Kayak Trolling Motor Battery

[drakesndrum]

Hello all! 

 

I am considering getting the Motorguide Xi3 kit from Kayakfishingsupplies.com for my SS127, and am wondering about batteries.  Obviously lithium seems to be the way to go, but they are also super expensive.  The kit recommends using a 100ah battery to the run the motor efficiently.  For any of of you guys running this motor, or any motor, what battery setups are you running?  I usually only fish 3-6hrs at a time, so was wondering if a 54ah battery would suffice, both for cost purposes, and to save space and weight in my kayak.  Thanks for any help!

 

Adam

[J Francho]

You should ask them.  What do they recommend?

[Darth-Baiter]

My friend got the 12v 100 amp battery.  He gets a good day easy.   Same troll motor I think. 
 

I know he saved a few hundred not buying a Dakota Lithium. 

[Bankc]

First off, are you launching near where you fish, or are you going to have to travel a ways.  The reason is, the faster you go, the more energy your kayak consumes.  And it's not linear.  At half speed, you're consuming probably less than 1/4 the amount of energy as you would at full speed.  So if you're making long runs, you'll need a lot more battery than you would if you just putted slowly around for 6 hours.  

 

Also, battery type matters.  You're not supposed to drain a lead acid battery below 50%.  With a lithium battery, you can use the full capacity of the battery without damaging it. So, a 54Ah lithium battery has about the same amount of usable power as a 100Ah lead acid battery.  Plus lithium batteries output more voltage and weight less, so you can often go the same speed at a lower setting on the trolling motor.  

 

Quick math.  The Xi3 draws 52 Amps at full power.  Add a fish finder to it, and you'll get 1 hour of full speed operation out of a 54Ah lithium battery, assuming it's new and fully charged (they do lose capacity over time).  That means you'll probably get about 3-4 hours of run time at half speed, and maybe 10 hours at low speed.  That's all just me guessing though.  Each setup will be different and there are a lot of variables that can effect those numbers.  

[drakesndrum]

I typically launch near where I fish and fish smallish bodies of water and ponds.  My main reason for wanting the motor is the spot-lock feature for fishing offshore points ...case in point yesterday I found several concentrations of fish in 18-19', but with the wind I couldn't hold, even on anchor to effectively fish.  I doubt I'll be doing many long runs on full power.

 

My graph is on a separate battery so that won't draw any power from the motor.  Thanks for the help!  All ears to whatever you guys are running.

[Hook2Jaw]

I'm running a 12v 100ah Dakota Lithium because I needed a battery then and there, but if I had a chance to wait I'd grab an Amped outdoors battery.  They've been in the game a while and they're reasonably priced in comparison to a lot of the brands.

[casts_by_fly]

I have an autopilot and run an 80ah battery. I have a meter to watch it.  Some lakes I have to run a ways (they are 2000 acres and up) and I’ll burn most of the battery fishing a full 8-10 hour day. I mostly transit at full speed but I keep an eye on the meter and towards the end of the day I might throttle back a little.  On the 500 acre and smaller lakes I don’t even worry and blow around at full speed any time I need to.  

[TcRoc]

In the same “boat” .. not sure what battery to go with should I pull the trigger .. which possible new job may effect that as would be on the road a lot . But anyways my situation is a 7 mile lake with a average with of a 1/4 mile to a 1/2 mile . The xi3 would be used to get to destinations where I would be in shallows not using motor for most of casting time just point to point .. I’m sure I’ll use the spot lot in areas as well but again will be mainly used to get to point to point. Fishing this lake I choose a ramp and fish that area within a mile or so . Would that change with xi3.. probably but not alot. 

[Bankc]

I do use a 100ah lead acid battery in my kayak, and even on big lakes where I'm making a run of a mile or more, each way, I'll still get 6-8 hours out of it (Minn Kota Endura C2 30 that pulls 30Ah at max).  I've never had it completely discharge.  Though I have dropped it below the 50% threshold several times.  I'm not too worried about damaging that battery.  My thoughts when I bought it were to get a cheap lead acid battery at the time (because I had already spent a bunch of money on my kayak that year), and in a few years, upgrade to a lithium battery.  I've been running it for 3 years now, and it's still going strong.  But I might upgrade it later this summer.  We'll see.  The size and weight of it bother me more than anything else.  I haven't decided on size yet.  But I wouldn't feel comfortable with a 54Ah.  I'm thinking at least 80Ah.  

 

Another thing I forgot to mention was to check the maximum current draw of any battery before you buy it.  It's not usually a concern with lead acid, but some lithium batteries won't be able to output a full 50 amps at once.  Usually the more Ah the battery has, the more it can output at once. 

[MN Fisher]

1 hour ago, Bankc said:

I do use a 100ah lead acid battery in my kayak, and even on big lakes where I'm making a run of a mile or more, each way, I'll still get 6-8 hours out of it (Minn Kota Endura C2 30 that pulls 30Ah at max).  I've never had it completely discharge.  Though I have dropped it below the 50% threshold several times.

I had a 75ah SLA in the canoe running all my electronics (2 cameras, 8" Galaxy Tablet, Striker 7cv) as well as the Endura C2-30. 4-5 hours of water time and it'd still read at 75% charge.

[drakesndrum]

Thanks for the replies!

[casts_by_fly]

8 hours ago, TcRoc said:

In the same “boat” .. not sure what battery to go with should I pull the trigger .. which possible new job may effect that as would be on the road a lot . But anyways my situation is a 7 mile lake with a average with of a 1/4 mile to a 1/2 mile . The xi3 would be used to get to destinations where I would be in shallows not using motor for most of casting time just point to point .. I’m sure I’ll use the spot lot in areas as well but again will be mainly used to get to point to point. Fishing this lake I choose a ramp and fish that area within a mile or so . Would that change with xi3.. probably but not alot. 

sounds like the Nock and isn’t terribly different to Hopatcong here in NJ in terms of distance. Hopatcong is about 6 miles long and roughly a half mile if you want to cross it at most any point but it was originally two lakes that combined when the bottom lake was dammed so it’s not just a single valley and there are a couple big coves to factor in. That’s the biggest one I fish and manage it on an 80 Ah for the motor. I launch in the back of a cove roughly in the middle of the lake and have to pick left or right for the day.  If I wanted to fish the full perimeter I think I could mostly do it but that would be a looong day of shore pounding and not stopping to work much of anything in detail. 

[flyfisher]

Lithium has dropped in price considerably since last year when I bought my batteries for my motor on my kayak.  I needed a 24v so i got 2 12v wired in series 30ah and paid right around 750 i think.  Same company and same batteries i can get for a little over $500.  Same company has a 12V 100ah for $700 now.

Weight is a huge consideration on a kayak which is why i sprung for the lithium.  Less weight requires the motor to not work as hard and extends life.
 

If you are wanting to know how long a motor will last, motors should have specs of amp draw.  Alkl you need is ah/amp draw and that will give you a good estimate of time at that amp draw.  

 

For me, I'd err on the side of a bigger battery, especially if you have to paddle it if it burns out.  

I have a Newport Vessels nk180s and with my 30ah i can go 2+ hours at full tilt which I never do.  You also have to consider that, at least for my motor, going down in thrust has a minimal impact to MPH but battery life is extended exponentially.  

Totally worth crunching a few numbers and being realistic with your use and needs.

 

[cyclops2]

WOT amps is critical if you go off in any direction and there is only the launch ramp to pull it out to the trailer. 1 mile into baby white caps  with a rocky shore line ?  

NOOA weather report BEFORE you go out.  I have ROWED a 16' X 50" aluminum into small whitecaps for a mile.  Found out my heart was not so good. 0

 

Do a calculation of worst case you may face. Then modify battery to what you can spend. Call a couple of trolling motor companies with distance& wind condition you want to make it back to the ramp.  I have beached boats on protected sandy or grass beaches & waited out the wind.

 

[Alex from GA]

For $220 there is a 50ah lithium @ Amazon.  I bought one several months ago and use it several times a week on my tin bass boat.  I usually fish a river with a pretty good current and haven't come close to running it down.  It weighs 12 lbs and is = or greater to a group 27 lead acid in run time and lasts 10 times as long.  I don't see why anyone would not go with one of those.

[padlin]

Just a guess, but I'd say most folks that pass on lithium either don't know about them or prefer to spend less.

[MN Fisher]

8 minutes ago, padlin said:

Just a guess, but I'd say most folks that pass on lithium either don't know about them or prefer to spend less.

Not a pass - just on hold...super-tight budget, so initial batteries in the F-9 (1x100ah for TM, 1x35ah for 'housekeeping') are going to be AGMs.

 

Unless you want to contribute?

[FryDog62]

I fished a 60AH lithium on a 45 lb thrust autopilot for 2 months this winter on a 500 acre lake. Probably averaged 4-6 hours each trip, longest maybe 7. Never ran out of juice, most times battery still had 50% left and re-charged in 6-8 hours after I was done and ready to go again the next day. I didn't run wide open regularly, but usually did at least one trip at speed 10 from one end of the lake to the other. Seemed to work fine. 

 

I did upgrade to a 100AH, not because of the way I fish above but because next year I plan to go farther distances in the salt. If I stayed only on the 500 acre lake for 6 hour trips, the 60 AH would be plenty. 

[drakesndrum]

Thanks FryDog, that's exactly what I was looking for.  I tend to carry too much gear anyway, so saving on weight and space is a big deal.  Thanks again!

[Fred from Canada]

Hi everyone.   Purchase a 80Ah LFP battery from amazon.  They have come down in price so that they are around 2x the price of lead acid.

I am an engineer so I was skeptical of the claims made about the LFP batteries so I ran several experiments.

80Ah LFP produced 1040 Watt hrs + Weighs 25lbs

I tested 2 group 31 marine 105 Ah deep cycle batteries to compare.

1 battery was 6 years old and the other 1 year old.  I take good care of them.

#1 - 6yr old 105 Ah Lead acid = 680 Wh 

#2 - 1yr old 105 Ah Lead Acid = 800 Wh.

 

If you wanted the same capacity from a LFP battery you could use a 60Ah.  The 80Ah has a better price point.

 

Fred

 

 

[Motoboss]

Just bought a lithium MillerTech 75ah for my OT Autopilot. I was convinced by the ah availability, price and weight,,,20lbs!