FishFinders and battery useage (any electrians here?)

2 different systems(on my kayak) and 2 radically different battery
lifespans.

--------------------------------------------------------------------

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)
--------------------------------------------------------------------------


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

----------------------------------------------------------------------------
--

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

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.

--------------------------------------------------------------------

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)
--------------------------------------------------------------------------


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

----------------------------------------------------------------------------
--

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

Thank you for the explanation!


"Fritz Nordengren" wrote in message
news:_AWqb.140754$Tr4.363844@attbi_s03...
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.

--------------------------------------------------------------------

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)

--------------------------------------------------------------------------


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


--------------------------------------------------------------------------
--
--

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

"Fritz Nordengren" wrote in message
news:_AWqb.140754$Tr4.363844@attbi_s03...
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.


Fritz,

I didn't check the numbers, but your explanation is dead on.

Bob

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

--------------------------------------------------------------------

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)

--------------------------------------------------------------------------


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


--------------------------------------------------------------------------
--
--

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