LiFePO4 batteries keep going so long that you'll rarely see a discharge below 12V.
They behave fine in parallel, charge and discharge.
They hold a charge for ages, so those who put their glider away for the winter could fly months later on the old charge.... Not that anybody ever forget to charge batteries!
There's no need to keep the panel off after preflight. No more waiting to turn the transponder on until hooking up the rope. For those with bluetooth devices, no more "it won't connect to the logger" while taking up slack.
Dare I say no more excuse to not have a transponder?
WARNING: These batteries cost more than a roll of cheap yellow electrical tape on Amazon.
Jim
(You Only Live Once department)