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charging system

 
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fygdog(at)yahoo.com
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PostPosted: Sun Nov 27, 2011 2:43 pm    Post subject: charging system Reply with quote

hey guys'
this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
[quote][b]


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peteohms



Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

PostPosted: Sun Nov 27, 2011 2:51 pm    Post subject: charging system Reply with quote

Are you going to make up the battery yourself or use one made for aircraft? You can blow a couple hundred bucks in a heartbeat if you over charge one.
Pete
Sent from my iPad

On Nov 27, 2011, at 4:40 PM, steve feigley <fygdog(at)yahoo.com (fygdog(at)yahoo.com)> wrote:

[quote]hey guys'
this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
Quote:


[b]


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Pete
Leander, TX
Kitfox III, 912ul, Grove
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peteohms



Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

PostPosted: Sun Nov 27, 2011 3:04 pm    Post subject: charging system Reply with quote

U-Fly-It advertises one they say is more or less a drop in replacement for your regular battery and will charge off your existing alternator/ regulator.
Pete

On Nov 27, 2011, at 4:50 PM, Pete Christensen <pchristensen10(at)austin.rr.com (pchristensen10(at)austin.rr.com)> wrote:

[quote]Are you going to make up the battery yourself or use one made for aircraft? You can blow a couple hundred bucks in a heartbeat if you over charge one.
Pete
Sent from my iPad

On Nov 27, 2011, at 4:40 PM, steve feigley <[url=mailto:fygdog(at)yahoo.com]fygdog(at)yahoo.com (fygdog(at)yahoo.com)[/url]> wrote:

Quote:
hey guy s'
this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
Quote:




[b]


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Leander, TX
Kitfox III, 912ul, Grove
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pjeffers(at)talktalk.net
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PostPosted: Sun Nov 27, 2011 3:18 pm    Post subject: charging system Reply with quote

Weight saving is a good thing but be cautious of what reduced weight could do to your weight and balance. I know of at least one person who was going to fit one of these batteries and then discovered that he needed ballast to correct the c of g.

Pete


From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of Pete Christensen
Sent: 27 November 2011 22:51
To: rotaxengines-list(at)matronics.com
Subject: Re: RotaxEngines-List: charging system


Are you going to make up the battery yourself or use one made for aircraft? You can blow a couple hundred bucks in a heartbeat if you over charge one.



Pete



Sent from my iPad


On Nov 27, 2011, at 4:40 PM, steve feigley <fygdog(at)yahoo.com (fygdog(at)yahoo.com)> wrote:
[quote]
hey guys'

this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
Quote:

[b]


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Gilles.Thesee(at)ac-greno
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PostPosted: Sun Nov 27, 2011 4:01 pm    Post subject: charging system Reply with quote

steve feigley a écrit :
Quote:
hey guys'
this is for the electronics types listening . I'm thinking of trying a
lithium ion type battery for my 912s for the considerable weight
savings. the battery calls for a charge rate of no more than 18 amps
the 912 specs its elec. output at 20 amps. does this nessesarally mean
that it charges at that rate? also have any of you tried one of theese
batt, if so which brand from where?

*
*
Hi Steve,

What is the weight saving expected from the change ? The 912S starts and
runs very well with a 2,7 kg SBS8 Hawker lead-acid (VRLA), so is the
gain really worth the $ and trouble ?
Some info here http://contrails.free.fr/elec_bat_rg.php (mostly in
French, I'm afraid Wink, with lots of documentation at the bottom of the
page.

Best regards,
--
Gilles
http://contrails.free.fr


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craig(at)craigandjean.com
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PostPosted: Sun Nov 27, 2011 4:20 pm    Post subject: charging system Reply with quote

Note that the batteries offered by U-Fly-It are lithium iron phosphate (LiFePO4), not the more common lithium cobalt oxide batteries (LiCoO2). Other types of lithium ion batteries need to be carefully charged to prevent thermal run-away, rupture and possibly a fire. This is one reason why there are not drop-in lithium ion replacements for conventional battery sizes like AA, C, D, etc.

http://www.uflyit.com/new_page_57.htm

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

http://en.wikipedia.org/wiki/Lithium-ion_batteries#Safety_requirements

-- Craig

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of Pete Christensen
Sent: Sunday, November 27, 2011 3:03 PM
To: rotaxengines-list(at)matronics.com
Subject: Re: charging system

U-Fly-It advertises one they say is more or less a drop in replacement for your regular battery and will charge off your existing alternator/ regulator.



Pete
On Nov 27, 2011, at 4:50 PM, Pete Christensen <pchristensen10(at)austin.rr.com (pchristensen10(at)austin.rr.com)> wrote:
Quote:

Are you going to make up the battery yourself or use one made for aircraft? You can blow a couple hundred bucks in a heartbeat if you over charge one.



Pete

Sent from my iPad
On Nov 27, 2011, at 4:40 PM, steve feigley <fygdog(at)yahoo.com (fygdog(at)yahoo.com)> wrote:
Quote:

hey guy s'

this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
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Guy Buchanan



Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

PostPosted: Sun Nov 27, 2011 4:21 pm    Post subject: charging system Reply with quote

On 11/27/2011 2:40 PM, steve feigley wrote:
Quote:
this is for the electronics types listening . I'm thinking of trying a
lithium ion type battery for my 912s for the considerable weight
savings. the battery calls for a charge rate of no more than 18 amps
the 912 specs its elec. output at 20 amps. does this nessesarally mean
that it charges at that rate? also have any of you tried one of theese
batt, if so which brand from where?

I like the idea that if you have a particular type of charging failure
your battery catches fire. I understand it's a rather hot fire too.
Always exciting.

Guy Buchanan
Ramona, CA
Kitfox IV-1200 / 912-S / Warp 3cs / 500 hrs. and grounded
Now a glider pilot, too.


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Deceased K-IV 1200
A glider pilot too.
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rampil



Joined: 04 May 2007
Posts: 870

PostPosted: Sun Nov 27, 2011 6:21 pm    Post subject: Re: charging system Reply with quote

I also agree that the incentive to use an "exotic" battery for
a Rotax starter must be minimal.

The Rotax requires only a small lead-based battery, not much weight
saved compared with what's required for spinning up a TIO550!

The reference articles provided note that LiPo batteries don't overheat
(the old Halt & Catch Fire command) like LiCo, but do they just die
quietly when overcharged like LiCo?

If you're not expert enough to completely understand the engineering
considerations in switching, I'd leave to someone else to be first.

Ira
(EE in a former life)


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Ira N224XS
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BARRY CHECK 6



Joined: 15 Mar 2011
Posts: 738

PostPosted: Mon Nov 28, 2011 3:38 am    Post subject: charging system Reply with quote

Steve:

The "18 Amps" is not correct.
Here are the rules:
  1. Charger for NORMAL charge should be 10% of the rated AH ratting.
  2. So if the battery is 20 AH the charger should be MAX 2 Amps (20 * 0.10 = 2 Amps)
  3. The time to charge is AH divided by Charger Amperage AND that is from zero charge.
  4. So 20 / 2 = 10 Hours.
  5. Trickle Charge is 25% of Charger  2 * 0.25 = 0.5 Amps (500 mA)
  6. Get a GOOD charger that is designed for LITHIUM ION BATTERIES.
  7. Keep the battery COOL. Li batteries get VERY warm - HOT when charging.
That is all there is too it.. Other than don't over charge... Use a timer.
Barry

On Sun, Nov 27, 2011 at 5:40 PM, steve feigley <fygdog(at)yahoo.com (fygdog(at)yahoo.com)> wrote:
[quote] hey guys'
this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
Quote:


_blank">www.aeroelectric.com
.com" target="_blank">www.buildersbooks.com
="_blank">www.homebuilthelp.com
_blank">http://www.matronics.com/contribution
ist" target="_blank">http://www.matronics.com/Navigator?RotaxEngines-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution

[b]


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Float Flyr



Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

PostPosted: Mon Nov 28, 2011 9:42 am    Post subject: charging system Reply with quote

I would be careful there... A simple resistor could lower your charge rate inside the prescribed 18 A but the extreme current necessary to turn the starting motor could cause your LI Ion battery to go into thermal runaway a condition that could cause a fire.

Cloth covered planes are not good places to play with fire!

Noel

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of steve feigley
Sent: November 27, 2011 7:11 PM
To: rotaxengines-list(at)matronics.com
Subject: charging system


hey guys'

this is for the electronics types listening . I'm thinking of trying a lithium ion type battery for my 912s for the considerable weight savings. the battery calls for a charge rate of no more than 18 amps the 912 specs its elec. output at 20 amps. does this nessesarally mean that it charges at that rate? also have any of you tried one of theese batt, if so which brand from where?
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Aerocet 1100 Floats
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rampil



Joined: 04 May 2007
Posts: 870

PostPosted: Mon Nov 28, 2011 12:54 pm    Post subject: Re: charging system Reply with quote

And..
BTW, the 18 Amp limit on the Rotax 912 is by no means a hard limit,
like a "real" purpose designed battery charger.

18 A is simply and approximately the max current output capacity for
the stated voltage threshold of about 12 volts. You can pull more
current at a lower voltage but the $900 regulator may blow up.
An airplane's battery charging circuit is not microprocessor controlled like
the charger for an Apple laptop battery, airplanes do not either time the
charge or do they internally monitor the state of the state of the battery to
control shutdown of charging.
Overall, and not knowing the specifics of the specific vendor's product,
it does not sound like the best match to the Rotax.

What was the weight loss you calculated?


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BARRY CHECK 6



Joined: 15 Mar 2011
Posts: 738

PostPosted: Mon Nov 28, 2011 2:30 pm    Post subject: charging system Reply with quote

Ira:

Someone is feeding you a bucket of misnomers.
Alternator Regulators [APC, VCU, ACU, etc. or what ever you wish to call them ]  DO monitor the state of the battery.  If they did not you would constantly OVERCHARGE the battery and the life of the battery would be brought down to zero.
Even the Very OLD mechanical voltage regulators control the charge into the battery.
They DO NOT monitor the internal resistance of the battery.  Though some battery test units do calculate the value.


The ACU applies voltage to the FIELD of the alternator which turns the alternator ON  this usually takes place around 12.5 to 13.5 VDC.  The FIELD voltage is removed when the voltage across the battery reads 14.2 to 14.5 VDC.  Then the alternator is turned OFF.


The AMPERAGE of the alternator is a factor of wire size, diodes and slip rings.  The higher the amperage usually the bigger and heavier the alternator.  Of course there are differences between manufactures.  Advertising and sales spume not withholding.


IF the current draw was to exceed the rated amperage of the alternator say 18 Amps...  The fuse would pop.  If not - Someone did a poor job of design or install.  In most aircraft there are two fuses.. Alternator FIELD and Alternator OUTPUT.


If the voltage was to drop below 12 V as you stated the ACU would be OFF LINE - Something is Broke - And you would be drawing from the battery.
Barry


On Mon, Nov 28, 2011 at 3:54 PM, rampil <ira.rampil(at)gmail.com (ira.rampil(at)gmail.com)> wrote:
[quote] --> RotaxEngines-List message posted by: "rampil" <ira.rampil(at)gmail.com (ira.rampil(at)gmail.com)>

And..
BTW, the 18 Amp limit on the Rotax 912 is by no means a hard limit,
like a "real" purpose designed battery charger.

18 A is simply and approximately the max current output capacity for
the stated voltage threshold of about 12 volts.  You can pull more
current at a lower voltage but the $900 regulator may blow up.


An airplane's battery charging circuit is not microprocessor controlled like
the charger for an Apple laptop battery, airplanes do not either time the
charge or do they internally monitor the state of the state of the battery to
control shutdown of charging.


Overall, and not knowing the specifics of the specific vendor's product,
it does not sound like the best match to the Rotax.

What was the weight loss you calculated?

--------
Ira N224XS




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=359569#359569







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et="_blank">www.homebuilthelp.com
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[b]


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Gilles.Thesee(at)ac-greno
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PostPosted: Mon Nov 28, 2011 2:47 pm    Post subject: charging system Reply with quote

FLYaDIVE a écrit :
Quote:
Someone is feeding you a bucket of misnomers.

Alternator Regulators [APC, VCU, ACU, etc. or what ever you wish to
call them ] DO monitor the state of the battery. If they did not you
would constantly OVERCHARGE the battery and the life of the battery
would be brought down to zero.
Even the Very OLD mechanical voltage regulators control the charge
into the battery.
They DO NOT monitor the internal resistance of the battery. Though
some battery test units do calculate the value.

The ACU applies voltage to the FIELD of the alternator which turns the
alternator ON this usually takes place around 12.5 to 13.5 VDC. The
FIELD voltage is removed when the voltage across the battery reads
14.2 to 14.5 VDC. Then the alternator is turned OFF.

The AMPERAGE of the alternator is a factor of wire size, diodes and
slip rings. The higher the amperage usually the bigger and heavier
the alternator. Of course there are differences between manufactures.
Advertising and sales spume not withholding.

IF the current draw was to exceed the rated amperage of the alternator
say 18 Amps... The fuse would pop. If not - Someone did a poor job
of design or install. In most aircraft there are two fuses...
Alternator FIELD and Alternator OUTPUT.
Barry,


The Rotax alternator is a permanent magnet device, so no field circuit.
Anytime it is rotating it generates *voltage*. Alternators are
inherently current limited, so you just can't draw too much current, as
the voltage drops when current gets higher.
With a Rotax alternator and voltage regulator, we found it was safer not
to draw more than about 12 amps permanently, otherwise the regulator may
overheat if no special cooling is provided.
Some info on the study we did at
http://contrails.free.fr/elec_ducati_en.php.
Please note that the regulator schematic is provided as is, some time
ago some readers advised they had a more accurate drawing.

Best regards,
--
Gilles
http://contrails.free.fr


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craig(at)craigandjean.com
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PostPosted: Mon Nov 28, 2011 2:55 pm    Post subject: charging system Reply with quote

At least for the Rotax 912/914 the alternator is a permanent magnet alternator. Although it has a regulator it has no field windings or brushes. The schematic of the Ducati regulator is attached.

-- Craig

From: owner-rotaxengines-list-server(at)matronics.com [mailto:owner-rotaxengines-list-server(at)matronics.com] On Behalf Of FLYaDIVE
Sent: Monday, November 28, 2011 2:27 PM
To: rotaxengines-list(at)matronics.com
Subject: Re: Re: charging system


Ira:


Someone is feeding you a bucket of misnomers.



Alternator Regulators [APC, VCU, ACU, etc. or what ever you wish to call them ] DO monitor the state of the battery. If they did not you would constantly OVERCHARGE the battery and the life of the battery would be brought down to zero.

Even the Very OLD mechanical voltage regulators control the charge into the battery.

They DO NOT monitor the internal resistance of the battery. Though some battery test units do calculate the value.



The ACU applies voltage to the FIELD of the alternator which turns the alternator ON this usually takes place around 12.5 to 13.5 VDC. The FIELD voltage is removed when the voltage across the battery reads 14.2 to 14.5 VDC. Then the alternator is turned OFF.



The AMPERAGE of the alternator is a factor of wire size, diodes and slip rings. The higher the amperage usually the bigger and heavier the alternator. Of course there are differences between manufactures. Advertising and sales spume not withholding.



IF the current draw was to exceed the rated amperage of the alternator say 18 Amps... The fuse would pop. If not - Someone did a poor job of design or install. In most aircraft there are two fuses... Alternator FIELD and Alternator OUTPUT.



If the voltage was to drop below 12 V as you stated the ACU would be OFF LINE - Something is Broke - And you would be drawing from the battery.



Barry










On Mon, Nov 28, 2011 at 3:54 PM, rampil <ira.rampil(at)gmail.com (ira.rampil(at)gmail.com)> wrote:
--> RotaxEngines-List message posted by: "rampil" <ira.rampil(at)gmail.com (ira.rampil(at)gmail.com)>

And..
BTW, the 18 Amp limit on the Rotax 912 is by no means a hard limit,
like a "real" purpose designed battery charger.

18 A is simply and approximately the max current output capacity for
the stated voltage threshold of about 12 volts. You can pull more
current at a lower voltage but the $900 regulator may blow up.
An airplane's battery charging circuit is not microprocessor controlled like
the charger for an Apple laptop battery, airplanes do not either time the
charge or do they internally monitor the state of the state of the battery to
control shutdown of charging.
Overall, and not knowing the specifics of the specific vendor's product,
it does not sound like the best match to the Rotax.

What was the weight loss you calculated?

--------
Ira N224XS


Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=359569#359569

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Ducati_Regulator_Schematic.pdf
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craig(at)craigandjean.com
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PostPosted: Mon Nov 28, 2011 3:01 pm    Post subject: charging system Reply with quote

Oh please don't confuse us with actual facts and direct observations. This
is the Internet where we thrive on speculation and rumors. Wink

-- Craig
Quote:
"The Rotax alternator is a permanent magnet device, so no field circuit.
Anytime it is rotating it generates *voltage*. Alternators are

inherently current limited, so you just can't draw too much current, as
the voltage drops when current gets higher.
With a Rotax alternator and voltage regulator, we found it was safer not
to draw more than about 12 amps permanently, otherwise the regulator may
overheat if no special cooling is provided.
Some info on the study we did at
http://contrails.free.fr/elec_ducati_en.php.
Please note that the regulator schematic is provided as is, some time
ago some readers advised they had a more accurate drawing.

Best regards,
--
Gilles
http://contrails.free.fr"

-- Craig


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Gilles.Thesee(at)ac-greno
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PostPosted: Mon Nov 28, 2011 3:10 pm    Post subject: charging system Reply with quote

Craig Payne a écrit :
Quote:


Oh please don't confuse us with actual facts and direct observations. This
is the Internet where we thrive on speculation and rumors. Wink

;-D


Best regards,
--
Gilles
http://contrails.free.fr


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rampil



Joined: 04 May 2007
Posts: 870

PostPosted: Mon Nov 28, 2011 4:06 pm    Post subject: Re: charging system Reply with quote

Thanks Gilles,

For $900 the Ducati just isn't that great a regulator!


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Ira N224XS
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peteohms



Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

PostPosted: Mon Nov 28, 2011 4:27 pm    Post subject: charging system Reply with quote

$900? It was more like $160. When I replaced mine a couple years ago.

Pete

Sent from my iPad

On Nov 28, 2011, at 6:06 PM, "rampil" <ira.rampil(at)gmail.com> wrote:

Quote:


Thanks Gilles,

For $900 the Ducati just isn't that great a regulator!

--------
Ira N224XS




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=359583#359583












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Pete
Leander, TX
Kitfox III, 912ul, Grove
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fygdog(at)yahoo.com
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PostPosted: Mon Nov 28, 2011 5:20 pm    Post subject: charging system Reply with quote

--- On Sun, 11/27/11, rampil <ira.rampil(at)gmail.com> wrote:
Quote:

From: rampil <ira.rampil(at)gmail.com>
Subject: Re: charging system
To: rotaxengines-list(at)matronics.com
Date: Sunday, November 27, 2011, 7:21 PM

--> RotaxEngines-List message posted by: "rampil" <ira.rampil(at)gmail.com (ira.rampil(at)gmail.com)>

I also agree that the incentive to use an "exotic" battery for
a Rotax starter must be minimal.

The Rotax requires only a small lead-based battery, not much weight
saved compared with what's required for spinning up a TIO550!

The reference articles provided note that LiPo batteries don't overheat
(the old Halt & Catch Fire command) like LiCo, but do they just die
quietly when overcharged like LiCo?

If you're not expert enough to completely understand the engineering
considerations in switching, I'd leave to someone else to be first.

Ira
(EE in a former life)

--------
Ira N224XS


Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=359512#359512http://www.matronics.com/contributi; -Matt Dralle, List Admin= --> http://www.matronics.com/Navigator?RotaxEngines-List[b]the battery I am considering is sold at shoraipower.com and is of the lithium iron type, the current battery I use is a lead acid type weighing 13.3 lbs. the shorai battery with the same amp/hr rating and comperable cranking amps wieghs approx. 3 lbs. this is considerable but with the unknowns maybe not worth the risk

[quote][b]


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