Use these in airplanes to save some weight?

We usually use two independently switchable batteries (at least I
do)so the self-protection low voltage feature may not be a problem.

http://eetweb.com/power-
****supplies/lithium_**batteries_****3411/<http://**
eetweb.com/power-

**supplies/**lithium_batteries_**3411/<http://eetweb.com/power-**supplies/lithium_batteries_**3411/

<http://eetweb.com/power-
**supplies/lithium_batteries_****3411/<http://eetweb.com/**


power-supplies/lithium_**batteries_3411/<http://eetweb.com/power-supplies/lithium_batteries_3411/

http://4xspower.com/products/

Perry Mick

That is the way Mike set up the RV4. Is 28 AmpHr (both batts.)
enough for starting?

Paul Lamar

I currently use two Panasonic sealed lead-acid batteries. Just ordered
replacements as the existing have been in place for many years. Digikey
part number P049-ND, 28 AH each. I can independently switch in
either orboth, but I always start and run on both. I think I did
start it longago on one battery. Invoice from Digikey says 46
lbs. shipping wt. forthe two batteries.

Perry Mick

I used a single 16 AH SLA for starting just fine. But with Li Ion
it woulddepend on the "C" rating of the cells;If you figure
about 100A forstarting with your 28 AH pack, the C rating of the
cells should be 4C orgreater. Otherwise you risk fire and very
quickly degrading the pack.

You can save some weight with Li ion, but the charging scheme
that we usefor lead acids is unacceptable for li Ions and they
   will catch fire.  Andwith a pack that big, it will be a bigfire.So youwould have to isolatethe battery pack and use a proper
 computer to charge it and regulate  inflowand outflow current and  analize each individual celletc..

Also, a 28 AH pack will cost over $200, sometimes WELL over that.

I put the equivalent of a 48 AH pack into my skate board.Great
range andlow weight.But you have to be careful with those
things!ALWAYS use acontrolling circuit board.

-- David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

I have a sense that these LiOn cells would be rejected by your
DAR asairworthy. They are highly regulated items for just
transport on aircraft,let alone an integrated part of necessary
systems. David makes very goodpoints about their different
characteristics.
Your results may vary.
C. Smith
Always had good results with NiCad batteries in RC cars.There
are someU-tube videos of NiCad putting out very high levels of
power.Thecharging requirements are not finniky like Lithium.
Dan F

   On an experimental, the DAR is not going to probably even knowwhat kind of battery you use, nor is it his responsibility.That
 inspection is more of a paperwork drill.  You may use Li Ion if youwant as well.

Ni Cads could not be hooked up to an aircraftelectrical system and
charged like an SLA either.The charging algorithm for NiCads and
Ni Metal Hyd is the most difficult of all.Li Ions are actually
easy in terms of the computer knowing the state of charge... state
of charge is directly related to voltage.They wont work in a 12V
   system mostly because you must limit the charging current.  NiCadis the same, but at least they wont catch fire if you dont do it right.
With NiCads, the charge state is not represented by the voltage.

The charging computer must use a complex algorithm that looks at how
current has changed with voltage (and preferably temperature) over
   time to figure out the charge state.  NiCad also has problemswith memory.

Li Ion are still much better energy/weight than NiCad too.

   But just use an SLA with your 12V system.  Even the Nissan Leafhas a 12V SLA that takes care of the 12V systems leaving the Ni
Cads for   go-power.  Nothing beats the price/current and ease ofuse of the Lead Acids..

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

These are the Sealed Lead Acid batteries that fit Mike's battery box.

BBBP12-12F212V 12AH AGM .250

They are about $80 each at:
http://www.batteriesplus.com/**t-
browseall.aspx<http://www.batteriesplus.com/t-browseall.aspx

Mike used 2 in parallel for starting.

Dave, please bring your hand held radio on the 10th. I have not
bought the xcom yet. I had to spend some of the money I was saving
to buy Robin an Asus Transformer tablet fo her birthday.
http://rerviews.cnet.com/**tablets/asus-eee-pad-**transformer/4505-
<http://rerviews.cnet.com/tablets/asus-eee-pad-transformer/4505- 3126_7-34467853.html

Paul Lamar

  Have you seen the BrailleBattery.com site.  Lithium batteries fordrop inusewith alternators. Motorsport and power sport apps.
Dale Davies
I dont think those batteries are meant to be plug and play.Nowhere
on their site did I see anything mentioned about charging scheme. But it does state that the full charge voltage is 13.2 volts...so
what happens when you put them in a 14V system?  Some claim to havea max current rating of 1800 amps on a 28 AHr battery... that would
be a 64C rating... I don't think so!!!!!  That battery also costs $2AMUs... all to save about 10 lbs..
I think they are meant to be put in the system and used for the race,
but then removed and charged externally.

--David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net


Hi Dave,

Yes they are expensive. Leading edge tech is always that way. Give it a couple
of years and the prices will come down. $1000 to save a bit of weight is
pricey. Depends on how badly a person wants to reduce the weight.

For the alternator compliant; click on the Lithium battery section, then pick
a battery. In the specs/data will be a note about alternator safe use. They
say they have patented tech built in.

Dale Davies