From: reganranch@aol.com (ReganRanch)
Newsgroups: rec.aviation.homebuilt
Subject: Aircraft Batteries
Date: 24 Feb 1997 15:53:37 GMT

Bruce A. Frank points out:

<I continue to wonder why sealed starved electrolite 
<lead acid batteries have not taken over ALL portable battery usuage; 
<higher current density and higher voltage per cell. Everything you do to 
<a nicad is abuse- charge, discharge or float. Starved electrolite lead 
<acids- don't vent, don't leak, recharge in any posistion, and develop no 
<memory. Even charging them in reverse only shortens their life- not 
<instantaneous death as nicads do. There is a reason the military selected

<Concord sealed to replace all their nicad packs- and lead acids cost much

<less.


These starved electrolyte (AKA Lead Calcium or Gas Recombinant but NOT Gel
Cell) are great batteries. You can mount them in any position, drill a
hole in them and they won't leak, they don't vent (unless radically
overcharged) and they have a significantly lower internal resistance than
wet batteries. I think they were originally developed for UPS computer
power supplies. Can't have acid in the office.

I use two 12V 17AH (28 volt system) that have a combined weight of 28
pounds to start a TIO 540. A 12V 24AH weighs 19 LBS and costs $85. They
are made by Matsushita for Panasonic as the LCR battery. The only drawback
is that you have to make your own high current terminations to the
rectangular "P" type post. The post is lead alloy and should be completely
surrounded by brass or copper to prevent melt down during extended
cranking. I have 2 years, 300 flight hours and lots of hot starts on my
Panasonics.

They are available from B & C Speciality 316 283 8000, Allied electronics
800 433 5700 and Digikey 800 344 4539.

Power Sonic is another brand avail. from ACS. I do not have any direct
experience with them or Concord but both seem to be more expensive.

Brent Regan