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starter battery - LiFePO4

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kdietric

Joined: 16 Jan 2012
Posts: 15

Posted: Thu Apr 26, 2012 5:50 am Post subject: starter battery - LiFePO4

I'm just back from the AERO in Friedrichshafen and besides the Rotax 912is, I was impressed by the new LiFePO4 starter batteries on offer; the weight of those new batteries are below 1kg and they should perform as well or better than the normal lead/GEL batteries which are 6-7kg!



Does anybody have actual live experience with those new batteries in their Europa?

Could be a good way to save some kilos;-)



http://www.shoraipower.com/

http://www.a123systems.com/

http://www.accu-24.de/de/LiFePO4-Akkus

http://shop.strato.de/epages/61333079.sf/de_DE/?ObjectPath=/Shops/61333079/Categories/motorradbatterie--



Thanks,

Klaus (OE-CKD)

juliosalazarc(at)YAHOO.CO
Guest

Posted: Thu Apr 26, 2012 6:37 am Post subject: starter battery - LiFePO4

Unsubscribe



 

Julio Salazar Cerda

NO TEMAS; SOLAMENTE TEN FE

San Lucas 8, 50



â€œOnly when the last tree has died, the last river has been poisoned, and the last fish has been caught will 

we realize we cannot eat money."



[quote]      

  De: Klaus Dietrich <klaus.dietrich(at)me.com>

 Para: Europa-List Digest Server <europa-list(at)matronics.com> 

 Enviado: Jueves, 26 de abril, 2012 8:47 A.M.

 Asunto: starter battery - LiFePO4

   

 

--> Europa-List message posted by: Klaus Dietrich <klaus.dietrich(at)me.com (klaus.dietrich(at)me.com)>



I'm just back from the AERO in Friedrichshafen and besides the Rotax 912is, I was impressed by the new LiFePO4 starter batteries on offer; the weight of those new batteries are below 1kg and they should perform as well or better than the normal lead/GEL batteries which are 6-7kg!



Does anybody have actual live experience with those new batteries in their Europa?

Could be a good way to save some kilos;-)



http://www.shoraipower.com/

http://www.a123systems.com/

http://www.accu-24.de/de/LiFePO4-Akkus

http://shop.strato.de/epages/61333079.sf/de_DE/?ObjectPath=/Shops/61333079/Categories/mo="http://www.matronics.com/Navigator?Europa-List" target="_blank">http:--> http://for             - List Contribution Web Site -http://www.matronic====================



 

 

 [b]

pjlevi(at)gmail.com
Guest

Posted: Thu Apr 26, 2012 9:47 am Post subject: starter battery - LiFePO4

Klaus,



I purchased a similar battery at the Microlight Fair at Popham in May 2011 (cost was GBP 200.00).  I, like you, thought it would be a great weight saver as it was just under 1 kg.

   



However, when I showed it to my engineer, Pete Jeffers, I was horrified when he did the arithmetic on the weight and balance schedule and told me that it reduced my Europa to a single-seat aircraft and there was absolutely no way it could be installed as a simple replacement for the existing battery.  So, I suggest you check the weight and balance before purchasing - and if you need one, then mine is available second-hand unused!

   



Incidentally I have a LiFePO4 (Lithium Ferrous- (or Iron-)  Phosphate) battery in my folding electric bicycle and they are excellent, lightweight and extremely powerful compared to the older Lithium Ion batteries, but they also have the advantage of being less likely to catch fire when transported in aircraft.  See the British Airways Dangerous Goods List at http://www.britishairways.com/cms/global/pdfs/Forbidden_Items_List.pdf .  You will see that Lithium Ion batteries are only permitted in Cabin Luggage, not in the hold, so that in the event of a fire they can be put out quickly by cabin crew and also they are only permitted up to 160 Wh which is not very much.

  



My LiFePO4 bike battery by comparison is 370 Wh and was permitted for carriage on BA flights between LHR and Cape Town (I took it with hand baggage in the cabin) as LiFePO4 batteries are not considered a fire risk like their Lithium Ion predecessors and can be carried without a power restriction.  However, for the Europa, I think you will find that the weight and balance unfortunately becomes prohibitive unless you alter the location of the battery.  I am sure Pete Jeffers will be happy to give you more technical advice than I can offer, but it would need to be cleared with Ian Rickard and the LAA as a new mod. 

   



Philip Levi.

  



G-BWWB Europa Monowheel Classic, Compton Abbas.



  

E-mail:  pjlevi(at)gmail.com (pjlevi(at)gmail.com)  

   







  



 



On 26 April 2012 14:47, Klaus Dietrich <klaus.dietrich(at)me.com (klaus.dietrich(at)me.com)> wrote:

[quote]   --> Europa-List message posted by: Klaus Dietrich <klaus.dietrich(at)me.com (klaus.dietrich(at)me.com)>

 

 I'm just back from the AERO in Friedrichshafen and besides the Rotax 912is, I was impressed by the new LiFePO4 starter batteries on offer; the weight of those new batteries are below 1kg and they should perform as well or better than the normal lead/GEL batteries which are 6-7kg!

    

 Does anybody have actual live experience with those new batteries in their Europa?

 Could be a good way to save some kilos;-)

 

 http://www.shoraipower.com/

 http://www.a123systems.com/

 http://www.accu-24.de/de/LiFePO4-Akkus

 http://shop.strato.de/epages/61333079.sf/de_DE/?ObjectPath=/Shops/61333079/Categories/motorradbatterie--

    

 Thanks,

 Klaus (OE-CKD)

 

 

 

 

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  target="_blank">http://www.matronics.com/Navigator?Europa-List

 ====================================

 http://forums.matronics.com

 ====================================

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ====================================

 

 

 

 [b]

frans(at)privatepilots.nl
Guest

Posted: Thu Apr 26, 2012 3:16 pm Post subject: starter battery - LiFePO4

On 04/26/2012 03:47 PM, Klaus Dietrich wrote:

 	  Quote: 	
		   I'm just back from the AERO in Friedrichshafen and besides the Rotax

 912is, I was impressed by the new LiFePO4 starter batteries on offer;


	


The main problem with these batteries is that they require a totally

different way of charging. A lead-acid battery can be connected in

parallel with the alternator, and the lead-acid battery will just take

enough current to get recharged, and stops automatically. It won't get

any simpeler than that.

A LiFePO4 needs an overvoltage to initiate charging, strategically

tapered off to stop charging, and each individual cell needs to be

carefully monitored and balanced. It takes a lot of complicated

electronics, something we tend to avoid in aircraft. (You might look on

some wiki's on this subject to see what is needed to recharge these

babies properly).

The implication of all this is that you can not just connect the battery

in parallel to the alternator. In real life this means that you need to

run the ship entirely off the alternator, and the battery is connected

to the bus, not parallel, but via its complicated charger. If the

alternator momentarily needs some support from the battery it won't be

able to get it. Sure you can switch over to battery power, but you can't

use the alternator and the battery at the same time. Also, if I remember

correctly, the cell voltage of a LiFePO4 is 3.2 Volts. So you need to

operate at 12.8, which is quite low, or at 16 Volts which is a tad too

high. Normal lead-acid batteries parallel to the alternator operate at

13.7 to 14.5 Volts, and this is, not coincidentally, the voltage your

avionics is designed for.

LiFePO4 might become an interesting alternative once aircraft rated

chargers are developed, and when avionics is adapted to operate on the

new voltages. This is just not the time to do it, unless you want to be

the guinea pig.



Just my 2 cents.



Frans

craigb(at)onthenet.com.au
Guest

Posted: Fri Apr 27, 2012 3:05 pm Post subject: starter battery - LiFePO4

Philip  

   

You mentioned the issues of weight and balance, for not using the LiFePo battery, assuming you had the battery in the rear  

As per most builds, was the option of another half kilo of ballast near the tail considered, if so and you opted not to proceed  

Could you explain why. Given the weight saving would still be about 6kg, it would seem worthwhile to pursue  

   

Craig                        

   

       [quote][b]

grahamsingleton(at)btinte
Guest

Posted: Sat Apr 28, 2012 12:29 am Post subject: starter battery - LiFePO4

Craig,

you're right. moving the battery forward would require roughly half it's weight in the tail to compensate.

You save the weight of the cables too.  You need to consider keeping the battery cool if it's in the engine bay though.

Graham

        From: craig <craigb(at)onthenet.com.au>

 To: europa-list(at)matronics.com 

 Sent: Saturday, 28 April 2012, 0:04

 Subject: RE: starter battery - LiFePO4

  

 

                 Philip

     

   You mentioned the issues of weight and balance, for not using the LiFePo battery, assuming you had the battery in the rear

   As per most builds, was the option of another half kilo of ballast near the tail considered, if so and you opted not to proceed

   Could you explain why. Given the weight saving would still be about 6kg, it would seem worthwhile to pursue

     

   Craig                      

     

   

       [quote]http://=======================


[b]

europapa

Joined: 30 Aug 2010
Posts: 63

Posted: Sat Apr 28, 2012 3:14 am Post subject: Re: starter battery - LiFePO4

Hi,



I bought this battery:



http://www.aeroakku.com/product_info.php/info/p503_AEROAKKU-LFP-12-5-5.html



The seller ( not the one in the link ) told me that they have tree ultra lights in their airclub with this battery installed and they work fine.

The specific electronic should be installed in the battery so they could be swiched with the lead batteries.



Juergen

davidjoyce(at)doctors.org
Guest

Posted: Sat Apr 28, 2012 3:50 am Post subject: starter battery - LiFePO4

Craig & Graham, Right from the start I planned to have my 

battery in the engine compartment, and it has worked very 

well. It sits on top of the passenger footwell with a one 

inch retaining wall around its bottom end and fixed with a 

nylon strap from the firewall over the top and down. that 

is a much simpler and lighter mounting than any I have 

seen in the rear. I have an Oddyssey 17 amp hr battery 

which has had more than enough welly to start the engine 

instantly even after a 3/12 break in the winter. I made no 

provision for cooling and it doesn't seem to have noticed.

            As to weight and balance I have a mono XS, 914 

and a Woodcomp SR 3000 W wobbly prop and a very well 

equipped panel (although much of this electronic rather 

than steam age!), so my plane might be expected to be nose 

heavy. I calculated what I thought was the optimum 

position for the Ready for Service C of G as what would 

allow any combination of pilot/s, fuel & luggage and came 

up with the figure of 59 ins or thereabouts (but the 

precise figure will depend on the base weight of the plane 

but I guess the optimum will be very close to this) To 

achieve that precise CoG position I found I needed a 

small, 3 lb block of lead bolted to the front of the tail 

bulkhead (accessed conveniently through the trim slots). I 

suspect I had saved most or all of 3lbs in longer cables 

and more elaborate mounting & fixing of a rear battery. My 

advice would be to assume this  is wha.t you will do with 

the battery and only shift it to the much more 

inconvenient rear position if your plane turns out to be 

unexpectedly tail heavy.

Regards, David Joyce, G-XSDJ



On Sat, 28 Apr 2012 09:28:37 +0100 (BST)

  GRAHAM SINGLETON <grahamsingleton(at)btinternet.com> wrote:

 	  Quote: 	
		   Craig,

 you're right. moving the battery forward would require 

roughly half it's weight in the tail to compensate.

 You save the weight of the cables too.  You need to 

consider keeping the battery cool if it's in the engine 

bay though.

 Graham

 

 

 ________________________________

 From: craig <craigb(at)onthenet.com.au>

 To: europa-list(at)matronics.com 

 Sent: Saturday, 28 April 2012, 0:04

 Subject: RE: starter battery - LiFePO4

 

 

 

 Philip

  

 You mentioned the issues of weight and balance, for not 

using

 the LiFePo battery, assuming you had the battery in the 

rear

 As per most builds, was the option of another half kilo 

of ballast

 near the tail considered, if so and you opted not to 

proceed

 Could you explain why. Given the weight saving would 

still be

 about 6kg, it would seem worthwhile to pursue

  

 Craig

pjlevi(at)gmail.com
Guest

Posted: Sat Apr 28, 2012 6:55 am Post subject: starter battery - LiFePO4

Craig



My battery is indeed in the rear.  The possibility of adding weight to the tail was considered, but the amount required was such that the net weight saving by changing the battery would not be all that significant.  It is a relatively light aircraft as Europas go with a 912 UL engine but with an Airmaster AP332 VP propeller and the nose near the forward CG limit.  I also understand that adding significant weight to the tail can increase the propensity to ground loop.

  



Philip.

G-BWWB Europa Monowheel Classic



  



  





 



On 28 April 2012 12:49, David Joyce <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)> wrote:

  [quote]--> Europa-List message posted by: "David Joyce" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)>

   

 

 Craig & Graham, Right from the start I planned to have my battery in the engine compartment, and it has worked very well. It sits on top of the passenger footwell with a one inch retaining wall around its bottom end and fixed with a nylon strap from the firewall over the top and down. that is a much simpler and lighter mounting than any I have seen in the rear. I have an Oddyssey 17 amp hr battery which has had more than enough welly to start the engine instantly even after a 3/12 break in the winter. I made no provision for cooling and it doesn't seem to have noticed.

              As to weight and balance I have a mono XS, 914 and a Woodcomp SR 3000 W wobbly prop and a very well equipped panel (although much of this electronic rather than steam age!), so my plane might be expected to be nose heavy. I calculated what I thought was the optimum position for the Ready for Service C of G as what would allow any combination of pilot/s, fuel & luggage and came up with the figure of 59 ins or thereabouts (but the precise figure will depend on the base weight of the plane but I guess the optimum will be very close to this) To achieve that precise CoG position I found I needed a small, 3 lb block of lead bolted to the front of the tail bulkhead (accessed conveniently through the trim slots). I suspect I had saved most or all of 3lbs in longer cables and more elaborate mounting & fixing of a rear battery. My advice would be to assume this  is wha.t you will do with the battery and only shift it to the much more inconvenient rear position if your plane turns out to be unexpectedly tail heavy.

   Regards, David Joyce, G-XSDJ

 

 On Sat, 28 Apr 2012 09:28:37 +0100 (BST)

  GRAHAM SINGLETON <grahamsingleton(at)btinternet.com (grahamsingleton(at)btinternet.com)> wrote:

  	  Quote: 	
		   Craig,

 you're right. moving the battery forward would require roughly half it's weight in the tail to compensate.

 You save the weight of the cables too.  You need to consider keeping the battery cool if it's in the engine bay though.

 Graham

 

 

 ________________________________

 From: craig <craigb(at)onthenet.com.au (craigb(at)onthenet.com.au)>

 To: europa-list(at)matronics.com (europa-list(at)matronics.com) Sent: Saturday, 28 April 2012, 0:04

 Subject: RE: starter battery - LiFePO4

 

 

 

 Philip

  

 You mentioned the issues of weight and balance, for not using

 the LiFePo battery, assuming you had the battery in the rear

 As per most builds, was the option of another half kilo of ballast

 near the tail considered, if so and you opted not to proceed

 Could you explain why. Given the weight saving would still be

 about 6kg, it would seem worthwhile to pursue

  

 Craig             

 	
 



 ====================================

  target="_blank">http://www.matronics.com/Navigator?Europa-List

 ====================================

 http://forums.matronics.com

 ====================================

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ====================================

 

 

 

 



[b]

jan_de_jong(at)casema.nl
Guest

Posted: Sat Apr 28, 2012 7:24 am Post subject: starter battery - LiFePO4

I believe that a 12 V LiFePO4 battery is quite safe if used with care.

It does not have a thermal runaway mode, but will burn, not explode, if 

mistreated to an internal temperature of about 800 ºC (well above the 

melting point of aluminium).

By the way, LiFePO4 is not for low temperatures; one example increases 

internal resistance (4 mOhm) below 10 ºC as follows: 20 mOhm at 0 ºC, 40 

mOhm at -10 ºC etc.



How I intend to use with care:



1. Charge with a CC/CV regime, just like a lead-acid battery.

CC: small alternator, charging current guaranteed less than 2C

CV: maximum charging voltage 14.5 V; less is ok but the maximum SOC will 

be less than 100%



2. Cell balancing is much slower and worse than with a lead-acid battery 

(because a fully charged cell largely stops passing current).

Mitigation:

- long stays at CV interrupted by shallow discharges - normal starter 

battery use actually

- apply an external shunt (3.70 V) across each cell to speed up 

balancing if/when needed

Monitor:

- all cell voltages must remain below 4.00 V; remedy: stop charging



3. Replace if ever discharged to below 20% SOC

Monitor:

- battery voltage must remain > 12.8 V; remedy: if needed carry on 

discharging, but do not recharge, replace



4. Have 2



I designed a "monitor & top equalizer" for attachment to a Shorai 

LiFePO4 battery. It has just two indications: 1. a cell has a shunt 

operating, 2. a cell has a shunt operating but even so its voltage 

exceeds 4.00 V.

According to the battery suppliers no equalizing or monitoring is needed 

- which may be right ofcourse. Neither of the indications may ever show. 

On the other hand - they do sell balancing chargers...



Attached a typical charge curve for a LiFePO4 cell (author unknown). See 

the current drop when a SOC of 100% is approached.



Jan de Jong

40138chargeprofile.jpg

Description:

Filesize:

42.82 KB

Viewed:

14554 Time(s)

dpark748(at)hotmail.co.uk
Guest

Posted: Sat Apr 28, 2012 7:56 am Post subject: starter battery - LiFePO4

Recently seen a thermal run away on a seneca where battery is in the nose. Glad i was not in the air with it.!!!!!!



Sent from my iPhone

On 28 Apr 2012, at 16:35, "Jan de Jong" <jan_de_jong(at)casema.nl> wrote:



 	  Quote: 	
		   

 I believe that a 12 V LiFePO4 battery is quite safe if used with care.

 It does not have a thermal runaway mode, but will burn, not explode, if mistreated to an internal temperature of about 800 ÂºC (well above the melting point of aluminium).

 By the way, LiFePO4 is not for low temperatures; one example increases internal resistance (4 mOhm) below 10 ÂºC as follows: 20 mOhm at 0 ÂºC, 40 mOhm at -10 ÂºC etc.

 

 How I intend to use with care:

 

 1. Charge with a CC/CV regime, just like a lead-acid battery.

 CC: small alternator, charging current guaranteed less than 2C

 CV: maximum charging voltage 14.5 V; less is ok but the maximum SOC will be less than 100%

 

 2. Cell balancing is much slower and worse than with a lead-acid battery (because a fully charged cell largely stops passing current).

 Mitigation:

 - long stays at CV interrupted by shallow discharges - normal starter battery use actually

 - apply an external shunt (3.70 V) across each cell to speed up balancing if/when needed

 Monitor:

 - all cell voltages must remain below 4.00 V; remedy: stop charging

 

 3. Replace if ever discharged to below 20% SOC

 Monitor:

 - battery voltage must remain > 12.8 V; remedy: if needed carry on discharging, but do not recharge, replace

 

 4. Have 2

 

 I designed a "monitor & top equalizer" for attachment to a Shorai LiFePO4 battery. It has just two indications: 1. a cell has a shunt operating, 2. a cell has a shunt operating but even so its voltage exceeds 4.00 V.

 According to the battery suppliers no equalizing or monitoring is needed - which may be right ofcourse. Neither of the indications may ever show. On the other hand - they do sell balancing chargers...

 

 Attached a typical charge curve for a LiFePO4 cell (author unknown). See the current drop when a SOC of 100% is approached.

 

 Jan de Jong

 

 

 

 

 

 <40138chargeprofile.jpg>

jan_de_jong(at)casema.nl
Guest

Posted: Sat Apr 28, 2012 8:44 am Post subject: starter battery - LiFePO4

Probably a LiMnO2 battery. Not safe indeed.



Jan de Jong



On 4/28/2012 5:52 PM, david park wrote:

 	  Quote: 	
		   



 Recently seen a thermal run away on a seneca where battery is in the nose. Glad i was not in the air with it.!!!!!!



 Sent from my iPhone

 On 28 Apr 2012, at 16:35, "Jan de Jong"<jan_de_jong(at)casema.nl>  wrote:



> I believe that a 12 V LiFePO4 battery is quite safe if used with care.

> It does not have a thermal runaway mode, but will burn, not explode, if mistreated to an internal temperature of about 800 ÂºC (well above the melting point of aluminium).

> By the way, LiFePO4 is not for low temperatures; one example increases internal resistance (4 mOhm) below 10 ÂºC as follows: 20 mOhm at 0 ÂºC, 40 mOhm at -10 ÂºC etc.

>

> How I intend to use with care:

>

> 1. Charge with a CC/CV regime, just like a lead-acid battery.

> CC: small alternator, charging current guaranteed less than 2C

> CV: maximum charging voltage 14.5 V; less is ok but the maximum SOC will be less than 100%

>

> 2. Cell balancing is much slower and worse than with a lead-acid battery (because a fully charged cell largely stops passing current).

> Mitigation:

> - long stays at CV interrupted by shallow discharges - normal starter battery use actually

> - apply an external shunt (3.70 V) across each cell to speed up balancing if/when needed

> Monitor:

> - all cell voltages must remain below 4.00 V; remedy: stop charging

>

> 3. Replace if ever discharged to below 20% SOC

> Monitor:

> - battery voltage must remain>  12.8 V; remedy: if needed carry on discharging, but do not recharge, replace

>

> 4. Have 2

>

> I designed a "monitor&  top equalizer" for attachment to a Shorai LiFePO4 battery. It has just two indications: 1. a cell has a shunt operating, 2. a cell has a shunt operating but even so its voltage exceeds 4.00 V.

> According to the battery suppliers no equalizing or monitoring is needed - which may be right ofcourse. Neither of the indications may ever show. On the other hand - they do sell balancing chargers...

>

> Attached a typical charge curve for a LiFePO4 cell (author unknown). See the current drop when a SOC of 100% is approached.

>

> Jan de Jong

>

> <40138chargeprofile.jpg>

grahamsingleton(at)btinte
Guest

Posted: Sat Apr 28, 2012 1:10 pm Post subject: starter battery - LiFePO4

David, 

I suspect you meant to say "unexpectedly nose heavy" ?

regards

Graham

        From: David Joyce <davidjoyce(at)doctors.org.uk>

 To: europa-list(at)matronics.com 

 Sent: Saturday, 28 April 2012, 12:49

 Subject: Re: Europa-List: starter battery - LiFePO4

  

 

--> Europa-List message posted by:  "David Joyce" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)>

Craig & Graham, Right from the start I planned to have my battery in the engine compartment, and it has worked very well. It sits on top of the passenger footwell with a one inch retaining wall around its bottom end and fixed with a nylon strap from the firewall over the top and down. that is a much simpler and lighter mounting than any I have seen in the rear. I have an Oddyssey 17 amp hr battery which has had more than enough welly to start the engine instantly even after a 3/12 break in the winter. I made no provision for cooling and it doesn't seem to have noticed.

           As to weight and balance I have a mono XS, 914 and a Woodcomp SR 3000 W wobbly prop and a very well equipped panel (although much of this electronic rather than steam age!), so my plane might be  expected to be nose heavy. I calculated what I thought was the optimum position for the Ready for Service C of G as what would allow any combination of pilot/s, fuel & luggage and came up with the figure of 59 ins or thereabouts (but the precise figure will depend on the base weight of the plane but I guess the optimum will be very close to this) To achieve that precise CoG position I found I needed a small, 3 lb block of lead bolted to the front of the tail bulkhead (accessed conveniently through the trim slots). I suspect I had saved most or all of 3lbs in longer cables and more elaborate mounting & fixing of a rear battery. My advice would be to assume this  is wha.t you will do with the battery and only shift it to the much more inconvenient rear position if your plane turns out to be unexpectedly tail heavy.

Regards, David Joyce, G-XSDJ



On Sat, 28 Apr 2012 09:28:37 +0100 (BST)

 GRAHAM SINGLETON <grahamsingleton(at)btinternet.com (grahamsingleton(at)btinternet.com)> wrote:

 	  Quote: 	
		   Craig,

 you're right. moving the battery forward would require roughly half it's weight in the tail to compensate.

 You save the weight of the cables too.  You need to consider keeping the battery cool if it's in the engine bay though.

 Graham

 

 

 ________________________________

 From: craig <craigb(at)onthenet.com.au (craigb(at)onthenet.com.au)>

 To: europa-list(at)matronics.com (europa-list(at)matronics.com) Sent: Saturday, 28 April 2012, 0:04

 Subject: RE: starter battery - LiFePO4

 

 

 

 Philip

  

 You mentioned the issues of weight and balance, for not  using

 the LiFePo battery, assuming you had the battery in the rear

 As per most builds, was the option of another half kilo of ballast

 near the tail considered, if so and you opted not to proceed

 Could you explain why. Given the weight saving would still be

 about 6kg, it would seem worthwhile to pursue

  

 Craig&nb="http://www.matronics.com/Navigator?Europa-List" ="http://forums.matronics.com" target="_blank">http://forums.matronics.                    &nbsptronics.com/contribution" target="_blank">http://www.matronics.com/contri================


	






 

 

   

 [quote][b]

davidjoyce(at)doctors.org
Guest

Posted: Sun Apr 29, 2012 1:56 am Post subject: starter battery - LiFePO4

Graham, No I meant it as writ! The original well thought 

out design was conceived around a 912 and a simple prop as 

I understand it. The significant extra weight of a 914 and 

a wobbly prop hanging on the front might be expected to 

make it relatively nose heavy. Ten pounds extra on the 

p[rop probably just about accounts for my 3 lb of lead. 

Regards, David

On Sat, 28 Apr 2012 22:08:31 +0100 (BST)

  GRAHAM SINGLETON <grahamsingleton(at)btinternet.com> wrote:

 	  Quote: 	
		   David, 

 I suspect you meant to say "unexpectedly nose heavy" ?

 regards

 Graham

 

 

 ________________________________

 From: David Joyce <davidjoyce(at)doctors.org.uk>

 To: europa-list(at)matronics.com 

 Sent: Saturday, 28 April 2012, 12:49

 Subject: Re: starter battery - LiFePO4

 

 

<davidjoyce(at)doctors.org.uk>

 

 

 Craig & Graham, Right from the start I planned to have 

my battery in the engine compartment, and it has worked 

very well. It sits on top of the passenger footwell with 

a one inch retaining wall around its bottom end and fixed 

with a nylon strap from the firewall over the top and 

down. that is a much simpler and lighter mounting than 

any I have seen in the rear. I have an Oddyssey 17 amp hr 

battery which has had more than enough welly to start the 

engine instantly even after a 3/12 break in the winter. I 

made no provision for cooling and it doesn't seem to have 

noticed.

            As to weight and balance I have a mono XS, 

914 and a Woodcomp SR 3000 W wobbly prop and a very well 

equipped panel (although much of this electronic rather 

than steam age!), so my plane might be expected to be 

nose heavy. I calculated what I thought was the optimum 

position for the Ready for Service C of G as what would 

allow any combination of pilot/s, fuel & luggage and came 

up with the figure of 59 ins or thereabouts (but the 

precise figure will depend on the base weight of the 

plane but I guess the optimum will be very close to this) 

To achieve that precise CoG position I found I needed a 

small, 3 lb block of lead bolted to the front of the tail 

bulkhead (accessed conveniently through the trim slots). 

I suspect I had saved most or all of 3lbs in longer 

cables and more elaborate mounting & fixing of a rear 

battery. My advice would be to assume this  is wha.t you 

will do with the battery and only shift it to the much 

more inconvenient

 rear position if your plane turns out to be unexpectedly 

tail heavy.

 Regards, David Joyce, G-XSDJ

 

 On Sat, 28 Apr 2012 09:28:37 +0100 (BST)

 GRAHAM SINGLETON <grahamsingleton(at)btinternet.com> wrote:

> Craig,

> you're right. moving the battery forward would require 

>roughly half it's weight in the tail to compensate.

> You save the weight of the cables too.  You need to 

>consider keeping the battery cool if it's in the engine 

>bay though.

> Graham

> 

> 

> ________________________________

> From: craig <craigb(at)onthenet.com.au>

> To: europa-list(at)matronics.com Sent: Saturday, 28 April 

>2012, 0:04

> Subject: RE: starter battery - LiFePO4

> 

> 

> 

> Philip

>  

> You mentioned the issues of weight and balance, for not 

>using

> the LiFePo battery, assuming you had the battery in the 

>rear

> As per most builds, was the option of another half kilo 

>of ballast

> near the tail considered, if so and you opted not to 

>proceed

> Could you explain why. Given the weight saving would 

>still be

> about 6kg, it would seem worthwhile to pursue

>  

> Craig    =========================

grahamsingleton(at)btinte
Guest

Posted: Sun Apr 29, 2012 7:46 am Post subject: starter battery - LiFePO4

Now I'm confused! (again)

I was referring to your last sentence,

If the plane is tail heavy the battery needs to be at the front, yes?

Graham



 "My advice would be to assume this  is what you will do with the battery and only shift it to the much more inconvenient

 	  Quote: 	
		   rear position if your plane turns out to be unexpectedly tail heavy.> Regards, David Joyce, G-XSDJ


	






        From: David Joyce <davidjoyce(at)doctors.org.uk>

 To: europa-list(at)matronics.com 

 Sent: Sunday, 29 April 2012, 10:52

 Subject: Re: starter battery - LiFePO4

  

 

--> Europa-List message posted by: "David Joyce" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)>



Graham, No I meant it as writ! The original well thought out design was conceived around a 912 and a  simple prop as I understand it. The significant extra weight of a 914 and a wobbly prop hanging on the front might be expected to make it relatively nose heavy. Ten pounds extra on the p[rop probably just about accounts for my 3 lb of lead. Regards, David





 

 

  



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