My ASG29E uses two lead acid gel cell batteries each with 9AH capacity,
these sit on the parcel shelf beneath the fuel tank. These are supplemented
by the solar panels that deliver about 1A in bright sunshine.
My panel includes LX8000 with flarm, V3 vario, Filser ATR500 radio, LX nano
logger and Glider Guider PNA (similar to an Oudie), also occasional use of
a Dynon Artificial Horizon.
I guess if you don't have the solar panels or if you use a transponder then
capacity will start to become an issue unless you go to Li-ion.

Regards,
Roy