lithium battery ?

[wadeboyzfishing]

I replaced my 3 lead battery's with a 36v lipo question i have is , has any one ever put the battery in bow to lessen even more weight from the rear. i run a 36v minn kota w/ 12'" mega 360 up front.

 

my boat is really stern heavy and trying to lessen the load. thanks.

[Woody B]

You lightened the stern by replacing the lead batteries.   I'm sure people have put them in the front.   I've got the opposite problem.  I lost most of my bow lift by going lithium.   It's not a big deal, I've got a 17 foot aluminum boat with a 50hp motor.   I believe it's on the edge of being too light in the stern, or too heavy on the bow.   I normally cruise at 4500 rpm.... I don't run around wide open.  Wide open trimmed yada yada yada it's 1 1/2 mph faster (39mph) with a fuel tank of fuel, compared to a couple gallons.   I don't have enough power to lift the bow weight with the lighter stern.   

[airshot]

Rearrainge your gear, I also run a 16' aluminum boat with two group 31 batteries in front, spent a lot of time figgering the load placement

[WIGuide]

I'm sure guys have done that before. Before making a permanent change put the battery up there and run it to see what happens. Regardless, depending on how your boat runs you might want to consider having some prop work done or run an entire different prop all together.  There's a lot of reports out there about people losing speed when switching to lithium batteries like woody's above. A lot of that has to do with prop design and the relationship to balance/leverage. Generally speaking props with more blade area create more stern lift and props with more rake tend to generate more bow lift. A boat that's set up properly and runs well with weight in the back may suffer when the weight is removed due to too much upward force on the transom which in turn pushes the bow down.  

[gim]

On 2/3/2023 at 7:29 PM, Woody B said:

I've got a 17 foot aluminum boat with a 50hp motor

I'm fairly surprised you can go 39 mph with that setup.  I have a 17.5 foot aluminum boat with a 75 outboard and I can only go about 34 mph.

[Woody B]

6 hours ago, gimruis said:

I'm fairly surprised you can go 39 mph with that setup.  I have a 17.5 foot aluminum boat with a 75 outboard and I can only go about 34 mph.

 

Your Ranger is 14 inches longer, and 15 inches wider than my Tracker.  It's probably several hundred pounds heavier too.   Best GPS speed on mine was 39.1 mph when it was dead calm.  I can get 37.5 after going to lithium.   Like I said earlier, I cruise at 4500 rpm.  I'm not in a hurry.   

[gim]

50 minutes ago, Woody B said:

 

Your Ranger is 14 inches longer, and 15 inches wider than my Tracker.  It's probably several hundred pounds heavier too.   Best GPS speed on mine was 39.1 mph when it was dead calm.  I can get 37.5 after going to lithium.   Like I said earlier, I cruise at 4500 rpm.  I'm not in a hurry.   

Yes, but I’ve also got 25 more horses in my stable. Sluggish would be the word to describe it. What kind of prop are you running?

[Woody B]

55 minutes ago, gimruis said:

What kind of prop are you running?

10.375 dia, 14 pitch.  Stainless with cupping.  35mph  with the stock aluminum 10.375 X14 before I damaged it.  

[WIGuide]

17 hours ago, gimruis said:

Yes, but I’ve also got 25 more horses in my stable. Sluggish would be the word to describe it. What kind of prop are you running?

Although your boat is longer and wider, it sounds like your setup is leaving a little on the table. a lot of reports I'm seeing are showing numbers in the upper 30's and low 40's with the 75.

[Tennessee Boy]

I mounted a LiFePO4 battery under my console because I didn’t have room in the back.  It has worked well.  When I replace my trolling motor batteries I will probably rearrange things and move it to the back.  I would be a little worried about putting an expensive lithium battery at the bow where it will take more of a beating in rough water.  Also are you sure you won’t need more capacity in the future?  Going from 3 batteries to one had to lower your total amp hours.

[gim]

Perhaps this is not directly related to this thread, but I received a flyer in the mail yesterday for Cabela's and they are having a Marine Sale this month, Feb 9-22.  On one page has a size 27 AGM deep cycle battery for only $139, normal price is $200.  If hadn't just replaced my batteries in the last 2 years, I would seriously consider this upgrade.  A standard lead acid battery is at least $100, if not more.

 

The Tracker lithium versions are $499 each.  That is still too steep for me.

 

https://www.cabelas.com/shop/en/shop-our-catalogs?guideKey=4F9A5FD6-098B-4C44-8E93-51374D1C1D3C#catalog/bass-pro-shops-create-marine-sale-event-29-thru-222-3-5470/page/1

[flyfisher]

On 2/7/2023 at 1:46 PM, Tennessee Boy said:

I mounted a LiFePO4 battery under my console because I didn’t have room in the back.  It has worked well.  When I replace my trolling motor batteries I will probably rearrange things and move it to the back.  I would be a little worried about putting an expensive lithium battery at the bow where it will take more of a beating in rough water.  Also are you sure you won’t need more capacity in the future?  Going from 3 batteries to one had to lower your total amp hours.

I doubt it because he said he went to one 36V so i am guessing we have a series situation to get the required 36V.  The other thing to consider when going lithium is you get a lot more usable voltage.  I can take my Li batteries to 10% and they are full strength up to that point.