LiPo batteries versus NiMh batteries ...?

[Lighthawk Demon]

This question is in connection to my other question concerning RC
vehicles (cars/trucks)...I'm reading various articles and information
I'm finding around the Net and came across these new LiPo batteries
which seem to give the RC vehicles a bit of a boost and an extended
play time.Any RCers out there have experience with these new batteries
and if so how well do they work?Do you need to change the stock motor
in your vehicle to something a little more "beefier" to accomodate the
LiPo batteries, or do they increase the speed and play time just fine
with any motor?Thanks


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Lighthawk Demon


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[spartacus_nuc]

Lithium polymer batteries require a LiPo battery charger, and a speed
control with a LiPo cutoff, or an external LiPo cutoff. The reason for
this is that LiPo batteries will be damaged if the cell voltage drops
below 2.7V or goes above 4.2V or 4.3V. They will work fine with your
current motor, but it may seem a little more powerful because the
actual voltage doesn't drop as much while discharging (when you're
driving or accelerating hard), due to lower internal resistance of LiPo
batteries. Additionally, the nominal voltage of a 2 cell LiPo is 0.2V
higher than a 6 cell NiMH pack. The capacity is generally much higher
than a typical NiMH battery pack. I use Lipos, NiMHs and NiCds for
different types of radio control stuff. The LiPos are lighter, more
powerful, and last longer, but you MUST charge them properly and NEVER
over discharge them or they will be ruined, and possibly even catch on
fire. I use a MRC 977 pro and an Electrifly balancer for charging, and
I only use them with vehicles that have ESCs that can be configured for
LiPo and have an adjustable cutoff voltage to prevent over discharging.
If you're ready for something requiring a little more technical
expertise, LiPo batteries are the way to go. I am slowly converting
everything I've got to LiPo (over 25 RC vehicles between my wife and I)
as money allows. It's expensive, but worth it.


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spartacus_nuc


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Well said - all good information. However, I only use LIPOs only where
weight and/or space are concerns. For me, the advantages of LIPOs are not
great enough to justify the added cost and complexity in care and use.
Generally, I use NIMH packs for boats and LIPOs for aircraft.

Randy

"spartacus_nuc" <spartacus_nuc.3l4i61@no-mx.forums.yourdomain.com.au> wrote
in message news:spartacus_nuc.3l4i61@no-mx.forums.yourdomain.com.au...
>
> Lithium polymer batteries require a LiPo battery charger, and a speed
> control with a LiPo cutoff, or an external LiPo cutoff. The reason for
> this is that LiPo batteries will be damaged if the cell voltage drops
> below 2.7V or goes above 4.2V or 4.3V. They will work fine with your
> current motor, but it may seem a little more powerful because the
> actual voltage doesn't drop as much while discharging (when you're
> driving or accelerating hard), due to lower internal resistance of LiPo
> batteries. Additionally, the nominal voltage of a 2 cell LiPo is 0.2V
> higher than a 6 cell NiMH pack. The capacity is generally much higher
> than a typical NiMH battery pack. I use Lipos, NiMHs and NiCds for
> different types of radio control stuff. The LiPos are lighter, more
> powerful, and last longer, but you MUST charge them properly and NEVER
> over discharge them or they will be ruined, and possibly even catch on
> fire. I use a MRC 977 pro and an Electrifly balancer for charging, and
> I only use them with vehicles that have ESCs that can be configured for
> LiPo and have an adjustable cutoff voltage to prevent over discharging.
> If you're ready for something requiring a little more technical
> expertise, LiPo batteries are the way to go. I am slowly converting
> everything I've got to LiPo (over 25 RC vehicles between my wife and I)
> as money allows. It's expensive, but worth it.
>
>
> --
> spartacus_nuc
>
>
> ------------------------------------------------------------------------
> spartacus_nuc's Profile:
> http://www.modelpowerboat.com/forum/member.php?userid=6906
> View this thread:
> http://www.modelpowerboat.com/forum/showthread.php?t=1018
>

[frizo559@gmail.com]

On Dec 28, 6:16=A0am, spartacus_nuc <spartacus_nuc.3l4...@no-
mx.forums.yourdomain.com.au> wrote:
> Lithium polymer batteries require a LiPo battery charger, and a speed
> control with a LiPo cutoff, or an external LiPo cutoff. The reason for
> this is that LiPo batteries will be damaged if the cell voltage drops
> below 2.7V or goes above 4.2V or 4.3V. They will work fine with your
> current motor, but it may seem a little more powerful because the
> actual voltage doesn't drop as much while discharging (when you're
> driving or accelerating hard), due to lower internal resistance of LiPo
> batteries. Additionally, the nominal voltage of a =A02 cell LiPo is 0.2V
> higher than a 6 cell NiMH pack. The capacity is generally much higher
> than a typical NiMH battery pack. I use Lipos, NiMHs and NiCds for
> different types of radio control stuff. The LiPos are lighter, more
> powerful, and last longer, but you MUST charge them properly and NEVER
> over discharge them or they will be ruined, and possibly even catch on
> fire. I use a MRC 977 pro and an Electrifly balancer for charging, and
> I only use them with vehicles that have ESCs that can be configured for
> LiPo and have an adjustable cutoff voltage to prevent over discharging.
> If you're ready for something requiring a little more technical
> expertise, LiPo batteries are the way to go. I am slowly converting
> everything I've got to LiPo (over 25 RC vehicles between my wife and I)
> as money allows. It's expensive, but worth it.

Ok I have a ? I just purchased an MRC 977 pro and it specifically
states to NOT use on lipo batteries... I am just in to changing from
nihm to lipo. And I just got this charger... I am not sure its wise to
use this with lipo batteries????

also the electrify balancer( is this it? http://www.electrifly.com/charge=
rs/gpmm3160.html

great idea but what about this???
http://www.robotmarketplace.com/products/0-AST106.html
and what about having old esc boards with out the 3 volt check thingy,
what do i buy to take care of that????
anyway... I need some answers before moving onto my finished project
( homepage.mac.com/noall666)
check it out if you like...
hope to get some replys, would love to not have to buy new charger????
later

[frizo559@gmail.com]

On Dec 28, 11:20=A0am, <rmahe...@bellsouth.net> wrote:
> Well said - all good information. =A0However, I only use LIPOs only where
> weight and/or space are concerns. =A0For me, the advantages of LIPOs are =
not
> great enough to justify the added cost and complexity in care and use.
> Generally, I use NIMH packs for boats and LIPOs for aircraft.
>
> Randy
>
> "spartacus_nuc" <spartacus_nuc.3l4...@no-mx.forums.yourdomain.com.au> wro=
te
> in messagenews:spartacus_nuc.3l4i61@no-mx.forums.yourdomain.com.au...
>
>
>
> > Lithium polymer batteries require a LiPo battery charger, and a speed
> > control with a LiPo cutoff, or an external LiPo cutoff. The reason for
> > this is that LiPo batteries will be damaged if the cell voltage drops
> > below 2.7V or goes above 4.2V or 4.3V. They will work fine with your
> > current motor, but it may seem a little more powerful because the
> > actual voltage doesn't drop as much while discharging (when you're
> > driving or accelerating hard), due to lower internal resistance of LiPo
> > batteries. Additionally, the nominal voltage of a =A02 cell LiPo is 0.2=
V
> > higher than a 6 cell NiMH pack. The capacity is generally much higher
> > than a typical NiMH battery pack. I use Lipos, NiMHs and NiCds for
> > different types of radio control stuff. The LiPos are lighter, more
> > powerful, and last longer, but you MUST charge them properly and NEVER
> > over discharge them or they will be ruined, and possibly even catch on
> > fire. I use a MRC 977 pro and an Electrifly balancer for charging, and
> > I only use them with vehicles that have ESCs that can be configured for
> > LiPo and have an adjustable cutoff voltage to prevent over discharging.
> > If you're ready for something requiring a little more technical
> > expertise, LiPo batteries are the way to go. I am slowly converting
> > everything I've got to LiPo (over 25 RC vehicles between my wife and I)
> > as money allows. It's expensive, but worth it