Pontoon Boat & Deck Boat Forum

Does anyone have experience on changing the trolling motor battery which isn't wired to charge, as well as the DeepCycle Start Battery for the boat with Lithium Batteries?

Is it worth the $200-$300 increased expense?

Price is coming down on them and they work well for RVs as you can use a 100 percent of the amps hours compared to 50 percent for lead acid, way lighter and you may be able to get the same amp hours in a smaller size

Go search you tube and you will learn a lot about Lithium batteries, Will Prowse is one guy who will show you everything from what is in it to how to build your own.

Search LIPO batteries and he will be one that comes up or just go here
https://www.youtube.com/watch?v=xBonGQe363g

I replaced two starting bats with one Li and both trolling motor bats with Li.
Took a total of about 140 pounds out of the boat.
Been six or eight months and zero issues.
The starter runs all electronics and It has never dropped below 95%

I just replaced my $500 odyssey deep cycle with a 12v 100ah enjoybot LiFePO4 battery $320. The odyssey only lasted two and half years. Very disappointed.

I already have several NOCO charger that can charge lithium batteries. You should do some research on charging in extreme temperature. Some batteries have high and low temperature sensors and even built-in heaters. Charging them in freezing temperatures can permanently damage them.

Most lithium batteries will not replace the starter battery. Lead is still your best choice for that purpose.

As was stated you don't want to charge Lipo4 below freezing. Some batteries have auto temp sensing and will not allow to charge if below freezing. Some do not have that feature. If you charge one below freezing it will ruin the cells. The 300 and sub do not have it. Weize is about the lowest price with the low temp cut off currently. Price between 320-360 if you can find one. But it is changing daily. Some have heating pads that will heat the battery when you plug it in to charge and when it reaches an acceptable temperature it will start to charge. As of today those start at $450 and up. Some at this price level also have bluetooth to show the battery power level. There is a whole new entry of LIpo4 batteries designed for trolling motors and marine environments with ip67 cases that can be submerged for a few seconds. Most 100ah 12v batteries will handle up to 55# thrust. larger thrust will need bigger capacity but most of those are also 24 or 36 volt trolling motors.

You will also need a lipo4 charger these typically charge at a specific voltage for lipo4 I believe that is 14.2-14.6 and are capable of going into proper absorption stage of charging. An improver charger will cut off when it hits the last phase of charging and you will end up with a battery that is less than 100% charge. This will ultimately lesson the life of the battery.

You don't want to put lipo4 battery in the same compartment as your lead starting battery as the gasing from the lead battery will rust your lithium battery
You will most likely need to charge it with an independent charger to keep it optimal charge. You can probably look at a battery isolator or dc to dc charger to put some current into the lithium battery but it's not as clear cut and you may end up shortening the life of the lithium battery. The battery isolator will allow the motor to charge the starter battery as primary and then send excess current to lithium battery. When the lithium battery turns off additional charge it should not then kill your stator. which apparently could happen if you stopped the dc circuit.

Don't try to use the lithium battery as a starting battery. Yes it might work but it's way more amp draw then then they are designed for.

There's all kinds of videos on lithium batteries on youtube.

Feel free to reach out to me and I'll share some brands that I've found in my many hours of research.

Is it worth it? Well that is the question. If getting more trolling hours out of the same size battery is important then the lipo4 of the same amp hours will put out more energy because you can draw a lipo4 battery down to near zero something you should not do with lead. IF the lipo4 makes it to 2000 or higher charge cycles compared to lead acid at 600 life cycles then yes it would be financially worth it. But that is a big IF. If you don't kill the battery with neglect or improper use. If you don't get unlucky and by a battery that fails either because it was super cheap or just unlucky. If it does fail is the company you bought it from is still around and a real warranty without the cost of shipping a hazardous product back to them. I'm doing it because I want to fish a whole day on 1 battery and hope that it lasts 2000 charge cycles or close to 6 plus years.

That's a lot of info to keep in mind.

Thanks for all the info.