SuperVee 27 battery question

I'm new to RC boating and just got a used Supervee 27. I was wondering if the boat can run with the battery connected in parallel instead of in series to extend the run time by sacrificing performance. I know my Traxxas mini E-Revo brushless can be run both ways I just don't know if the low voltage supply (7.2VDC) to the ESC and Brushless motor of the Supervee will cause damage. Another question.. I have 2 5000mAh batteries but one almost gone, can I use both and will the ESC and motor get damage of one battery drops out during run?
Thanks,

I just picked up a used SV27 too and I removed the series connectors and added a parallel adaptor. I plan to run two 4000mAh 4s packs as 14.4V setup. The boat had a lipo saver already installed so I need not worry about lvc. I anticipate long runtimes and my lipo packs weigh less than the two NiMh packs previously used. I just got last week and have yet to maiden.

Attachment 97050

This is the way I set it up for 4s2p, 14.4v combined 8000mAh of capacity.
The Nano-tech packs with 75C rating is complete overkill but these were borrowed from my edf jets.