I would suggest to increase your battery terminal thickness. At the marked spots you will gett the current of your 8P over the nickel strip, which will be too much.
You could extend the terminals and solder them to the nickel between the batteries, but it would have been better to solder before spotwelding, to avoid to heat up the cells.
See here, 1. battery soldered carefullly after welding, still OK after 4 Seasons.
2nd battery was soldered first and then spotwelded.
