The batteries are sold through Signature Solar... and are are the EG4 and LifePower4.
Tried to put links in but it wouldn't allow it. So it's:
signature solar dot com and then look for the EG4 and LifePower4 batteries.
If you go to YouTube there are several videos. Will Prouse opens one up as well as conducts capacity testing. It's like the third video from the top if you find his channel. I just typed "prouse" and his channel was at the top.
Is this the one you were thinking it was and what do you think?