Trolling motor batteries - round two

[210 FSH]

I use a 12V 125Ah IONIC Blue battery as my crank battery for my 150hp Mercury. It has never failed to start in the 3 years that I've owned it. And, yes, I was worried that a LiFePO4 battery might not start at Lake Powell when it was 24 degrees, but no problem. I have a 12V 100Ah LiFePO4 battery in parallel with the cranking battery, which I use for my electronics, including Livescope Plus. I have a 24V 50Ah battery for my Garmin Force. But the most important piece of equipment on my boat is the Power Pole CHARGE battery management system. It will manage any voltage, any type of battery, Lithium or AGM, together or independently and you control the how the power is distributed by an app. I have gone one week without plugging in to AC and that was before I added the 12V 100Ah battery. The CHARGE can manage 500Ah total capacity and it can take power from any battery for emergency start of the big motor if you need it. It is incredibly reliable and the app tells you if any battery needs power. Yes, it's expensive, but it's worth every penny. Also, the IONIC batteries not only charge 5x faster than AGM, but they have an 11 year warranty. I don't know if that will be important but maybe it will. Tight lines!

Hopefully you will not need the warranty and you will get more than 11 years out of your batteries! I’m planning on at least 15 years. From everything I’ve read on LFP batteries if, especially cylindrical cells, if one keeps the depth of discharge limited to 80% 5000 cycles is a realistic goal and perhaps more than that. The long life is where these batteries become cheaper than lead acid batteries.

The cold weather discharge performance has come a long way on lithium batteries as well, it used to be that if a lithium start battery, like those found in dirt bikes, acted like they were too low on power when it was cold, one just needed to apply load to the battery for a few seconds then wait a minute and try again. If it didn’t work again, apply load again for a few seconds then wait 30 seconds, the next attempt the battery would behave normally. The matrix inside the battery just needed a little heat, I’ve seen that in person on the factory KTM bikes. It appears now though that’s not necessary. And those batteries used in the KTMs may have been lithium polymer . Most LFP batteries will function normally down to -4F.

The CHARGE system sounds like a very valuable tool! I take it that it will keep the start battery isolated when the engine is off ?

 

[Mildog]

I’m taking a plunge on life po4 for my new boat.
I bought a lower priced eco worthy about 3 years ago to power electronic like live scope etc. I used in my boat and ice fishing in mid 20 degree temps Tried it a few times to power 50lb thrust electric motor guide on my little duck boat in cold weather. Works great!! When looking for batteries for my new boat, I found LiTime batteries (formerly amp time) found videos testing them read reviews by users. I also See they sponsor one of the pro fishing tours and are used with great success by many boaters and off grid as well as Rv users.
Prices are very attractive 5 year warranty and expected 10 years service life??? Time will tell.
*****INTERESTING NOTE!!! It is not recommended to run an electric trolling motor with brushes at 8,9 or 10 power for any extended period of time?? They way lithiums operate vs lead acid it Can damage the motor!! I know many use them and apparently don’t have issues!!
Minnkota advises it on their website !!!
****But be aware!!
New brushless motors like the NEW Minnkota Quest, the ghosts etc are no problem and designed For lithium batteries!

 

[210 FSH]

From Minnkota’s web site.

https://minnkota-help.johnsonoutdoors.com/hc/en-us/articles/6477037780631-Lithium-Battery-Selection-and-Recommendations?_gl=1*8avaxa*_gcl_au*NTI3MDMwOTUuMTc0MDAwMDU5Mw..*_ga*MTE0NzcwODkyMi4xNzQwMDAwNTk0*_ga_GTWTGQ93QM*MTc0MDAwMDU5NC4xLjEuMTc0MDAwMDY1Mi4wLjAuMTI4MjAzNjYyMg..*_fplc*TFJtJTJCJTJGdGclMkZIZ1g0YTRCODFKblBweDJYOUdlV0pWbkJYSFFGVkU2dEd5MjFsN0psNHAyV1MlMkJDaTJhaWtTR3RoMGZMWURtYiUyQlo2U0l6R0ZGQlVyJTJGdWlLdmZZWkpmYnY5Y3lFU0xkSlpMWFZTMk9nYXJuanRzbHBsbjd2b3pnJTNEJTNE

The brush style Minnkota motors can be run at 85% or 8.5 prop speed without issue. I’ve run my RipTide Ulterra this way for a couple of years now without any problems.

 

[PFD]

I had three Battle Born Lithium batteries for my trolling motor and switched them out for, as Donald Trump would say, one big beautiful Dakota 36v lithium battery. I did it for weight savings and haven't noticed any performance difference in the Garmin Kraken trolling motor. I have noticed a difference in getting my bow up out of the water with the weight savings. I'm a firefighter and would caution about going with a cheap lithium battery for a boat. I'd stick with Dakota, Battle Born, or Lion Safari higher grade lithium batteries. We see so many lithium battery fires. I wouldn't want a fire on the lake/water.

 

[Dorado]

I had three Battle Born Lithium batteries for my trolling motor and switched them out for, as Donald Trump would say, one big beautiful Dakota 36v lithium battery. I did it for weight savings and haven't noticed any performance difference in the Garmin Kraken trolling motor. I have noticed a difference in getting my bow up out of the water with the weight savings. I'm a firefighter and would caution about going with a cheap lithium battery for a boat. I'd stick with Dakota, Battle Born, or Lion Safari higher grade lithium batteries. We see so many lithium battery fires. I wouldn't want a fire on the lake/water.

This a common misconception regarding batteries. People discuss Lithium batteries as if they are all the same…Lithium iron phosphate (Lip04) are totally different than the Lithium Ion batteries used in cars, laptops, phones etc. They are pretty much never involved in fires…

 

[Boomer 1950]

I use 2 Millertech 36 volt batteries in parallel and I can get 2 full days of trolling motor use and the bluetooth says I still have 93% charge. They give you a great price and a great warranty. I have a 21 ft Lund with a 36 volt Ultrex trolling motor. Realistically, by using 2 batteries in parallel I believe you can get close to a week of use without recharging. Great if you are camping out .

 

[Flipper]

I use 2 Millertech 36 volt batteries in parallel and I can get 2 full days of trolling motor use and the bluetooth says I still have 93% charge. They give you a great price and a great warranty. I have a 21 ft Lund with a 36 volt Ultrex trolling motor. Realistically, by using 2 batteries in parallel I believe you can get close to a week of use without recharging. Great if you are camping out .

What size are these 36 - volt batteries? My boat has space for 3 - 27 series batteries.

 

[newfydog]

*****INTERESTING NOTE!!! It is not recommended to run an electric trolling motor with brushes at 8,9 or 10 power for any extended period of time?? They way lithiums operate vs lead acid it Can damage the motor!! I know many use them and apparently don’t have issues!!
Minnkota advises it on their website !!!

Indeed, I have a small pontoon powered by a Minnkota 30 and lithium battery. I tried going into a strong wind with waves to get to a sheltered side of a lake and burned it out. Long row back with crappy little crap oars. I upgraded to a bigger motor and now stay away from the highest powers.

 

[PFD]

What size are these 36 - volt batteries? My boat has space for 3 - 27 series batteries.

I believe it’s the same as a 31 series.

 

[Boomer 1950]

The batteries are 13 inch long by 6 inch wide

 

[capt-capsaicin]

I have not used the Dakota Lithium batteries but I have used IONIC Blues LiFePO4 with great success using a Power Pole CHARGE. Most pros recommend one high capacity 36V Lithium over the three 12V batteries because it takes a lot longer to charge them. On my Ranger, I run a 12V 125Ah LiFePO4 cranking battery in parallel with a 100Ah LiFePO4 battery which is wired to support my Garmin electronics including Livescope Plus. That gives me 12V 225Ah capacity for cranking and electronics. I run 8 gauge marine wire from the Garmin black box to the 12V 100Ah to ensure no voltage drop and degradation of the Livescope image. I use a 24V 50Ah LiFePO4 battery to run my Garmin Force, which gives me 275Ah total capacity. The batteries are managed and balanced by the CHARGE whether on the water or by AC. The CHARGE can also add power to the 24V battery from the 12V bank, and vice versa, in the worst case scenario that you need power from the trolling motor battery for an emergency start. Either way, you can't go wrong with using the LiFePO4 batteries; they are game changers.

can you use the trolling motor all day with just the 50ah battery? I always thought the trolling motor was the biggest power hog not the fishfinders.

 

[PFD]

can you use the trolling motor all day with just the 50ah battery? I always thought the trolling motor was the biggest power hog not the fishfinders.

Yes, I'm not sure of the exact calculations, but a 36v 50ah is roughly equivalent to a 12v 150ah battery. I'm sure someone can give me the exact calculations

 

[Dorado]

Yes, I'm not sure of the exact calculations, but a 36v 50ah is roughly equivalent to a 12v 150ah battery. I'm sure someone can give me the exact calculations

I had the same thought. But the trolling motor battery is 24v…I run 2 100ah 12v for my 24v Quest Terrova. I can troll for Kokanee all day and still have 60%. Assuming this equivalent to a 24v 50ah battery, that should be fine, especially since he has onboard charging.

 

[David A Dexter]

To capt-capsaicin, yes, I can run my Garmin Force all day on a 50Ah 24V battery. But, even if I couldn't, the Power Pole Charge can redirect charge from my other batteries to it if I need it.

 

[Mildog]

I believe some errors in above calculations
2 12 volt 100ah in series equals 24 volts still 100 amp hours.

A 36 volt 50 Amp would be the same as 3 - 12 volt 50 AH batteries wired in SERIES and have 50 amp hours.

If you hook 2 12 volt 100ah in PARALELL you will
Get 12 volts 200 AMP HOURS

RIGGED IN SERIES voltage increases AH remains the same
Parallel same voltage AH is doubled
Must be same AH to Combine

Here is approx AMP Draw of electric motors at various speeds. Based on 100AH battery.

 

[Boomer 1950]

My Millertech 36 volt batteries are 60 A.H. each. 120 A.H. Total. Wired in Parallel

 

[PFD]

I believe some errors in above calculations
2 12 volt 100ah in series equals 24 volts still 100 amp hours.

A 36 volt 50 Amp would be the same as 3 - 12 volt 50 AH batteries wired in SERIES and have 50 amp hours.

If you hook 2 12 volt 100ah in PARALELL you will
Get 12 volts 200 AMP HOURS

RIGGED IN SERIES voltage increases AH remains the same
Parallel same voltage AH is doubled
Must be same AH to Combine

Here is approx AMP Draw of electric motors at various speeds. Based on 100AH battery.

View attachment 31546

Sounds right.
3 50 amp 12 volt in parallel is 12v 150 amp.
Those same 3 in series are 36v but only 50 amp

Through the transitive step in reverse one 36v 50 amp batter would be equivalent to 3 50 amp 12 volt batteries
This is in terms of useable power to help calculate how long a trolling motor will last.
Thanks

 

[210 FSH]

Ah is voo doo witch doctor stuff… it’s highly variable. Watts are a measurement of work being done, that’s why it’s referred to as True power in a power triangle.

In a series connection watt hours are additive, your typical 100 Ah lfp battery is 1230 watts hours or 1.23 KWh. So, if you put three of those in series you have 100 Ah but you now have 3.69KWh.

How many hours or days of usage you get out of a battery bank is HIGHLY dependent on conditions and trolling speed or, KWh consumed. And unless you have a smart shunt that actually measures Ah / KWh you don’t know how much power has been consumed, anything else is a guess. Using voltage does not work, especially with lfp batteries since their voltage stays high almost all the way to the end.

Typically lfp batteries of a given Ah size have about 2.5 the capacity of fla batteries. This due to the peukert effect in lead acid batteries, the higher the rate of draw the worse a Fla battery capacity, and the fact that you can only get roughly 46% of a Fla batteries Ah rating. As such, the KWh storage capacity of a Fla battery is 46% of a comparable size lfp battery.

In terms of weight per kWh lfp batteries are 1/5th weight of Fla batteries.

The new brushless trolling motors are 30% more efficient than the ones with brushes, or they get 30% more mileage per kWh consumed than a trolling motor with brushes.

 

[Mildog]

Good stuff!

 

[Jerry D]

My boat came with a 12 volt power drive trolling motor on the front. When I upgraded to 24 volt Terrova I purchased a 24 volt Dakota Lithium because there isn't much space for two 12 volt batteries up front. It works great except for one drawback. I misread the amp draw for 24 volt Terrova and it will pull more amperage than permitted on battery at max power. I don't usually run trolling motor on Max anyway, so it hasn't really been an issue. Other than that it's been a great battery. Lightweight, charges easily with 24 volt lithium charger that purchased with battery. I found a great deal this winter on another 24 volt lithium this winter but haven't tried it on the boat yet. It's a Timeusb 25.6 volt 50 ah. Only paid a couple of hundred for it online.
Timeusbpower.com