# Lowrance Fishfinders and battery life



## BlackJeep

Just wondering if anyone has tried the new Lowrance fishfinder with down scan imaging and what effect that has on your battery life. I currently have an Eagle Cuda s/Map 350 (made my Lowrance) and I get probably 50+ hours out of my battery before needing to charge. It's an LCD display and I believe only uses a single freqency for the FF.

I called Lowrance to ask what the current draw was on their Mark 4 and Elite 4 DSI units. I'm told the Mark 4 (FF/GPS only, no DSI) draws 0.25A and the Elite 4 DSI draws 0.75A. The DSI's color display and the higher freqs x 2 use more power. 

There are plenty of battery life calculators online but after trying a few, I got numbers from 6.5 hours to 46.5 hours. That's hardly helpful, so wondering if anyone has used one long enough to know. 

I'm using a 7 amp hour 12V battery.

I'm also curious if the DSI unit has traditional FF display modes. I would assume so, but I have not seen anything but the DSI and chart modes on the websites I'm looking at.


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## oxbeast1210

Can't help with the battery but from my research it does not have traditional ff capabilities which steered me away from it .


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## bp_968

BlackJeep said:


> I called Lowrance to ask what the current draw was on their Mark 4 and Elite 4 DSI units. I'm told the Mark 4 (FF/GPS only, no DSI) draws 0.25A and the Elite 4 DSI draws 0.75A. The DSI's color display and the higher freqs x 2 use more power.
> 
> I'm using a 7 amp hour 12V battery.
> 
> I'm also curious if the DSI unit has traditional FF display modes. I would assume so, but I have not seen anything but the DSI and chart modes on the websites I'm looking at.


Ok I signed up to help you out here, I'll also IM you as well but wanted to post this so other people could make use of the information.

Traditionally you shouldn't expect more then roughly half the stated amp/hrs from a lead-acid battery, especially when your device is pulling over 20% of the batteries stated capacity (so a 7amp/hr battery would really sag under a 1.5amp+ load, typically). Now again, this is all extremely variable depending on the age and condition of the battery. 

Since your drawing .7amp or 700mah from a 7 amp battery you could theretically get 10 hours from that battery if you could draw it down to zero (you can't). In reality you can only draw it to 20-30% and really 50-60% is much much safer for the battery (did I mention I hate Pb batteries?). So you can expect 5 maybe 6 hours from that battery if its new and fully charged the day before your trip. If you let it set around for a month you will have a fair bit less run-time and if your battery has some age to it you will also have less run-time. I would plan on 4-5 hours of battery life. 

If your willing to destroy the battery you could probably get 7-9hr's a few times from it before it didn't hold a charge very well.

Personally, and this is why I took the time to post this, I would go with a LifePo4 lithium battery. Their a safe, non-explosive, lithium tech used in some cars, and in growing amounts in the RC industry. Another option is lithium polymer which is cheaper, and slightly more energy dense but I really don't suggest them to non-hobbyists (as in batteries as a hobby, I know, odd right?).

Anyway, you can find these LiFoPo4 batteries (sometimes called prismatic) in 12v (12.8V) configurations to replace SLA (lead-acid) batteries pretty reasonably priced now days. I can post links if anyone needs them. I found one with a quick google search for 125$ that was 12.8V and 20Ah. That would give you a solid 20 hours of run-time without any damage to the battery (you can run LiFoPo4 down to around 20% without a problem. Personally I'd stick with 30%, but 20% should be fine for thousands of cycles).

You *will* need a special battery charger but those can now be purchased from any of the major online RC hobby stores for as little as 30$ now and the same charger will also charge your Nicads, NiMH, Pb(lead-acid), Lithium Ion, and lithium polymer.

This LiFoPo4 battery weighs in at 6.6lbs. The 42$ 12v 20Ah SLA battery on the same website weighs in at 14lbs. It also has a lower total watt/hr at 240watt/hr VS the LiFo at 256wt/hr. The LiFo also has more usable power since it has a much flatter discharge curve (meaning you keep your needed 12v longer then a SLA will) and you can discharge it deeper, safely, giving you the ability to access more of that 256wt/hr.

Anyway, I hope this helps. I intend to pick up one of these units for my new Coosa and plan on using the LiFo battery setup (or a LiPo since I have so many laying around, though setting my new boat on fire would certainly upset me).

-Ben


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## bp_968

Nevermind about the IM to the OP, I can't do it yet I guess. Hopefully he checks this thread.


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## Wilbur

I have the Elite 5DSI with a 12volt, 7amp hr SLA battery. Ive run it 9 hours with no problems. My battery tester showed that it had half its juice left after that. I thought about using LiPo, because they are great for model airplanes and cars, but I went with SLA for kayaking for the simplicity and reliability. I got my battery and connectors from Hobbytown.


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## bp_968

Wilbur said:


> I have the Elite 5DSI with a 12volt, 7amp hr SLA battery. Ive run it 9 hours with no problems. My battery tester showed that it had half its juice left after that. I thought about using LiPo, because they are great for model airplanes and cars, but I went with SLA for kayaking for the simplicity and reliability. I got my battery and connectors from Hobbytown.


well my numbers were based off the 700mah draw of the Elite 4 color unit. I have no idea what the draw is but its obviously not .7ah or you wouldn't have gotten 9 hours out of it. I'd be interested in seeing this battery tester that lists capacity too btw. At the best they can guess based off the voltage and where in its discharge curve it should be at that voltage but thats a pretty wide guess, certainly not accurate enough to say its got half its juice left. Laptop batteries (and similar) are able to give a estimated capacity only because they track discharge with built in hardware.

I gave up trying to figure out how much juice was left in NiMH AA batteries ages ago. It would often say they were good to go when they really only had a very small surface charge and would empty out a few minutes into using them. I switched to the Sanyo Entaloops because they hold their charge and are really durable. Much more reliable for my flash units and worth the 10-20% premium.

I'd probably stick with a SLA too if a 3-4lb 7ah gel cell gave me 9 hours+. I was reading far less runtime then that from other people using the new color Elite 4 units. Usually I get nothing but trouble from SLA's. I don't use it enough so it discharges, or I over discharge it and it never recovers, etc. Their just a pain. I can leave the LiPo or LiFe batteries laying around charged or discharged for a year or two and then pick them up and use them like they were fresh out of the package.


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## KayakFishingNC

I had the same Eagle Cuda 350 and recently got the Lowrance Elite 4 DSI as well as use a 12v 7amh battery. I've run it at least 30 hrs before charging again but usually charge it after each use.


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## bp_968

KayakFishingNC said:


> I had the same Eagle Cuda 350 and recently got the Lowrance Elite 4 DSI as well as use a 12v 7amh battery. I've run it at least 30 hrs before charging again but usually charge it after each use.


Ok then, this isn't adding up at all. If your lucky enough to own one of these magical 7ah batteries that really have 28ah then your set (unless you fish for 30+ straight without sleep).

or, something isn't right in the numbers ive been going by if you really get 30hrs from a 7ah battery. Thats about a 160mah draw, not a 700mah draw like lowrance is saying. 

EDIT: I located the manual for this unit (http://www.lowrance.com/upload/Lowrance/Documents/Manuals/DSI_COMBO_OM_EN_988-10153-001.pdf)

The manual states: "Current drain at 13.5V (250mA)" Which would get us much much closer to the magical 30hr mark then 700mah. It would also make battery purchases much much easier (since 7ah SLA's are *cheap*).

Knowing now that it can handle 10-17v (also pulled from the manual) makes me really happy. It means I can swipe a 4cell helicopter battery from my RC collection (15v-ish, at 5000mah). At roughly 1 pound and 6"x2"x1.5" its perfect for spending some time on a Kayak. I also have 3 of these hardcase batteries would be excellent for rough duty. Here is a link since their so cheap (22$)

http://www.hobbyking.com/hobbyking/store/__15521__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack.html

How do you guys store your batteries on the Kayaks? I really don't want a LiPo below hatch (i want it where I can see it) but at the same time it will need boxed or something to reduce chances of a short (which is a big big problem with these batteries). Just as an example, I've used one of my 2ah 12.6v 3cell lipo's to start a car before. It really will put out that much juice.

Its small enough I think I could just about strap it to the back of the Lowrance.


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## KayakFishingNC

I've never looked at the numbers other than knowing 12v was good for the unit. Maybe I have one of those "magical" batteries? All I can tell you is that that's what I can get out of it, albeit during a span of three outings not straight! I can also get two days of about 8-10 hrs each off a 12V 5ah AGM battery, a Werker WKA12-5F2. 

I carry my battery in a Pelican 120 case with thru housing connections. Goes inside the hull.


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## Wilbur

BP- A sealed bag for the LiPos would be good. That would definitely be lighter than a 7ah brick that I have. The good thing about the SLAs is that they are "sealed," so I think it's ok to let them get wet. Most people put them in a pelican box with silicon sealed holes for the wires. I just siliconed the connectors on mine and put it in the hatch (no box). To answer your other question, my battery tester doesn't really measure battery life remaining. I guess it estimates based on voltage. Regardless, the 7 ah works fine.


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## reyesm275

Ok I am reviving this post. 

I have a Lowrance HDS7 and I am running the Lowrance structure scan with it. I have a battery that does not last more than 3 hours running both at the same time. Is it the battery or the wiring that is wrong. I have check the wiring and it all seems good to me. I have never gone more than 8 hours on a battery so these "magical" batteries are what I need. 
BP-968 Please help me out you seem to know a lot about batteries.


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