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Author Topic: Battery life of larger depthfinders  (Read 235 times)

Offline Mtmouse

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Re: Battery life of larger depthfinders
« Reply #7 on: December 09, 2018, 03:20:12 PM »
Thanks Don and Tim!

Tim, I think a while back you posted about a lithium battery manufacturer that you like.  Could you repost the link here for any you recommend?

Mike

I use Bioenno Power and FVP-Power batteries, both are serving me well. The FVP-Power batteries are newer to me, the good thing with them is; you can wire them in parallel. They make a 7Ah and a 17.5Ah battery. I saw a resent re-life test with the FVP-Power 17.5Ah battery on a Lowrance Elite7 Ti, I believe he averaged around 17 hours.

Right now the only supplier of the FVP-Power batteries in North America is Mariner Sails in Texas. FVP-Power is an Australian company.

Yakfisher

Re: Battery life of larger depthfinders
« Reply #7 on: December 09, 2018, 03:20:12 PM »
yakfishing

Offline The Red Rocket

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Re: Battery life of larger depthfinders
« Reply #6 on: December 06, 2018, 10:56:51 AM »
So I got to wondering why a battery rated at, say, 9 AH would only provide 6 AH in real life. A short Google search led me to this explanation of everything you ever wanted to know (or did NOT want to know ) about battery life.

https://www.allaboutcircuits.com/textbook/direct-current/chpt-11/battery-ratings/

In a nutshell, the manufacturers' ratings are obtained by observing the voltage drop when it is hooked up to something with a modest sustained amperage flow requirement for a relatively short period of time under perfect operating conditions (temperature, resistance, etc.). So despite what you may think (and I actually did think) 2 batteries from different manufacturers claiming the same amp/hour life will very likely not last the same length of time or otherwise have the same performance.

This article doesn't deal with the lithium vs lead/acid question but that would require another search and it's time for a nap.

Another conclusion you can come to is that a retired fisherman has a lot of spare time in the winter!


Offline The Red Rocket

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Re: Battery life of larger depthfinders
« Reply #5 on: December 06, 2018, 10:40:40 AM »
The 9 Ti draws about 1Ah. The thing you need to consider is lead acid over lithium. With a lead acid battery, you generally only have about 70%(on the high side) of usable Ah, before the power drops to the point it cuts out. So with your 9Ah lead acid, you will only have around 6Ah of usable power. With lithium batteries it's closer to 90%.

I like to use at least a 20Ah lithium battery with my 9" units. You may be able to get away with a 15Ah, depending on how long your trips are.

Lithium cost more than lead acid, but you get a lot more charge cycles(live longer) and you have more usable Ah.

Acknowledging that you are far better informed about this than I am, Tim, I found with my old Lowrance unit that when I tested it the math worked out pretty close to the observed performance but the test was only approximate. But that said, since a charge lasted about 4 days of fishing I rarely ran it right down without recharging it at home and it did fail after about 6 years (I think). As a guesstimate say about 100-125 days of fishing which means it would have been recharged close to 100 times. It was a cheap, $25 - 7 AH unit I got at Bass Pro.

Remember too that the lithium unit will cost in the $150 range.

Offline MikeM

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Re: Battery life of larger depthfinders
« Reply #4 on: December 06, 2018, 08:11:30 AM »
Thanks Don and Tim!

Tim, I think a while back you posted about a lithium battery manufacturer that you like.  Could you repost the link here for any you recommend?

Offline Mtmouse

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Re: Battery life of larger depthfinders
« Reply #3 on: December 06, 2018, 03:11:50 AM »
The 9 Ti draws about 1Ah. The thing you need to consider is lead acid over lithium. With a lead acid battery, you generally only have about 70%(on the high side) of usable Ah, before the power drops to the point it cuts out. So with your 9Ah lead acid, you will only have around 6Ah of usable power. With lithium batteries it's closer to 90%.

I like to use at least a 20Ah lithium battery with my 9" units. You may be able to get away with a 15Ah, depending on how long your trips are.

Lithium cost more than lead acid, but you get a lot more charge cycles(live longer) and you have more usable Ah.

Offline The Red Rocket

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Re: Battery life of larger depthfinders
« Reply #2 on: November 29, 2018, 05:48:38 PM »
I'm no expert on this Mike but, as I understand it, you can just do the math. A 7 AmpHour battery will operate a device that draws 1 amp for 7 hours. I got a new Humminbird Helix 5 Chirp GPS G2 fishfinder last spring and used it all summer, powered by a 12 A/H battery. The specs say that the current draw for my unit is 600 milliAmps, which is .6 Amps, so my battery should run my ff for 20 hours. However, the stated draw is for maximum backlighting which is the biggest drain on the battery. I turned my backlighting down to 5 (10 is max) and had no problem operating it for about 7-8 hours a day for 4 days on a camping/fishing trip. Also, I had no problem reading it. I don't know what the specified draw is on the bigger unit you're getting but since your screen is maybe 3x the size of mine the lighting draw at maximum backlighting will be considerably higher as well. If you're only using your unit on day trips your 7 A/H battery may be ok but you would probably find a higher rated battery more satisfactory. The fly in the ointment is that as the battery becomes more and more discharged it becomes equally less and less efficient (think of an old car battery) so the math is probably not completely reliable and your real-life operating time will likely be somewhat less than the math would indicate. Tim Percy is the Lowrance guru and seems to always be messing around with his PA and electronics so he'd certainly be a better authority than me.

Just another 2 cents worth from me, my 5" unit is just fine for split screen sonar (2D) & mapping use, which is what I have, but if you'll also have either DI or SI (or both) and you want to use all of the functions together on a triple or quadruple split screen I doubt that you would find the 5" screen big enough. Again, others know better and can chime in on this.

Anyhow, enjoy your new unit - I hope Santa doesn't get that bad boy stuck in the chimney!  :o
« Last Edit: November 29, 2018, 05:49:55 PM by The Red Rocket »

Offline MikeM

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Battery life of larger depthfinders
« Reply #1 on: November 29, 2018, 07:53:24 AM »
Hi,

Bit of a random question..

I have my eye on this

https://www.cabelas.ca/product/118264/lowrance-elite-9-ti-mediumhigh-sonargps-combo-with-nav

Im concerned about battery life of a 9 screen and hi power transducer as I usually use a 9Ah battery. Generally I think 5 or 7 screens are common for kayak fishing.

Any thoughts?


 

yakfishing