It appears from the install instructions you can supply up to six batteries so that means connections can be added for more than the standard two battereis. That would tell me that you could add a longer hose, probably a neoprene hose to reach the other battery.
The longer hose shouldn't be longer than a hose that would serve six batteries. If your batteries aren't further apart than the distance of the six batteries you should be ok. A call to Flow Rite could provide you with the answer I would think.
2013 Voltage 3800, 2012 Chevy 3500 HD
2010 Yamaha V Star 950
2009 Yamaha Raider
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