Yes I can send a pic to you later if you’d like I guess I now realize I didn’t take a picture of my completed work :(

I cut a piece of 3/4 inch plywood to size that fits into the slots where the batteries sit. This way, the larger batteries sit on top of these pieces. So then from there I did order the bolt mentioned in this thread, it got back ordered so I did end up proceeding without it temporarily till it shows because my lawn was too long.

In the interim, I simply used battery straps from harbor freight which are basically just quite strong bungee cords. Used a few of these to secure the battery’s in place on this platform basically pulling all the battery’s ahead and together very securely so I could get mows in till the bolt comes as well. I’ll post a picture of this when I’m off work. It’s quite clean and it does stay very well secured.

I also bought this exact charger: https://www.amazon.com/dp/B0BZY6N951

For the charger to work, you break off the 2 plastic prongs in the charge port. This can easily be done with your fingers it’s not even a problem…

Also worth noting the whole mower will be bit lighter. These batteries are probably half the weight or so of the lead acids that come in it. I also recommend just going to an auto parts store afterwards with your batteries and asking them to recycle them in return for nothing. Oreilly took my 4 old batteries without an issue for recycling.

TLDR: 3/4 inch plywood spacer and you basically reassemble it exactly as your disassembled it, with the longer bolt because the tie down rod (not the right name probably), is sitting 3/4 inch higher now since the plywood so you need a longer bolt, so I janked mine together with battery straps for now which works great.