battery question - need more juice?

[Limits]

So I followed YakDout's suggestion on how to mount my new HDS-5.

So to summarize my new FF in 3 words or less .. "I LOVE IT".

Took it out for an exploratory trip with my buddy and fellow BWEdger Kevin (aka Silbaugh4liberty) this past Sunday. The guys were impressed with the quality of the image, and kept asking if it was streaming HD, Netflix or DirecTv.

Anyway, I loved it till my full charged battery died about 3 hours into the session. Got it home and found the voltage had dropped to 11.52 Volts.

According to the manual, it can use a power source from 10 to 18 volts so I'm not sure why it suddenly powered off. I didn't to take a chance on rebooting and ruining the battery so I fished 'visible structure' without it.


So my question - what size battery SHOULD I be using to power this thing? Would be advisable to up the voltage, the amps or both?

i'm currently using a 12 v, 5 amp battery. Any suggestions on how to get more usage for this electronically challenged angler?

Thanks.