Tobbee,
What are you doing?
Mounting the batteries inside the hottest(killer of all things electrical) part of the airplane?
Not to mention on the fire wall with out even so much as vibration insulation.

Another thing.. When you secure batteries? Secure the packs across the lengh of the pack, not width. You're placing Stress points on the battery conectors.

You've been warned.

-Mustang51