Paul Remde wrote:
Hi David,

I highly recommend 12V systems in gliders. You can save yourself a lot of
money and hassle by using 12V batteries.

The design of radios has changed a lot in recent years. Good radios don't
require 14V batteries. Low cost and old radios do prefer 14V power.

Good Soaring,

Paul Remde


Mike et. al.

I used to be a "14 volter", using the old Gates Cells and later Sealed
Lead Acid. My new ship has all modern electronics (LNav, GPSNav,
Becker), and I have absolutely no issues running 12 Volts. I've
primarily used the Powersonic PSH-12100 (12V, 12AH) with good success.
I can easily get in a full weekend of flying (8-10hrs) on a single
charge. With reasonable care (storing in a cool, dry environment,
recharging after flying), they seem to last about 3-4 seasons (probably
about 150-200 cycles with my flying schedule). If you look at the
discharge charts, there's not a huge difference in useful time at our
typical discharge rates (on average less than 1 amp draw) between the
12AH and 10AH models, but it's only a couple of bucks more to buy the
higher capacity battery.

None of which, I guess, answers your original question.... The largest
capacity Powersonic that fits your specs is the PS-1229, which is only
2.9AH and 2.2lbs. Sufficient as a "get home" backup if you turn off
the radio but not what you'd want to run for a whole day of flying.
Also, in this case, there is some need to consider voltage drop across
the long wire you will have running back to the tail. You can make up
a 14 Volt kit by attaching an additional 2V 6AH cell that they have,
though in general they recommend matching the load ratings more
closely.

P3