think that they're capable of delivering more power. In short NiMh's
> are
> > > alot better than NiCad's.
> > >
> > > Regards
> > >
> > > Colin Dawson
> > > www.cjdawson.com
> > >
> > >
> >
> >
>
>

[Colin Dawson]

"B Frey" <musik@paradis.dk> wrote in message
news:4127132a$0$216$edfadb0f@dread12.news.tele.dk. ..
> Thanks for the answers.
>
> So you think I can buy a 2300 mAh NiMh battery and use it instead of the
> NiCad battery I got with the hovercraft?
> If NiCad batteries are poor why do they sell them with the hovercraft? -
> because they are cheap?
>
> Regards
> B Frey
>

I just bought a Ni-MH 1850mA pack (5 Cell). So I know these are available.
The 2300 are standard AA type, which I use in my Digital Camera.

Ni Cad's are cheaper to produce and easily available. Ni-MH are normally
sold in Electrical shops as opposed to your local hypermarket.

Regards

Colin Dawson
www.cjdawson.com

[Kevin R]

forget the NiCad 200ma will only give you 2 mins extra possibly, go for the
NiMh and looking at the rate on your old battery 20 mins run on the NiMh ,as
long as they are high current cells that is ,as your are looking at about 5
or 6 amps discharge current to flatten a 700mah in 6 minutes you will need a
battery that will stand that current drain
Kevin
"B Frey" <musik@paradis.dk> wrote in message
news:41272739$0$221$edfadb0f@dread12.news.tele.dk. ..
> Okay - thanks.
>
> Now the final question.
>
> I have a 700 mAh NiCad battery pack (8x AA 9.6V).
> The run time of the hovercraft is about 6 min with those batteries.
>
> I have found two battery types:
> - 900 mAh NiCad
> - 2300 mAh NiMh
>
> Does anyone have any idea how much the run time will be with those types?
>
> Which batteri would you suggest?
>
> Thanks
> B Frey
>
>
>
> "Kevin R" <dontemailme@ntlworld.com> skrev i en meddelelse
> news:VgGVc.233$GZ2.61@newsfe4-gui.ntli.net...
> > if its just a longer run time you after go for NiMh they have a better
> > capacity for the same size but the initial power(current) is less than
a
> > NiCad but the power level remains more or less constant I believe its
down
> > to a high internal resistance of a NiMh cell which limits the maximum
> > current , the initial power high from a NiCad drops off to a level
roughly
> > the same a NiMh, I have a set of NiMh batteries in a plane the
performance
> > is double or I could have used a battery that's nearly half the weight
> > "B Frey" <musik@paradis.dk> wrote in message
> > news:4127132a$0$216$edfadb0f@dread12.news.tele.dk. ..
> > > Thanks for the answers.
> > >
> > > So you think I can buy a 2300 mAh NiMh battery and use it instead of
the
> > > NiCad battery I got with the hovercraft?
> > > If NiCad batteries are poor why do they sell them with the
hovercraft? -
> > > because they are cheap?
> > >
> > > Regards
> > > B Frey
> > >
> > > "Colin Dawson" <nospam@cjdawson.com> skrev i en meddelelse
> > > news:cg72i4$guk$1@sparta.btinternet.com...
> > > >
> > > > "B Frey" <musik@paradis.dk> wrote in message
> > > > news:4127017a$0$201$edfadb0f@dread12.news.tele.dk. ..
> > > > >I have a R/C hovercraft and I got a NiCd (8x)AA 700 mAh 9.6V
battery
> > pack
> > > > > when I bought it.
> > > > >
> > > > > The problem is that the power only lasts for about 5 minutes...
> > > > >
> > > > > - is it possible to use a more powerful battery pack?
> > > > > - it is the mAh that should be higher, right?
> > > > > - how big can you get those battery packs?
> > > > > - I have seen that you can also get a NiMh battery pack - what is
> the
> > > > > difference?
> > > > > Can I use both NiCd and NiMh in for the hovercraft?
> > > > >
> > > > > - What would you suggest?
> > > > >
> > > > > Hoping for help :-)
> > > > > thanks..
> > > > > B Frey
> > > > >
> > > > >
> > > >
> > > > Hi.
> > > >
> > > > I'm no expert in modelling battery packs, but I think I can help a
> > > > little....
> > > >
> > > > 1. it depends on what you mean be more power - higher voltage with
run
> > > your
> > > > motors harder, giving them a speed boost. There's always the risk
of
> > > > overheating things though so be careful not to raise it too far. On
> the
> > > > other hand if your talking about longer running time, that's a
> different
> > > > story....
> > > >
> > > > 2. Increasing the mAh will increase the running time, the more power
> > > stored
> > > > in the battery the longer it'll take to drain.
> > > >
> > > > 3. I've got some AA's that hold 2300 mA. That should give you some
> idea.
> > > >
> > > > 4. The difference between NiCad and NiMh is the chemicals used in
> > > > construction. In real terms, NiCad's have a problem known as the
> Memory
> > > > Effect, which will degrade the performance of the battery over time.
> > > After
> > > > a while you won't be able to put a full charge into the battery,
> > > shortening
> > > > the running time. This problem can get so bad that it's impossible
to
> > > > charge the battery.
> > > >
> > > > NiMh batteries as alot better in that the memory effect is not as
> bad.
> > > > Contry to popular belief there is still a memory effect in these
> > > batteries,
> > > > but it's so small that it's hardly worth noting. I'm not sure, but
I
> > also
> > > > think that they're capable of delivering more power. In short
NiMh's
> > are
> > > > alot better than NiCad's.
> > > >
> > > > Regards
> > > >
> > > > Colin Dawson
> > > > www.cjdawson.com
> > > >
> > > >
> > >
> > >
> >
> >
>
>

[Colin Dawson]

"Kevin R" <dontemailme@ntlworld.com> wrote in message
news:BTGVc.337$GZ2.152@newsfe4-gui.ntli.net...
> forget the NiCad 200ma will only give you 2 mins extra possibly, go for
> the
> NiMh and looking at the rate on your old battery 20 mins run on the NiMh
> ,as
> long as they are high current cells that is ,as your are looking at about
> 5
> or 6 amps discharge current to flatten a 700mah in 6 minutes you will need
> a
> battery that will stand that current drain
> Kevin


I'll second that. I've not heard about the discharge current limit before,
it's worth checking out if possible. If the batteries arn't up to it, either
your hovercraft won't run right, or something will go bang. More than
likely everything will be OK though as rechargables are supposed to be
better for high current applications.

Regards

Colin Dawson
www.cjdawson.com