NIMH Batteries

[K M]

Dear List,
It is time to replace one of the battery packs for my sailplane. I
currently use packs consisting of 7 2.5V SLA batteries to make a 14V
pack. This has worked very well for me in the past but the AH on these
cells is somewhat limited. I would like to ad a transponder and
possibly some type of collision avoidance device so I am looking to
upgrade the power supply. I have seen Nickel Metal Hydrate batteries
that come in 12V and 10 to 14 AH sized the same as the SLA batteries
alot of the glider people are using. There is a company in the UK ,
ATSI, who markets these NIMH batteries for aviation use. My question
is does anyone on the list have any experience with these or any other
12V NIMH batteries for glider use. I dont mind using the sealed lead
acid batteries but the NIMH has many advantages . And yea, I know
price isnt one of them.
Thanks

[sisu1a]

I dont mind using the sealed lead
> acid batteries but the NIMH has many advantages . And yea, I know
> price isnt one of them.
> Thanks

NIMH?!? If cost doesn't frighten you, then why not LiFePO4?
http://www.valence.com/products/battery_modules/u-charge_xp
http://www.valence.com/sites/all/themes/valence/pdfs/U-Charge%20XP%20Data%20Sheet.pdf
http://www.valence.com/products/battery_modules/u-charge_rt
(integrated battery maintenance version...)
http://www.valence.com/sites/all/themes/valence/pdfs/U-Charge%20RT%20Data%20Sheet.pdf
Kick a$$ batteries with 1/4-20 threaded connections to boot...but
certainly not cheap. Just talked to a nice lady there at Valence, and
for reference:

40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
12v 12 amp/hr lead brick but half the weight)
24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
built in battery management system)
Both series are claimed to be able to be charged on most standard lead
acid chargers (set for AGM/GEL cells)

-Paul

[K M]

On Dec 4, 12:45*pm, sisu1a > wrote:

>
> *40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
> 12v 12 amp/hr lead brick but half the weight)
> *24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
> built in battery management system)
> Both series are claimed to be able to be charged on most standard lead
> acid chargers (set for AGM/GEL cells)
>
> -Paul

Paul, thanks for the links, I never knew these existed . If one can
actually get "Thousands of cycles" then these would be much more
affordable than the steep initial cost might sugest. Have you been
using one in your plane ?
Thanks

[Darryl Ramm]

On Dec 4, 11:11*am, K M > wrote:
> Dear List,
> It is time to replace one of the battery packs for my sailplane. I
> currently use packs consisting of 7 2.5V SLA batteries to make a 14V
> pack. This has worked very well for me in the past but the AH on these
> cells is somewhat limited. I would like to ad a transponder and
> possibly some type of collision avoidance device so I am looking to
> upgrade the power supply. I have seen Nickel Metal Hydrate batteries
> that come in 12V and 10 to 14 AH sized the same as the SLA batteries
> alot of the glider people are using. There is a company in the UK ,
> ATSI, who markets these NIMH batteries for aviation use. My question
> is does anyone on the list have any experience with these or any other
> 12V NIMH batteries for glider use. I dont mind using the sealed lead
> acid batteries but the NIMH has many advantages . And yea, I know
> price isnt one of them.
> Thanks

I assume the reason you hand made a 7 cell SLA battery is you needed
the higher voltage for some fussy electronics? Modern electronics
should work fine on the voltages output from a conventional 6 cell SLA
battery - of course until the voltage falls below a critical point.
Was there a particular device that needed the higher voltage? Without
that need just using that volume to accommodate extra battery capacity
and a standard 6 cell battery will be easier and cheaper. Of course
another reason might just be you have strange space requirements and
fitting in 7 cells of a particular size was the best way to go.

If you have got voltage sensitive equipment NiMH offers the benefit of
a flatter discharge curve than lead-acid (in addition obviously to
more Ah/volume). Of course that can also bite in making it less
obvious what the remaining battery capacity is.

Darryl

[Uncle Fuzzy]

On Dec 4, 12:02*pm, K M > wrote:
> On Dec 4, 12:45*pm, sisu1a > wrote:
>
>
>
> > *40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
> > 12v 12 amp/hr lead brick but half the weight)
> > *24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
> > built in battery management system)
> > Both series are claimed to be able to be charged on most standard lead
> > acid chargers (set for AGM/GEL cells)
>
> > -Paul
>
> Paul, thanks for the links, I never knew these existed . If one can
> actually get "Thousands of cycles" then these would be much more
> affordable than the steep initial cost might sugest. Have you been
> using one in your plane ?
> Thanks

If you could live long enough to utilize even a thousand cycles,
maybe. I get 4 years service from my 14 volt (10 ah 2v glued to 10 ah
12v) pack, for around $80.00. To meet the same $/yr figure I'd have
to fly another 30years, which is unlikely.

[Mike[_8_]]

On Dec 4, 12:11*pm, K M > wrote:
> Dear List,
I have been thinking of using 10 of these 10,000 mAh NiMH batteries
for a separate transponder circuit in my sailplane. Light weight, 1000
cycles and only moderately expensive. Use 10 or 12 depending upon your
needs. Packs and connectors are easy to fabricate.

http://www.all-battery.com/dsizeseriesnimhrechargeablebatteries.aspx

I have one of their 3200 mAh pre-made packs and capacity was as
advertised.



> It is time to replace one of the battery packs for my sailplane. I
> currently use packs consisting of 7 2.5V SLA batteries to make a 14V
> pack. This has worked very well for me in the past but the AH on these
> cells is somewhat limited. I would like to ad a transponder and
> possibly some type of collision avoidance device so I am looking to
> upgrade the power supply. I have seen Nickel Metal Hydrate batteries
> that come in 12V and 10 to 14 AH sized the same as the SLA batteries
> alot of the glider people are using. There is a company in the UK ,
> ATSI, who markets these NIMH batteries for aviation use. My question
> is does anyone on the list have any experience with these or any other
> 12V NIMH batteries for glider use. I dont mind using the sealed lead
> acid batteries but the NIMH has many advantages . And yea, I know
> price isnt one of them.
> Thanks

[Tuno]

Would that be 100,000 mAh?

Sounds like a lot but maybe not for a glider with a 15000 mm wingspan.

2NO

[Andy[_1_]]

On Dec 4, 2:07*pm, Tuno > wrote:
> Would that be 100,000 mAh?

10 cells of 10,000mAh capacity in series is still 10,000mAh capacity.
Only the voltage increases. I don't know why the spec is in mAh
instead of Ah, perhaps because the capacity of D type cells used to be
less than 1Ah?

Andy

[Martin Gregorie[_4_]]

Slightly hijacking this thread:

Can anybody recommend a reliable manufacturer of NiMH batteries.

I've tried a variety of makes of 2 - 2.4 Ah AA cells for running digital
cameras and have to say I'm far from impressed.

I have two good chargers (a Vencon which is mains driven and controlled
by a PC and a Pro-Peak Prodigy II which runs off 12v and designed for
field charging RC aircraft batteries). Both are peak chargers and can
record the mAh during charge and test discharge.

I've yet to try a NiMH brand that comes near its rated capacity. Most
show an, ahem, spectacular drop in capacity during subsequent cycles.

I've never had any of this nonsense from NiCd cells: they 'just
work' (unless made by GP).

Bottom line: unless I can find a brand of NiMH that does what it says on
the tin there's no way I'm going to spend good money on using them to
replace SLAs or trust them to last out a decent xc flight.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Andy[_1_]]

On Dec 4, 3:21*pm, Martin Gregorie
> wrote:
> Slightly hijacking this thread:
>
> Can anybody recommend a reliable manufacturer of NiMH batteries.
>
> I've tried a variety of makes of 2 - 2.4 Ah AA cells for running digital
> cameras and have to say I'm far from impressed.

My experience with NiMH in digital cameras is similar. I have gone
back to using disposable alkaline cells in my DSLR.

Andy

[sisu1a]

> Paul, Have you been using one in your plane ?

Goodness no, I can't even afford anything that draws high power, let
alone one of these bad boys to juice it. I myself am going to wait for
prices to come down a little bit first, and until then just deal with
the extra few pounds of lead in my current brick. It'd sure be swell
though...

-Paul

[James Hamilton[_2_]]

At 22:55 04 December 2008, Andy wrote:
>On Dec 4, 3:21=A0pm, Martin Gregorie
> wrote:
>> Slightly hijacking this thread:
>>
>> Can anybody recommend a reliable manufacturer of NiMH batteries.
>>
>> I've tried a variety of makes of 2 - 2.4 Ah AA cells for running
digital
>> cameras and have to say I'm far from impressed.
>
>My experience with NiMH in digital cameras is similar. I have gone
>back to using disposable alkaline cells in my DSLR.
>
>Andy
>

Regarding NiMH batts for digital cameras, I have been involved in soaring
and photography for about 40 years. Two years ago I wanted a small but
capable digital camera and, after much research, decided to go with a
Canon Powershot S3 IS. But, this is not about the camera. I wanted long
lasting, reliable power for the camera so I did quite a bit of research on
the best batteries and charger to use. I found Maha Energy Corp in La
Verne, CA and bought one of their MH-204W chargers and 4 of their AA
2300mAH Powerex NiMH batteries. The (international) charger is a real key
in that it is able to charge the batteries to 99% of their rated power,
something most chargers cannot do. I have been extremely satisified with
the performance of these products over the past two years. Here is the
Maha website address:

http://www.mahaenergy.com/store/Index.asp

They now have Powerex batteries that are 2700mAH. Be sure to read the
details on what the MH-C204W charger can do...it's impressive.

James Hamilton
Reno, NV

[Mike[_8_]]

On Dec 4, 3:21*pm, Martin Gregorie
> wrote:
> Slightly hijacking this thread:
>
> Can anybody recommend a reliable manufacturer of NiMH batteries.
>
> I've tried a variety of makes of 2 - 2.4 Ah AA cells for running digital
> cameras and have to say I'm far from impressed.
>
> I have two good chargers (a Vencon which is mains driven and controlled
> by a PC and a Pro-Peak Prodigy II which runs off 12v and designed for
> field charging RC aircraft batteries). Both are peak chargers and can *
> record the mAh during charge and test discharge.
>
I never have had your problem Martin.

Abusing 7 cell 1700 and 1900 mAh, NiMH packs in electric sailplanes
(F5J), fast charging them at contests(up to 5 amps) and running them
at 50--60 amps for 40 seconds, they always lasted as well as the
NiCds, I used prior. I have a Triton charger, that records charge
rates and capacities. I would put my packs through several charge
discharge cycles once a week or so. One problem with NiMH batteries is
that they discharge faster than NiCds if left laying around. I did not
use blister pack batteries found in retail electronic shops though.



> I've yet to try a NiMH brand that comes near its rated capacity.
Most
> show an, ahem, spectacular drop in capacity during subsequent cycles.
>
> I've never had any of this nonsense from NiCd cells: they 'just
> work' (unless made by GP).
>
> Bottom line: unless I can find a brand of NiMH that does what it says on
> the tin there's no way I'm going to spend good money on using them to
> replace SLAs *or trust them to last out a decent xc flight.
>
> --
> martin@ * | Martin Gregorie
> gregorie. | Essex, UK
> org * * * |

[[email protected]]

Also check out the NiMH packs at
http://www.all-battery.com/rectangularnimh144v10000mahbatterypackforsolarpane lemergencelightcustomize.aspx.
This is a 14.4 volt 10 AH pack with a flat discharge rate. It weighs
about 2/3's of the typical 12 volt 7/8 AH sealed lead acid battery
used in most gliders. It's rated for 500 recharge cycles. You can also
but individual cells and make your own pack to what ever specs you
need.

Charlie

[Michael Huber]

I´ve been using a pack of LiFeP cells for 2 years now and won´t go back to
SLA. (20 x A123 in 4s/5p)
http://a123systems.textdriven.com/product/pdf/1/ANR26650M1_Datasheet_AUGUST_2008.pdf

Michael

"K M" > schrieb im Newsbeitrag
...
On Dec 4, 12:45 pm, sisu1a > wrote:

>
> 40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
> 12v 12 amp/hr lead brick but half the weight)
> 24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
> built in battery management system)
> Both series are claimed to be able to be charged on most standard lead
> acid chargers (set for AGM/GEL cells)
>
> -Paul

Paul, thanks for the links, I never knew these existed . If one can
actually get "Thousands of cycles" then these would be much more
affordable than the steep initial cost might sugest. Have you been
using one in your plane ?
Thanks

[princiar]

Hi,

You can also try this link for Li batteries
http://glider-equipment.nl/catalog/product_info.php?cPath=26_49&products_id=104
.. Maybe someone has already used tthem, and can give us advice.

Regars,
Pedro asw 27

On 4 dic, 20:45, sisu1a > wrote:
> *I dont mind using the sealed lead
>
> > acid batteries but the NIMH has many advantages . And yea, I know
> > price isnt one of them.
> > Thanks
>
> NIMH?!? If cost doesn't frighten you, then why not LiFePO4?http://www.valence.com/products/battery_modules/u-charge_xphttp://www.valence.com/sites/all/themes/valence/pdfs/U-Charge%20XP%20...http://www.valence.com/products/battery_modules/u-charge_rt
> (integrated battery maintenance version...)http://www.valence.com/sites/all/themes/valence/pdfs/U-Charge%20RT%20...
> Kick a$$ batteries with 1/4-20 threaded connections to boot...but
> certainly not cheap. Just talked to a nice lady there at Valence, and
> for reference:
>
> *40 amp/hr is $800 (U1-12XP, their battery which is the same size as a
> 12v 12 amp/hr lead brick but half the weight)
> *24 amp/hr is $600 ( U1-12RTL, same size/weight as above but with
> built in battery management system)
> Both series are claimed to be able to be charged on most standard lead
> acid chargers (set for AGM/GEL cells)
>
> -Paul

[Martin Gregorie[_4_]]

On Thu, 04 Dec 2008 23:50:59 +0000, Tim Newport-Peace wrote:

>
> Forget NiCD Martin. They will soon become unobtainable in Europe because
> EU directive 2006/66/EC Article 4 (and others) prohibits 'The placing on
> the market of portable batteries or accumulators, including those
> incorporated into appliances, that contain more than 0,002 % of cadmium
> by weight.
>
I know it! Pity, because they were reliable, bullet-proof batteries: I
used them to run the d/t timer on Free Flight models where reliability is
all: only 99% reliability = guaranteed model lost upwards.

NiMH has inferior cold weather performance to NiCd as well.

>
> Just remember that (in Europe) changing the primary electrical source is
> a Mod requiring a raft of EASA paperwork!
>
Interesting, so replacing SLA with the NiMH drop-ins advertised in S&G
will cause a paper blizzard.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Martin Gregorie[_4_]]

On Thu, 04 Dec 2008 17:18:17 -0800, Mike wrote:

> Abusing 7 cell 1700 and 1900 mAh, NiMH packs in electric sailplanes
> (F5J), fast charging them at contests(up to 5 amps) and running them at
> 50--60 amps for 40 seconds, they always lasted as well as the NiCds, I
> used prior. I have a Triton charger, that records charge rates and
> capacities. I would put my packs through several charge discharge
> cycles once a week or so. One problem with NiMH batteries is that they
> discharge faster than NiCds if left laying around. I did not use blister
> pack batteries found in retail electronic shops though.
>
Care to mention a brand name?

The best results I've had were with Vansons. They also died after 10
cycles or so, but that could well have been due to a crappy Chinese
charger I unwisely bought from Maplin.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[pigro[_4_]]

On Thu, 4 Dec 2008 17:18:17 -0800 (PST), Mike >
wrote:

> One problem with NiMH batteries is
>that they discharge faster than NiCds if left laying around. I did not
>use blister pack batteries found in retail electronic shops though.

Not all of them. A few have fixed the auto-discharge problem.
In Europe, commercial names are:

Uniross Hybrio
Sanyo Eneloop
Sony Cycle Energy

Aldo Cernezzi

[Mike[_8_]]

On Dec 5, 8:05*am, Martin Gregorie
> wrote:
> On Thu, 04 Dec 2008 17:18:17 -0800, Mike wrote:
> > Abusing 7 cell 1700 and 1900 mAh, NiMH packs in electric sailplanes
> > (F5J), fast charging them at contests(up to 5 amps) and running them at
> > 50--60 amps for 40 seconds, they always lasted as well as the NiCds, I
> > used prior. I have a Triton charger, that records charge rates and
> > capacities. *I would put my packs through several charge discharge
> > cycles once a week or so. One problem with NiMH batteries is that they
> > discharge faster than NiCds if left laying around. I did not use blister
> > pack batteries found in retail electronic shops though.
>
> Care to mention a brand name?

Martin,

I purchased my batteries here;

http://www.battlepack.com/NICAD-Battlepacks.asp

I do not see the batteries I purchased listed anymore. They were
"Zapped" 1700 and 1900 mAh 7cell packs. I think they were HR 1700 and
HR 1900 cells, but I do not recall the manufacture-it was five years
ago . The packs are in heatshrink, and I do not want to peel it off.
Any of the NiMH cells or packs currently sold by Battlepack would have
equal or better performance. They are higher capacity than when I was
buying them.

I have not flown RC for about four or five years, but after about two
year I recharged the packs and after a few charge/discharge cycles
they would charge up to the stated capacities.

Mike





>
> The best results I've had were with Vansons. They also died after 10
> cycles or so, but that could well have been due to a crappy Chinese
> charger I unwisely bought from Maplin.
>
> --
> martin@ * | Martin Gregorie
> gregorie. | Essex, UK
> org * * * |

[Free Flight 107]

I've used NiMH cells to make my glfider battery for over 5 years now.
I always charge them with an RC Hobby charger, they have given
excellent performance.

The reason I went to 11 cells is to get 14 volts so as to insure that
my aircraft radio did not drop off due to low voltage at the end of
the day (10.5 v is the cutoff for most radios).

The reason for not using Li chemestry cells is concern for possible
overheating, bursting of cells, and resultant "Very Energetic" fire
from the release of the Lithium inside the cells. The RC hobby has
burned down well over 100 houses, apartments, cars, trucks, model
planes and garages during the learning phases of using LiPoly
chemistry cells. They require extreme care in all phases of use to
avoid catching fire when overcharged, over-discharged, or compromising
the plastic cases. Currentlfy the biggest issue is "Balancing " them
so that one or more cells don't reach full charge prematurely. This
requires a tap on each cell led out to a balancing set of circuitry.
All this information, advice and hardware information is freely
available on the RC Forums.

The Li-ion and LiFe (A123) chemistries are also suseptable to these
events, but because of the steel cases, like NiCad & NiMh, will resist
abuse better than LiPoly. In actual practice they still use
specialized charging and balancing circuits, and usually over-
discharging circuits, esp. in consumer devices such as Laptops and
Cameras.

IMHO the NiMH is the most reasonable replacement for the SLA
batteries, unless you really want to be on the cutting edge (Bleeding
Edge) of the Li technology.
I was also unaware that many others had equiped their gliders with
NiMh batteries and and had uniformly good results with their use.


BTW, I take issue with; "Both LiFePO4 series (of batteries) are
claimed to be able to be charged on most standard lead
acid chargers (set for AGM/GEL cells)", unless a complete set of
charging and balancing circuity is included in the package. And at the
prices quoted, they really should be!!

Happy thermals,

Wayne

[Martyn Johnson]

At 19:11 04 December 2008, K M wrote:
I had similar thoughts some months ago. Being the owner of a DG glider, I
asked them for advice on NiMH & lithium based systems. The answers were:

"We several times have discussed this topic.

No doubt about that you can store more electric power in the same
compartment with the same weight. But you will need a special charger and
we have to make a "Technical Note" after having tested all technical
questions with this new power system (Temperature, Danger of Fire etc.)

On the other hand the battery of a self launcher always is big enough. And
we are supplying solar cells. With this eqipment you never will have any
electric power problems.

Often we do not have any problems with the weight because the batteries
are used as a counter weight for the correct C/G.

This all is the reason why we have not made such an investigations."

and...

"You just cannot change the battery system by your own. That is a "Major
Change" and must be certified by the manufacturer.
........
When you have any additional instruments and like to have a second battery
for them - strictly separated from the main electric system - you can use
another battery-system on your own risk. Of course this system never may
supply more than 14,4 Volt.

My advice:
Don't change anything! It might be dangerous."


The British Gliding Association picked up this discussion and published
this in their newsletter:

"Glider Batteries. Several new types of battery (NiMH, Li-Po, Li-ion etc)
are now on the market, as suggested alternatives to Lead Acid (gel). There
are a number of safety risks associated with batteries and with replacing
lead acid batteries with
non-lead acid alternatives. More information is available at
http://atsipowermanagement.co.uk, http://dg-flugzeugbau.de/forum-dg0.html
(click on English language forum and follow link to non-lead acid
batteries) and http://www.caa.co.uk/docs/33/CAP562.pdf (note this is a
15Mb document). The BGA advises owners to understand fully the need to use
the correct charging system, whether installed in the glider or not, with
whatever battery type is used; different technology batteries should not
be mixed. In terms of certification, glider parts should be approved by
the type certificate holder or by modification and should either be
released or a standard part. Glider batteries are normally
considered to be standard parts. Owners should ensure that, where
batteries are replaced by alternatives, the installation, aircraft
charging system (if appropriate), weight, balance and use meets type
design approval."


So...there may be certification and insurance implictions.

Cheers

Martyn



>Dear List,
>It is time to replace one of the battery packs for my sailplane. I
>currently use packs consisting of 7 2.5V SLA batteries to make a 14V
>pack. This has worked very well for me in the past but the AH on these
>cells is somewhat limited. I would like to ad a transponder and
>possibly some type of collision avoidance device so I am looking to
>upgrade the power supply. I have seen Nickel Metal Hydrate batteries
>that come in 12V and 10 to 14 AH sized the same as the SLA batteries
>alot of the glider people are using. There is a company in the UK ,
>ATSI, who markets these NIMH batteries for aviation use. My question
>is does anyone on the list have any experience with these or any other
>12V NIMH batteries for glider use. I dont mind using the sealed lead
>acid batteries but the NIMH has many advantages . And yea, I know
>price isnt one of them.
>Thanks
>

[Martin Gregorie[_4_]]

On Fri, 05 Dec 2008 09:07:56 -0800, Mike wrote:

> I purchased my batteries here;
>
> http://www.battlepack.com/NICAD-Battlepacks.asp
>
I notice a lot of Sanyo single cells in their catalog. If those are
anything like their NiCds, they'll do me!


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Michael Huber]

"Free Flight 107" > wrote

> The reason for not using Li chemestry cells is concern for possible
> overheating, bursting of cells, and resultant "Very Energetic" fire
> from the release of the Lithium inside the cells.

> The Li-ion and LiFe (A123) chemistries are also suseptable to these
> events, but because of the steel cases, like NiCad & NiMh, will resist
> abuse better than LiPoly. In actual practice they still use
> specialized charging and balancing circuits, and usually over-
> discharging circuits, esp. in consumer devices such as Laptops and
> Cameras.

I have seen reports of burned LiPo and also some LiIo batteries and I would
not use them in my glider (apart from the LiPo in every PDA, Cellphone, MP3
Player, ....). But I have never heard of any A123 cells starting a fire, and
there are modelers who did some serious abuse testing.

> BTW, I take issue with; "Both LiFePO4 series (of batteries) are
> claimed to be able to be charged on most standard lead
> acid chargers (set for AGM/GEL cells)", unless a complete set of
> charging and balancing circuity is included in the package. And at the
> prices quoted, they really should be!!

I have balancing tabs on my LiFe packs and use both, a standard lead acid
charger and a microprocessor controled charger / balancer combination.
Either way the individual cells stay pretty closely balanced.

If you want to know how some people (mis-)treat their A123 packs google for
"zip charging A123" ...

Michael