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://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 big fire.So you would have to isolatethe battery pack and use a proper
computer to charge it and regulate  inflowand outflow current and
analize each individual cell  etc..

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 some  U-tube videos of NiCad putting out very high levels of
power.  The  charging requirements are not finniky like Lithium.

Dan F

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

Ni Cads could not be hooked up to an aircraft  electrical 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.  NiCad is
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 problems with memory.

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

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

BBBP12-12F2     12V 12AH AGM .250

They are about $80 each at:
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-
3126_7-34467853.html

Paul Lamar

Have you seen the BrailleBattery.com site.  Lithium batteries for drop in use
with alternators. Motorsport and power sport apps.

Dale Davies