What battery to use??

[Shootstraight]

So I have a 1652 G3, I currently have a Minnkota Edge 55 on it. I’m trying to figure out what size lithium battery to get. Minnkota site say 50 amps per hour and will only give for full speed. That just seems way out there. So what are you guys using for trolling motor batts on tin boats. Typically fish 6 to 8 hours then charge them.

 

[Ray Clark]

I have a Minn Kota Powerdrive 55#. I use a 100Ah LiFePO4 to run it.

I've seen a recommendation recently on one of the web sites that suggests a battery with capacity twice the maximum amperage draw. That would mean 110Ah for my motor. I'm confident the 100Ah battery is enough.

 

[MrGiggles]

A single 100ah minimum.

 

[Shootstraight]

Thanks guys, I was hoping a 50 would handle it. I ordered two 50’s, one for electronics and other for tm. Just talked to owner of store and he has 100’s in stock so sounds like I should just do that.

 

[Ray Clark]

Thanks guys, I was hoping a 50 would handle it. I ordered two 50’s, one for electronics and other for tm. Just talked to owner of store and he has 100’s in stock so sounds like I should just do that.

I run two batteries. One is a Group 24 AGM cranking battery for the motor. The other is the 100Ah LiFePO4 for the TM and all of the electronics/electricals (fish finders, bilge pump, and rarely used nav lights).

 

[airshot]

I have a 55# MK 12v trolling motor rated at 55 amps max draw at wot. Haven't gone the lithium route yet !! But I have two 105 ah sealed agm batteries that will last for 8 hrs normal trolling. There is a formula for converting the agm draw to a lithium draw that will show how much lithium battery you need. I am no electrician but the battery companies have told me at least a 100amp lithium so you are probably good with that.

 

[Still Afloat]

So I have a 1652 G3, I currently have a Minnkota Edge 55 on it. I’m trying to figure out what size lithium battery to get. Minnkota site say 50 amps per hour and will only give for full speed. That just seems way out there. So what are you guys using for trolling motor batts on tin boats. Typically fish 6 to 8 hours then charge them.

The MK Edge doesn’t have a digital speed control so it uses more current than necessary at any speed slower than 100%. Basically, a resistor is used to dump current which in turn reduces the voltage at the motor. So the slower you go the more power is converted to heat through this resistor. A digital speed control (ESP) basically chops the DC current. When running the motor slower the current pulses are just farther apart. In other words slower speed actually means lower current consumption too.

Why am I telling you this? It explains why the MK specs only state the full power consumption.

If you upgrade the trolling motor to a “digital” model you may not need a 100 Amp/hr battery.

 

[Shootstraight]

The MK Edge doesn’t have a digital speed control so it uses more current than necessary at any speed slower than 100%. Basically, a resistor is used to dump current which in turn reduces the voltage at the motor. So the slower you go the more power is converted to heat through this resistor. A digital speed control (ESP) basically chops the DC current. When running the motor slower the current pulses are just farther apart. In other words slower speed actually means lower current consumption too.

Why am I telling you this? It explains why the MK specs only state the full power consumption.

If you upgrade the trolling motor to a “digital” model you may not need a 100 Amp/hr battery.

Good information, thanks! So what model tm start with digital and are you suggesting that digital models use less battery?

 

[AlanT]

Minn Kota is recommending a minimum of 50ah because a 55# thrust trolling motor will draw approximately 50 amps at wot. If you draw more amps than a lithium battery can provide you risk damaging the battery. So it's not about how long you can run a a trolling motor, but the maximum amperage your TM uses at full speed. We all have new behaviors to learn when switching to lithium, including the max voltage when storing the batteries long-term.

 

[Gstevens]

Good Thread! I have a couple rigs running 12v Minn Kota Powerdrive or Rip Tide Powerdrive as well as a Terrova all with iPilot on Micro skiffs or a 14.5’ starcraft. I find the 50ah Lifepo4 batteries work better than the 24 or 27 series deep cycle lead batteries for longer duration having full power. I have been really happy with these batteries. One is a combination starter -deep cycle to start my Suzuki 20hp the other is 50ah deep cycle only used just to power TM and a Garmin Chartplotter- haven’t run one dry in a full day on a river or lake. Boats are small and light and I would consider the 100ah if I was fishing where I couldn’t charge overnight between fishing days.

 

[Still Afloat]

Good point. But, it depends on the battery so it’s important to read the specs. I have an older 60 Amp/hr LiFe battery that capable of 80 amp current draw. Not that it makes sense to use it with at that load.

 

[Still Afloat]

Good information, thanks! So what model tm start with digital and are you suggesting that digital models use less battery?

Without a doubt. Depending on how you use it you could 4X longer runtimes.

 

[Ray Clark]

For anybody looking to find out more about some of the budget LiFePO4 batteries out there, I'd suggest some YouTube time. Two channels that I like are ReeWray Outdoors and DIY Solar Power with Will Prowse.

The two channels seem to be no-nonsense and are easy to watch, meaning they are well-produced and presented. Neither of the two channels are boat-related, but they do review/test batteries one commonly sees on Amazon. Will Prowse actually cuts batteries apart looking at build quality. For example, he recently did an 18 month follow-up on Weize 100Ah batteries. He compared an older Weize unit to a new one and found that Weize had begun to cut corners in their battery build and he pulled his buy recommendation because of it.

 

[airshot]

Makes me wonder where they get the money to buy all these expensive batteries and then just tear them apart ?? Buying a half dozen batteries to tear apart and compare?? Someone has an agenda to spend that type of money!!

 

[Shootstraight]

Makes me wonder where they get the money to buy all these expensive batteries and then just tear them apart ?? Buying a half dozen batteries to tear apart and compare?? Someone has an agenda to spend that type of money!!

I would think they get the money from having content that is liked and subscribed to.

 

[Ray Clark]

Makes me wonder where they get the money to buy all these expensive batteries and then just tear them apart ?? Buying a half dozen batteries to tear apart and compare?? Someone has an agenda to spend that type of money!!

I would say that the agenda is the monetization of their YouTube channels based on expertise they've developed and are good at packaging up. Only a relative handful of creators make anything from it, and many of those are actively moving to other streams like Patreon because YouTube is squeezing their income streams.

There are sites that estimate how much money these guys get from their respective channels.

According to one site, Will Prowse, the guy who cuts up batteries, makes $1.43 for every 1000 views on his channel. The latest vid of him dissecting the Weize LiFePO4 got 167K views in just three weeks. Based on all of his content, his estimated YouTube earnings over the past 90 days is over $5500. Since he doesn't destroy a battery in every video, his production costs are not nearly that great. In addition, many of the creators have other money streams coming from advertising and directing clicks to affiliated merchandise sites.

Yup...it's a money making business. The truly successful ones offer content that is useful in real life beyond cute kitty videos. Makin' money in 'Merica. Imagine that. Whoulda thunk it?

 

[airshot]

Well this techno stuff is all news to this old boy !! Thanks for "enlightening" me !!

 

[bscuderi]

I have a Minn Kota Powerdrive 55#. I use a 100Ah LiFePO4 to run it.

I've seen a recommendation recently on one of the web sites that suggests a battery with capacity twice the maximum amperage draw. That would mean 110Ah for my motor. I'm confident the 100Ah battery is enough.

I also did the same 100 AH lifepo4 for my 55# terrova. I was out from 5 am til 5 pm the other day and there was still life in my battery running fish finders trolling motors occasional stereo. They are so light you could always get a second if it’s not enough lol

 

[CRS]

The best way to predict how much battery life you are using is to get a Digital clamp meter. The are very simple to use and show exactly how many amps are being drawn. Unless my motors are freaks, running 100% is not practical. As speed increases amp draw increases they are not on parallel curves. Every motor is different I suppose so doing a check will show you what is the best for your situation. I just set the motor at a speed and record the amps, increase and record the amps. From the readings you know exactly how much run time at the various speeds. Keep in mind motor speed is not boat speed, wind and current will change that. The reservoirs I fish is electric or rowing only, so my electric motor is is also my travelling motor. Top speed is important to me, but I have found running 100% is not worth it in terms of battery life.

 

[Still Afloat]

Good Thread! I have a couple rigs running 12v Minn Kota Powerdrive or Rip Tide Powerdrive as well as a Terrova all with iPilot on Micro skiffs or a 14.5’ starcraft. I find the 50ah Lifepo4 batteries work better than the 24 or 27 series deep cycle lead batteries for longer duration having full power. I have been really happy with these batteries. One is a combination starter -deep cycle to start my Suzuki 20hp the other is 50ah deep cycle only used just to power TM and a Garmin Chartplotter- haven’t run one dry in a full day on a river or lake. Boats are small and light and I would consider the 100ah if I was fishing where I couldn’t charge overnight between fishing days.

Keep in mind that a 50 Amp/Hr lithium battery has roughly the same usable capacity as an 80 Amp/Hr AGM lead acid deep cycle. My larger boat has two 110 Amp/Hr AGM’s in series. When they fail the replacements will be two 100 Amp/Hr lithiums. The boat will loose about 140 pounds and the trolling time should increase roughly 50%.