Battery 6ah vs. more

On Apr 23, 9:11 am, Herb wrote:
On Apr 23, 1:56 am, nimbusgb wrote:



On 22 Apr, 14:13, "kirk.stant" wrote:

Buy the biggest you can fit!

Powersonic has a 9 AH in same format as 7.2

Then add more batteries, they are cheap, lost instruments are
dangerous, lost OLC logs are maddening!

From experience.... now running 3 batteries..... saves me adding water
ballast! ;-)

Bob

AMEN!

My solution was to split the cockpit into two electrical busses, each
with it's own 9AH battery. Either side can fail and I have enough
"stuff" to get home (or finish a race...). Can also gang the busses
so either battery can power all the cockpit.

I have 3 batteries, one is always on the charger, and rotate the ones
from the flight every evening - so I always have 2 fully charged
batteries every flight. No special connectors on the batteries, so
any standard size 7 - 9 AH "brick" with spade connectors will fit, if
necessary.

It's worked so far (8 years and counting...).

I see there are some new technology batteries coming on the market for
gliders (in S&G?) - maybe we are about to move on from our beloved
lead bricks!

Kirk
66

I replaced my lead acid 7 ah brick with a NiMh pack made up by a
supplier. The result is a pack that fits into the same battery holder
slot, is 30% lower in height, 50% lighter, runs at 14v nominal and
has a 9 Ah capacity. It was so succesfull that I replaced the second
15 ah battery used to raise and lower the turbo with a similar pack
but of only 12ah but saving 7kg.

One other advantage is that they use a purpose built microprocessor
controlled charger that ensures they are fully charged and ready to go
even when left permanently connected.

Same here, 10Ah NiMh battery dedicated to the transponder, two 5Ah
packs for the instruments (one in the tail). Charger is putting out
2A and takes only about 2-4h after a normal day of flying to replenish
the batteries. I built the packs myself from cells with tabs and paid
only $80 for the large 10Ah pack, half of that for each of the small
ones. No more lead-acid batteries! The weight savings mentioned by
nimbusgb might be a bit aggressive, I'd say NiMh is about 60% lighter
than the same lead-acid capacity battery.
Herb

I have four batteries and like lead for the extra weight. Higher wing
loading is good out west!

Mike

I'd love to see some pictures of your NiMh creations.

Can you send to me or upload somewhere like http://www.flickr.com.

This would also be a great how to article for Soaring.

john at derosaweb.com

Thanks

On 23 Apr, 16:11, Herb wrote:
On Apr 23, 1:56 am, nimbusgb wrote:



On 22 Apr, 14:13, "kirk.stant" wrote:

Buy the biggest you can fit!

Powersonic has a 9 AH in same format as 7.2

Then add more batteries, they are cheap, lost instruments are
dangerous, lost OLC logs are maddening!

From experience.... now running 3 batteries..... saves me adding water
ballast! ;-)

Bob

AMEN!

My solution was to split the cockpit into two electrical busses, each
with it's own 9AH battery. Either side can fail and I have enough
"stuff" to get home (or finish a race...). Can also gang the busses
so either battery can power all the cockpit.

I have 3 batteries, one is always on the charger, and rotate the ones
from the flight every evening - so I always have 2 fully charged
batteries every flight. No special connectors on the batteries, so
any standard size 7 - 9 AH "brick" with spade connectors will fit, if
necessary.

It's worked so far (8 years and counting...).

I see there are some new technology batteries coming on the market for
gliders (in S&G?) - maybe we are about to move on from our beloved
lead bricks!

Kirk
66

I replaced my lead acid 7 ah brick with a NiMh pack made up by a
supplier. The result is a pack that fits into the same battery holder
slot, is 30% lower in height, 50% lighter, runs at 14v nominal and
has a 9 Ah capacity. It was so succesfull that I replaced the second
15 ah battery used to raise and lower the turbo with a similar pack
but of only 12ah but saving 7kg.

One other advantage is that they use a purpose built microprocessor
controlled charger that ensures they are fully charged and ready to go
even when left permanently connected.

Same here, 10Ah NiMh battery dedicated to the transponder, two 5Ah
packs for the instruments (one in the tail). Charger is putting out
2A and takes only about 2-4h after a normal day of flying to replenish
the batteries. I built the packs myself from cells with tabs and paid
only $80 for the large 10Ah pack, half of that for each of the small
ones. No more lead-acid batteries! The weight savings mentioned by
nimbusgb might be a bit aggressive, I'd say NiMh is about 60% lighter
than the same lead-acid capacity battery.
Herb

Sorry not 7kg but 7lb lighter than the big 18Ah (?) pack.I agree about
60% of the weight of the lead acids.

Ian

On 24 Apr, 11:20, ContestID67 wrote:
I'd love to see some pictures of your NiMh creations.

Can you send to me or upload somewhere likehttp://www.flickr.com.

This would also be a great how to article for Soaring.

john at derosaweb.com

Thanks

Just as a matter of interest .....

I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.

Ian

On Apr 24, 9:58*am, nimbusgb wrote:
On 24 Apr, 11:20, ContestID67 wrote:

I'd love to see some pictures of your NiMh creations.

Can you send to me or upload somewhere likehttp://www.flickr.com.

This would also be a great how to article for Soaring.

john at derosaweb.com

Thanks

Just as a matter of interest .....

I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.

Ian

I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.

wrote:
On Apr 24, 9:58 am, nimbusgb wrote:

I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.

Ian

I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.

You don't fly with a cell phone or a PDA?

Marc

On Apr 24, 12:30*pm, Marc Ramsey wrote:
wrote:
On Apr 24, 9:58 am, nimbusgb wrote:

I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.

Ian

I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.

You don't fly with a cell phone or a PDA?

Marc

Not with lithium Polymer batteries. Lithium Ion, yes. Lithium
Polymer, no.

On Apr 24, 12:30*pm, Marc Ramsey wrote:
wrote:
On Apr 24, 9:58 am, nimbusgb wrote:

I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.

Ian

I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.

You don't fly with a cell phone or a PDA?

Marc

Have you ever seen an R/C LiPo cell? No hard case. It is essentially
a tin-foil-like bag of chemicals with a very high energy density.

wrote:
On Apr 24, 12:30 pm, Marc Ramsey wrote:
wrote:
On Apr 24, 9:58 am, nimbusgb wrote:
I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.
Ian
I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.
You don't fly with a cell phone or a PDA?

Marc

Not with lithium Polymer batteries. Lithium Ion, yes. Lithium
Polymer, no.


What makes you think the "lithium ion" cells used in PDAs, laptops, and
cellphones are any different than the "lithium polymer" cells used in
R/C aircraft? Have you ever looked at the cells inside a PDA, or inside
the plastic cases used for cellphone or laptop batteries? Nearly all
are lithium polymer these days (and the R/C suppliers get theirs from
the same factories, which is why they are relatively cheap), although
the laptop manufacturers, thanks to some rather public incidents, are
just starting to switch over to newer, somewhat less flammable, battery
chemistries...

Marc

On Apr 24, 1:17*pm, Marc Ramsey wrote:
wrote:
On Apr 24, 12:30 pm, Marc Ramsey wrote:
wrote:
On Apr 24, 9:58 am, nimbusgb wrote:
I am flying OPA's at the moment ( other peoples aeroplanes ) and have
a portable setup with Colibri logger and Ipaq PDA all driven from a
LiPo Electric R/C aircraft flight pack. A12v pack with 2200ma/hr
capacity. The power to volume/weight ratio is great. The pack weighs
about 100g and is about the size of 6 cigarettes! It drives the setup
for about 6 hours with the pda on all the time.
Ian
I would never fly with LiPo on board. Let alone in someone elses ship.
I have quite a few of them for my R/C aircraft and have seen them at
their worst. Please be careful.
You don't fly with a cell phone or a PDA?

Marc

Not with lithium Polymer batteries. Lithium Ion, yes. *Lithium
Polymer, no.

What makes you think the "lithium ion" cells used in PDAs, laptops, and
cellphones are any different than the "lithium polymer" cells used in
R/C aircraft? *Have you ever looked at the cells inside a PDA, or inside
the plastic cases used for cellphone or laptop batteries? *Nearly all
are lithium polymer these days (and the R/C suppliers get theirs from
the same factories, which is why they are relatively cheap), although
the laptop manufacturers, thanks to some rather public incidents, are
just starting to switch over to newer, somewhat less flammable, battery
chemistries...

Marc- Hide quoted text -

- Show quoted text -

Sorry, didn't mean to start an argument. Maybe my caution regarding
flying with R/C (foil bag) LiPo batteries is a little over the top. I
can live with erring on the side of caution. To each his own.