lithium battery questions

[Doublebluff]

OK- debating whether to go lithium for my 9 ft pontoon. life span, cost, weight, run time differences... I get all that. I have read many posts and web articles but I still have a few questions.

I have read this...

"Lithium Batteries maintain higher voltages for longer. Motors engineered to make the most of flooded lead acid batteries can be damaged by the higher power output. To prevent this damage when using Lithium batteries you should not run your motor at its highest speeds, staying at 85%/Speed 8.5 or lower."

How do people address this with smaller trolling motors? Is this really an issue? If it is, I think it is a deal breaker for me. I don't want to have to keep checking that I might be over 85%.

Second- I have read about a "battery management system" that is important for lithium batteries. Are they usually part of the battery or do you have to buy that as well.

I am leaning toward buying a new lead acid battery and maybe a new trolling motor with a PWM built in. But the lithium option remains interesting to me.

 

[Tallguy]

Most newer trolling motors can handle the lithium power just fine, you need to check what the story is with your specific motor. Lithium are more expensive, but last much longer, deplete more slowly while sitting, are half the weight, and provide more power from the same amp-hour rating battery so you can run the motor much longer.

BMS should be built in. I bought the lithium. Read the care and use directions.

 

[ifsteve]

Just don't turn your trolling motor to full power. They all have increments or notches for some indication of power level. Not like you need to keep checking it. Go Li and you'll never look back.

Check out Li Time!

 

[Brian in OR.]

How Could A Lithium Battery Damage a Trolling Motor?

Like all other trolling motor brands, we advise against using lithium batteries without Battery Management Systems (BMS). Lithium batteries can run at a higher voltage for longer durations (14-16V) than Lead-Acid batteries (13V). Trolling motors are designed to be used with batteries that output around 13V at most.

Using a higher voltage can put wear and tear on the motor and potentially damage some of the internal components and ruin your motor.

A BMS will protect your motor from excess voltage. Fortunately, many lithium batteries include this part.

 

[iveofione]

Tallguy summed it up. Imagine a trolling motor box with a warning on it stating: "Not Compatible With Lithium Batteries"
That would be the kiss of death for sales and represent a step back in time and technology. Part of the expense of the new batteries is that they do include a BMS right from the get-go so just insure that you purchase a quality unit to begin with.

Just an example, I had used 5ah AGM batteries for my Garmin Stryker for years and they worked fine and I had 4 of them so I always had plenty of backup power. And although they were relatively small and light they were not put in your pocket light at 3 1/2 pounds. It turns out that at 3 1/2 pounds they were about 6 times heavier than a comparable lithium unit that lasted longer and took up much less space.

100 years from now when there are 25 billion people on the planet and every flat spot has either a tract home or a condo on it, lithium will be in the history books like tungsten bulbs are now. Get out there and enjoy it now for the great leap ahead that it is.

 

[Doublebluff]

I work in a tech driven field... yet I am reluctant to change battery types on my pontoon boat. We are all slaves to our inconsistencies I guess.

 

[Bambooflyguy]

I just checked…..no LI warning on my 1981 Minn Kota 65 MX, so I too will stick with my deep cycle!

 

[krusty]

One thing to be aware of for lithium batteries (in any application) is that they can easily be irreparably damaged if charged in either hot or cold conditions. Between 41 F to 113 F is the generally accepted charging temperature range for consumer grade lithium ion batteries. They operate just fine (though output will be diminished) outside such conditions...it is the recharging in those environments that's the problem.

While some lithium chargers and batteries have temperature measuring capability and will protect the battery, this simply means that the charger will not send current to the battery until ambient and battery temperature are in a suitable temperature range. Obviously in most cases it's the lower temp limit that results in damage. Probably not much of a problem for coastal Washington, but certainly an issue in many inland areas of the PNW.

So...do your lithium battery charging where the temperature environment supports healthy recharging.....and not outside or in a cold or hot garage.

As for Minn Kota and lithium ion batteries...

https://minnkota.johnsonoutdoors.com/us/blog/lithium-trolling-motor-batteries-advantages-and-compatibility#:~:text=After%20hearing%20the%20advantages%20of,run%20on%20Lithium%2DIon%20batteries.

 

[onefish]

I have an old school motor guide 12V electric 36. I also have a dakota 100ah LiFePO4 battery with a built in BMS that is now on its 4th season. I run my motor and sounder off the same battery. When fully charged it sits at 13.65 V, when in use it quickly drops to 13.2Vish and stays at 13.2-13.0V from 95% SOC - 20 % SOC. I use my electric for moving from spot to spot and I only use it at one setting, FULL THROTTLE. I seldom charge the battery to 100% and try to keep it between 85%-20%. I use the multimeter to get a better gauge of SOC and charge accordingly. For me one of the very best things about this battery is it loves to live in a perpetual state of partial discharge (40-80%) whereas Lead acid batteries hate being kept in that state. This makes it very easy to use the battery for a trip or two and then just leave it in storage for a long time before charging and doing zero damage to the battery. In fact, the instructions encourage you NOT to store the battery at 100%. If you charge a lead acid battery this way, you permanently damage the battery as lead acid batteries are best kept at 100% SOC as much as possible. At this point my battery still performs exactly as it did when I first purchased it. I got my battery when they were new and very very expensive. Prices have come down quite a bit and at this point it is very hard to justify buying a lead acid battery IMO.

 

[_WW_]

I use a 50ah Power Queen for trolling - 11.5 pounds and built in BMS for more protection than you'll ever need..

https://www.amazon.com/Rechargeable-Lightweight-Replacement-Wireless-Electric/dp/B09BQRF4N7/ref=sr_1_3_pp?crid=43C7CZ76FHZH&dib=eyJ2IjoiMSJ9.J1LiOxdT5qCGkFTWSQBc1ApUz-gpe0Z7_7sWpckHyzgi_7tDW3mDsNsd7zdOyfUBexhLpktrLrATnYMKZaBTv3CWk30M0Lo5s8XHgP5GUzjUgRENwJ05DMUueWbTpFVxenEAvb2IJ_UV4MwhVcQ80d3lO7xr-eCk3X2rrR6H8wxP49u1I3dMifUhkydnwsjJ.xdsZxSbugJMHf-TqOAwN5bMWXMPp0y_zR1ejCKjaZ4U&dib_tag=se&keywords=powerqueen%2B50ah&qid=1708437144&sprefix=powerqueen%2B50ah%2Caps%2C173&sr=8-3&th=1

I am right now in the process of converting my R_Pod over to lithium with a pair of 100ah batteries and installed the new converter in the trailer over the weekend. I have also purchased 4 small heating pads at 20 watts each that will be switched and attached to the batteries for charging them and running them in sub-freezing conditions. Conditions I don't expect to encounter very often.

 

[BigSplashTom]

I purchased a 18Ah LiFePO4 Lithium Battery for my pontoon boat running my Garmin Tracker.
The extra Amp hour rating allows me to fish 4 days before charging.
More importantly LiFePO4 Lithium Batteries are supper stable and much safer than Lithium Batteries.

 

[Chadk]

As others have said, go LiFeP04 and never look back.

 

[Doublebluff]

Well, I bit the bullet and went lithium. I also bought the smallest Minn Kota that has a PWM built in... Maybe a little overpowered for my 9 foot pontoon! As my buddy says, we'll be able to ski behind it. Thanks for all the input.

 

[BigSplashTom]

Well, I bit the bullet and went lithium. I also bought the smallest Minn Kota that has a PWM built in... Maybe a little overpowered for my 9 foot pontoon! As my buddy says, we'll be able to ski behind it. Thanks for all the input.

If you get a chance plz post a pic of the motor mounted on your boat.
I have a 9ft CDC pontoon boat and have thought about it too.
Most of the time I just kick and leave the oars at home.
It would be nice to have a small electric motor on large lakes.
Thx

 

[MELinOre]

Most of the time I just kick and leave the oars at home.

If you go the electric trolling motor direction, take your oars. If you leave the oar blades in the water they will help keep your pontoon heading in a mostly straight line.

 

[_WW_]

If you go the electric trolling motor direction, take your oars. If you leave the oar blades in the water they will help keep your pontoon heading in a mostly straight line.

I wear my fins and steer with them.

 

[Doublebluff]

MELinOre and WW... I do both of those things with my minnkota! Oars going forward, fins going backwards. It is quite a propulsion menagerie. BigSplashTom: I looked but I don't have the best pic of the motor actually mounted on my pontoon. But, here are a couple pics of how things look. I got new pontoons a couple years ago, the green ones are new. The battery and motor are the ones I am replacing.

 

[BigSplashTom]

MELinOre and WW... I do both of those things with my minnkota! Oars going forward, fins going backwards. It is quite a propulsion menagerie. BigSplashTom: I looked but I don't have the best pic of the motor actually mounted on my pontoon. But, here are a couple pics of how things look. I got new pontoons a couple years ago, the green ones are new. The battery and motor are the ones I am replacing.

View attachment 105940

View attachment 105941

Thx for sharing those pics. Looks pretty cool.
I know on bigger water it's getting hard for this old guy to kick my way out and back.
Elec. motor seems like a viable solution.

 

[up2nogood]

Well, I bit the bullet and went lithium. I also bought the smallest Minn Kota that has a PWM built in... Maybe a little overpowered for my 9 foot pontoon! As my buddy says, we'll be able to ski behind it. Thanks for all the input.

I too last summer , the AGM wore out it’s welcome. 100 amp for my 10 footer. Plus a charger that handles the lithium.

Would never go back to any other battery.

 

[up2nogood]

I wear my fins and steer with them.

I have done that since day one with my first electric motor on my pontoon . The motor is set
straight , occasionally in the wind I’ll adjust the motor , so not to have to fight the direction I’m going .