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Discussion Starter · #1 ·
I am considering adding a TM to my Maverick 17 HPX-V. After speaking with several very reputable installers, most suggest the 24v system which I agree is the safe way to go but to keep all batteries in console I would need to reduce the Reserve min to 80-90 [email protected] Amps for the battery sizes to work.
A 12v system would be the easiest install and I have not ruled that out as I could install one grp 29 battery and get 210 RC min’s
Here’s where I could use help.
Different conditions require different amounts of thrust so to provide a simple comparison, the 55# MK draws 50 amps at max which will burn through a RC 120 battery in one hour. If I go 24v, the MK 80# using 55 lbs of thrust uses 38.5 amps based on 56 max amp draw x 69% of max thrust. In other words, if my math is good, the 80# motor requires roughly 75% of the amps to achieve the same thrust as the 55# motor. I am using terrova numbers here.
When I read comments like “if you fish in wind and current then go 24v” doesn’t that simply translate to more thrust for longer?
It would be great if anyone with my skiff would respond and/or anyone who would set me straight on what I am missing in my analysis.
Thanks
 

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I've had both 12v and 24v systems in 16-18 ft skiffs. Analyze the numbers all you want but the bottom line is that a 24v system will go about twice as long between charges in typical use and will have extra thrust available if it's needed. OTOH, 95% of the time a trolling motor is operated at much less than maximum power and a 12v will do the job and run long enough for a full day of fishing. A 24v system will cost significantly more than a 12v system and will add close to 100 lbs in battery, motor and charger weight. Tradeoff: longer run-time, more emergency thrust vs. more cost and weight. If you've got the $$$, will adding the extra weight matter to you?
 

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Discussion Starter · #3 ·
I've had both 12v and 24v systems in 16-18 ft skiffs. Analyze the numbers all you want but the bottom line is that a 24v system will go about twice as long between charges in typical use and will have extra thrust available if it's needed. OTOH, 95% of the time a trolling motor is operated at much less than maximum power and a 12v will do the job and run long enough for a full day of fishing. A 24v system will cost significantly more than a 12v system and will add close to 100 lbs in battery, motor and charger weight. Tradeoff: longer run-time, more emergency thrust vs. more cost and weight. If you've got the $$$, will adding the extra weight matter to you?
I've had both 12v and 24v systems in 16-18 ft skiffs. Analyze the numbers all you want but the bottom line is that a 24v system will go about twice as long between charges in typical use and will have extra thrust available if it's needed. OTOH, 95% of the time a trolling motor is operated at much less than maximum power and a 12v will do the job and run long enough for a full day of fishing. A 24v system will cost significantly more than a 12v system and will add close to 100 lbs in battery, motor and charger weight. Tradeoff: longer run-time, more emergency thrust vs. more cost and weight. If you've got the $$$, will adding the extra weight matter to you?
Thanks for your response and yes,weight is a concern. What is hanging me up is the suggestion of going 24v and using small batteries like a pc 1200 compared to a 12v system with a group 29. Won’t I give up a lot of run-time? For the time being I am sticking to flood and agm’s Until I decide how much I will actually use the TM. Not ready to go lithium until I get more experience. Bottom line I would like to go 12v to keep the weight down, system install more simplified and keep the cost down to get started but I have had 2 dealers tell me I am wasting my money and I will be so much happier with the 24v. That’s the reason why I took the approach with the thrust to better understand the recommendation. Thanks again
 

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If the cost doesn't make much difference to you, then you will be happier with a 24 volt system. If you're more economy minded, the 12 volt system will serve you just fine 98% of the time and save weight and money. I ran a 12 volt system in a 17 Pathfinder and it worked just fine for me.
 

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Discussion Starter · #7 ·
I am in Charleston, looks like you are as well. I have never owned a TM so not sure yet. I flyfish a good bit around the low tide and many times solo I am hoping that by adding a TM I will cover more ground
 

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The further the run from the TM batteries to the TM, the more sense it makes to run higher voltage. You could go unorthodox and run two batteries in 24v for the TM and use one of those batteries for the starter/house. I would add in a low voltage disconnect (LVD) which isn't terribly expensive.

You can create a fairly sophisticated setup with only two batteries including running the house off one, the starter off another, the TM off both in 24v and have the motor charge both batteries while running with an auto charging relay (ACR). That setup is not much more than three batteries ($150-ish) and you recharge all the batteries while running. Another bonus is your TM will never be able to fully discharge your batteries thus prolonging their life.

LVD: https://www.boatandrvaccessories.com/products/cole-hersee-48513-disconnect

ACR: https://www.bluesea.com/products/7601/m-Series__Automatic_Charging_Relay_-_12_24V_DC_65A

Now I am thinking it is time to dump a battery and clean up my setup.
 

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I had a 12v with a group 31 on my Ankona copperhead. The battery was mounted in a removable cooler. At the time I wasn’t using it much so 12v made sense and I was able to get it cheap.

Even in that light skiff it would be dead after 4-5 hours on the beachfront where as the 24v on my maverick 18 will last one full day of moderate use.

As an FYI I don’t use mine all day, just go get between dead areas and to get off the beach sandbar’s in a last minute scenario.
 

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I’ve run both... while I miss the all day hammering the 80 24v, the 12v 55 gets the job done. Like others have said if you can deal with the weight the 24 it definitely gives you more than you’ll need to fish all day hard. I put an Optima blue top on the 12v and it lasts till about 6-7 hours of hard running.

Main disadvantage of the 24 is reliability. If you have a charger issue or anything with one of the batteries it usually doesn’t show until you really need it. Out of 2 years I had at least 3 or 4 times it would not work in the water. 12 v never has never failed in over a year.

17 bohemian with f70
 

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I know you said you weren't ready to go lithium, but if you really do your research you will find that the cost is only slightly higher than a quality AGM battery for comparable performance. For instance you don't need to buy a 100ah lithium battery to perfrorm the same as a 100ah lead battery. I put a 12v lithium battery in my 17' skiff to run my trolling motor almost a year ago and no regrets.
 

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In my 18' sterling, i was running a 24V system with group 24 size batteries. They lasted all day with heavy sight fishing all on the trolling motor. I have since gone to Lithium's. I bought them online from china. $230 a piece plus 200 shipping. They are 60AH batteries @ 19# a piece. I have fished 2 long days straight on these with out charging and have yet to see an issue.
 

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Discussion Starter · #14 ·
Thanks guys for all for your feedback. It sounds like I can realistically get 4 hours or more with a 12v system using grp 29/31 battery and keep this simple and reliable.
I really appreciate how quickly and thoughtfully you all have chimed in. What a great resource this is.
 

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Discussion Starter · #15 ·
Tjtfishin and elusive porpi. Are you guys still running agm house battery and only lithium for TM’s? If I went 12v and wanted better performance than a 100ah/200 RC min group 31 battery what size lithium would do that. If I didn’t misunderstand it sounds like I could go 1/2 the ah rating and outperform. That would be huge. I did not realize lithium’s were priced there, would you be willing to share your source
Thanks
 

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I am currently using a AGM as my house battery. But my next battery will be a lithium. As i bought the batteries from China, this was a trail run for them and didnt want to sink too much money into this. Looking back at the shipping cost, i should have just bought a 3rd battery and be done with it.

AH wise, my research shows lead acid can run down to 50% and Lithiums' down to 15% usable AH's. So there is a ~35% gain in usable AH's in Lithiums.
As I've stated earlier, I couldn't kill the 60AH lithiums in 2 days of fishing.
These batteries also charge incredibly fast. After the 2 days of fishing, each battery charged in 2.5 hrs a piece. From what i read, lithioms can charge very fast with no side effects to the battery.

As far as source, It was off Alibaba. the link is below.
Looking back at my reciept, the total shipped to my house, which took 37 days, was $774.50. This includes 2x 60AH 12V batteries, and a 20 Amp single bank charger.
https://www.alibaba.com/product-det...779.html?spm=a2700.8443308.0.0.10853e5f6jUYcS

THese are the batteries installed in my boat. they are smaller than a group 24




US $248.0000

 

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Motor Guide Xi5 non-GPS trolling motor on my BT Mosquito. 12-volt, 55# thrust powered by an Odyssey AGM. Have yet to see anything less than a full charge indicator even after using it extensively throughout the day, although rarely on full power. Plenty of oomph for creeks and strong currents. Charged with a solar panel set-up. Light weight and effective.
 

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I have a deep cycle wet cell marine battery for my house. It is in the center console and used for cranking as well as GPS, bilge, livewell, lights, etc. I have the TM power in the front hatch.

I bought from a local company Lithium Ion Technologies which has the batteries made in China. Another local company Green Life buys the same batteries from the same factory. I'm sure there are others doing the same thing. The 12v trolling motor drop in replacement they suggest is the 50ah battery which gives comparable performance to a 100ah lead battery. Without getting into a technology monologue or sparking a big debate...as Elusive Porpi says lead batteries can effectively discharge to about 50%. Any lower and the output significantly drops making them useless from a practical standpoint. Additionally discharging wet cell batteries below 50% and AGM batteries below 75% significantly lowers their effective life. A LI battery can provide full output all the way until they are discharged to 85-90% at which point an internal Battery Management System controller shuts them down.

As far as cost, the price is about 2x the price of a high quality AGM such as an Optima Blue Top or similar. But an expected 10 times more discharge/recharge cycle life justifies the higher price in my opinion.
 

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Please note lithium batteries have serious hazards associated with them. If they are overcharged, they can catch fire and essentially melt a boat. They have internal charging circuitry that is required to regulate the charging cycle unlike a lead acid battery. A failure in that internal regulator can easily cause a fire. Lithium itself will catch fire when exposed to water as well.

Their have been recent airplane fires due to lithium issues. Samsung notoriously had lithium battery issues that set phones on fire. Lithium batteries are an impressive technology but it is still a new technology that comes with additional risks. Given the rate of equipment failure on a boat (water intrusion, vibration, etc) I would be very cautious about new technology that can effectively sink a boat in seconds.

Also something to keep in mind if a lithium battery catches fire, pretty much nothing puts it out until the entire battery is consumed. A fire extinguisher is of no use.
 

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Please note lithium batteries have serious hazards associated with them. If they are overcharged, they can catch fire and essentially melt a boat. They have internal charging circuitry that is required to regulate the charging cycle unlike a lead acid battery. A failure in that internal regulator can easily cause a fire. Lithium itself will catch fire when exposed to water as well.

Their have been recent airplane fires due to lithium issues. Samsung notoriously had lithium battery issues that set phones on fire. Lithium batteries are an impressive technology but it is still a new technology that comes with additional risks. Given the rate of equipment failure on a boat (water intrusion, vibration, etc) I would be very cautious about new technology that can effectively sink a boat in seconds.

Also something to keep in mind if a lithium battery catches fire, pretty much nothing puts it out until the entire battery is consumed. A fire extinguisher is of no use.
This is a blanket statement which severally exaggerates any issues. Every cell phone in the WORLD has lithium batteries in it. That is probably a billion phones. Yes there are bad batteries, just like anything else. I have also seen lead acid batteries explode in cars and equipment as well. These were also Lithium-Ion Batteries, not Lithium Iron Phosphate batteries. The lithium-iron battery has superior chemical and thermal stability.

These batteries are also tested and certified CE,UL,MSDS,Test Report from National Center For Quality Supervision and Inspection of Battery Products approved
 
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