FishFinders and battery useage (any electrians here?)

Hey Shred©

You are mostly concerned with amps -- the amount of electricity used.

your old set up your fish finder used 300 milliamps (or .3 amps)

your battery has 7 amp hours , which means, it will put out 1 amp for 7
hours or 7 amps for one hour.

7 amp hours divided .3 amps = about 23 hours of use


your new system has 7.5 amp hours (more power) but the Garmin uses .8 amps.

75 divided .8 = 9 hours of use.

Temperature, resistance and other factors enter in here. I dont know
where in the county you are but if the temps are cooler than with your
old system, you might see a drop in battery life.

SHRED© wrote:
2 different systems(on my kayak) and 2 radically different battery
lifespans.

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My old set-up:

Battery....Cabela's....12vdc..7.0Ah

Eagle FishEasy 2
Current Drain...................300 ma (lights off)
Output Power...................1500 watts (peak to peak)
187.5 watts (RMS)
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New system:

Battery........."Power Source" .....12VDC......7.5Ah


Garmin 160
Power
Usage.........10 watts max
Nominal.....12VDC @ 0.8 Amps

Performance
Sonar Power Output...........400 watts RMS
3200 watts peak to peak

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Now here is the symptoms. With my old setup the battery would last a long
while. I would guess 40 hours.
In my new setup, the battery lasts about 6 hours.

Above are all the specs I could find.
Are there any electrically minded folks here that could explain the
difference?
Is my new battery defective?

Thanks