RE: Battery Pack Mounting Advice
You cannot be too careful when it comes to vibration isolation.
There is some 1/8" to 1/4" single sided with adhesive foam tape available that would work well if applied to the wood surfaces of the braces that are facing the battery. That would probably be sufficient isolation to protect the battery from vibration. Should. If you had to, you could relieve the battery facing side of the wooden braces a bit to use thicker single adhesive sided foam tape, which would add a bit more protection to your battery pack.
In the old days, when all battery charging was done at the C10 rate (1/10th of the battery's rated output capacity in mah), we could totally wrap our batteries in foam without worry. Those days have long since gone. Leaving one side of your battery exposed to the air, except for where the foam on the bracing touches the battery, is an excellent idea. The first time that I used a fast recharger in a Kaos with a fully wrapped battery pack, I discovered thermal runaway (the battery overheated) which failed to trip the M.E.N. Charger into low rate and which cooked my battery pack. Luckily, the house didn't catch fire. The batteries in this pack were of the Nicad variety. Just imagine what would have happened with some of the latest choices in battery types.
There is more to this battery thing than most folks would think. I'm glad you thought of it and posted your query here on RCU.
Ed Cregger