AKR,
Yes, "Jerry", has a large batch of them -- But I believe his are very heavy duty!!
Dates for aircraft batts, use a aircraft logbook entry, and may not be on the battery..
Problem being, most of these are not deep cycle, and espically for light planes -- aren,t much different than auto starting batts !!
For RE -- I would suggest, only deep cycle and even Less Schwab tire, has a golf cart battery, brand new -- for about $70...
What you use, depends on how serious you are !!
I have a cabin, supplied only by solar and a small wind gen--- as the batteries , are the "heart" of the entire system -- I use nothing but , good heavy duty, deep cycle....
In the end, for a serious system,that is depended on, I feel the cost of the batteries, pays for itself...If it is just for a few hours of standby, used might be fine.... G,day -- Bill H....