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://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 or
 both, but I always start and run on both. I think I did start it long
 ago on one battery. Invoice from Digikey says 46 lbs. shipping wt. for
 the two batteries.

 Perry Mick

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

 You can save some weight with Li ion, but the charging scheme that we use
 for lead acids is unacceptable for li Ions and they will catch fire.  And
 with a pack that big, it will be a big fire.  So you would have to isolate
 the battery pack and use a proper computer to charge it and regulate inflow
 and 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 and
 low weight.  But you have to be careful with those things!  ALWAYS use a
 controlling 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 as
 airworthy. They are highly regulated items for just transport on aircraft,
 let alone an integrated part of necessary systems. David makes very good
 points 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


LiIon batteries has better performance. BUT they need special charger and cannot be used as capacitor for alternator ripple damping.  You will have to add a dedicated high performance capacitor near alternator. Technology creates more problems than it solves. Good for big expensive "birds".

B.r.

Viktor