Lithium Batteries / charger for Boat

[brookie]

Okay, here is the next battery/charging question - charging 2 12 volt batteries in series. I have always had a 12 volt trolling motor, but am looking at a 24 volt so the 24 volt system is new to me. I know that 2 12 volt batteries in series make 24 volts. So how do you charge the batteries? Will a 2 bank 12 volt charger, one bank for each battery work? With a 2 bank charger do you need to disconnect the two batteries from each other to charge or have an on/off switch between or can they stay wired together in 24V and just hook up 1 12V bank to each battery? Do Li ion batteries make a difference here?

The short answer is yes, one bank for each battery and no you do not need to disconnect the two batteries because they are hooked up different on the 24 v system vs 2, 12 v hooked up in series. Can't help you on the  Li ion, I'm not ready to make that jump yet, until my old batteries go out.

Thanks Curt, was just a little afraid of putting 12V charger into a 24V system - wanted an outside opinion. (2 12V batteries hooded up in series is the 24V system)

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Okay, here is the next battery/charging question - charging 2 12 volt batteries in series. I have always had a 12 volt trolling motor, but am looking at a 24 volt so the 24 volt system is new to me. I know that 2 12 volt batteries in series make 24 volts. So how do you charge the batteries? Will a 2 bank 12 volt charger, one bank for each battery work? With a 2 bank charger do you need to disconnect the two batteries from each other to charge or have an on/off switch between or can they stay wired together in 24V and just hook up 1 12V bank to each battery? Do Li ion batteries make a difference here?

So how do you charge the batteries?  Hook bank 1 to battery 1; bank 2 to battery 2

Will a 2 bank 12 volt charger, one bank for each battery work?  Yes, that is the way they are designed to work.

With a 2 bank charger do you need to disconnect the two batteries from each other to charge or have an on/off switch between or can they stay wired together in 24V and just hook up 1 12V bank to each battery?  They do not have to be disconnected or have an on/off switch.  Hook separate banks to each battery - bank 1 to battery 1; bank 2 to battery 2

Do Li ion batteries make a difference here?  None whatsoever other than the charger must be compatible with lithium batteries.

Thanks Bob, that answers all my questions. You guys are great. When you need answers, just go to the experience on BFT

[SkunkedAgain]

So just to wrap up my questions that started stuff off, this is what I've found out.... One the batteries look great and at $236 vs $105 for my starting battery new from Sam's... I think the Lithium's are going to really take off... The AGM at Sam's was more than my Lithiums, so I went flooded cell for my starting motor and LiFePO4's for the trolling batteries... I got a NOCO 3 bank charger 5amp per bank... Talked to battery Mfg and they verified it was okay to charge with the lower than 20 amps they recommend. They said it will just take longer to charge.. It was really hard to find that little piece of info that wasn't just someone guessing... But their guesses were correct.. The charger is really nice, put it on the 3 batteries and it topped off the starting battery really quick, the Lithiums are only about half charged so far. One point that was brought up during this discussion was how to store your lithium batteries charge wise. Turns out you store your lead acids fully charged, but Lithiums should be stored at 50% charge, that is like 13.15 Volts.. This has to do with where the battery positions electrons and in the Li you want them mid way to keep from degrading the batteries over a longer storage period. They said you should not put a trickle charger on the Lithium's but if they get lower than the 50% then you should charge them back to 50% charge... Charger has two leads for each battery, so will hook it up to each battery and it should just charge that battery... Don't remember what else I asked, but I think I'm ready to try the boat with new batteries and a bow mount motor, so I should get quite the education tomorrow, not to mention slick tires on the truck... Hope we don't have a tale of woe to tell tomorrow night... Later Jeff

[wiperhunter2]

Jeff said,"Lithiums should be stored at 50% charge, that is like 13.15 Volts.."How can 50 % of the charge be 13.15 v are you talking about 50% of the charge for 24 v system?  If you are talking about 50% of a 12 v battery, shouldn't that be 6 v?

[a_bow_nut]

It might be fifty percent of the operating range.

[Marble-eyes]

Jeff,

Dubob is correct; the only con with lithium batteries is charging during freezing temps. A friend who installs off grid solar systems claims you shouldn’t charge when below 32 deg.
I used the same batteries (100ah) you have after ice out on the Bear earlier this year, 18 foot aluminum, spot locked in the current for approximately 3-4 hours, two days in a row, never recharged after first day. I had 60% battery life left after using for two days! You’ll be very happy. And the weight difference is almost unbelievable!

[SkunkedAgain]

Jeff said,"Lithiums should be stored at 50% charge, that is like 13.15 Volts.."How can 50 % of the charge be 13.15 v are you talking about 50% of the charge for 24 v system?  If you are talking about 50% of a 12 v battery, shouldn't that be 6 v?

Curt, it was kind of crazy how they showed the numbers. Anything above 13.33 volts is full charge, 10-12 volts is considered dead. 13-13.15 is 25%, 13.15-13.2 is 50%, 13.3-13.33 is 75% and greater than 13.33 is considered 100% charged. It’s a lithium thing on when the batteries have power to feed the system. So like mentioned it must be useable voltage. Later Jeff

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Jeff,

Dubob is correct; the only con with lithium batteries is charging during freezing temps. A friend who installs off grid solar systems claims you shouldn’t charge when below 32 deg.
I used the same batteries (100ah) you have after ice out on the Bear earlier this year, 18 foot aluminum, spot locked in the current for approximately 3-4 hours, two days in a row, never recharged after first day. I had 60% battery life left after using for two days! You’ll be very happy. And the weight difference is almost unbelievable!

Thank you that sounds really good, I’ll give them a try in the morning and report back. As far as weight goes, I nearly split a gut getting my old lead acid size 31’s out of the boat and these are feather light. Really like that part for sure. Might be the best thing for my health for sure. Not sure what I’m going to do to charge them during the winter, with no garage. Might have to pull them to charge, glad they’re light. Thanks for this info, much appreciated. Later Jeff

[BYUHunter]

A huge advantage of Lithium that is not discussed enough is the lack of "voltage sag". Meaning, as a Lithium battery discharges, it maintains over 13v of output for over 90% of it's output range. 

Conversely, conventional lead/acid and AGM batteries experience linear voltage sag, meaning they go from 13.3v, to 13v, to 12.6v, 12.2v, 11.9v etc as they discharge. You have to run your electric troller at higher settings as the battery discharges, to net the same output.

Additionally, you can almost completely discharge a Li battery without damage. On a lead/acid or AGM battery, even a deep cycle, discharge below 50%, and especially below 25%, really starts to permanently damage your battery capacity.

I would also like to STRONGLY disagree that the weight difference is insignificant. I have a 36v 100AH, which is equivalent to three group 31 lead/acid batteries in terms of capacity. A typical group 31 is 60-75 pounds, so we'll just be conservative and say 65 lbs. On a 36v system like mine (three batteries) that's 195 pounds, essentially an average man's weight. My 36v Li weighs 63 pounds. That's over 100 pounds of weight savings. Even in my big 27' Duckworth with a 300 HP Pro XS, it makes a difference. Not to mention the space savings of a single 36v Li, opposite having three enormous group 31's.

The only divantage? Li is more expensive (but the gap is closing) and they're a little pickier about charge temps, but a smart Li charger can factor for that.

Rant over.

[SkunkedAgain]

Report back, I had my first day on the water with the new batteries and wow that was nice to have them do what they are supposed to do and never fade... Only issue I had was they are long enough I can't put them cross wise in my battery compartment and they are too wide to go side by side, so I had to position them in opposite directions, but that comes from two big batteries size 31 I believe... they are about 14" long... But as far as performance goes, they were excellent... When I learn how to run my motor better, it will be really great, right now it was kind of a comic show watching me try to drive the boat... You guys never mentioned that driving a bow mount trolling motor is more difficult than it looks, requires a certain amount of waiting for the system to respond before you put further inputs into the system.. it also might be low batteries in the remote, but I have a learning curve of how to make the remote commands get to the motor and then getting the boat to do what I need to have happen... About now I'm really having an appreciation for the commercial when the guy back his boat in, it takes off on it's own and meets him at the dock where he steps in and goes fishing... Yeah right, that had to take some practice... Later Jeff

PS... I got the new to me bow mount troller last spring, but due to battery issues hadn't really been able to use it much until yesterday's trip..

[wiperhunter2]

Report back, I had my first day on the water with the new batteries and wow that was nice to have them do what they are supposed to do and never fade... Only issue I had was they are long enough I can't put them cross wise in my battery compartment and they are too wide to go side by side, so I had to position them in opposite directions, but that comes from two big batteries size 31 I believe... they are about 14" long... But as far as performance goes, they were excellent... When I learn how to run my motor better, it will be really great, right now it was kind of a comic show watching me try to drive the boat... You guys never mentioned that driving a bow mount trolling motor is more difficult than it looks, requires a certain amount of waiting for the system to respond before you put further inputs into the system.. it also might be low batteries in the remote, but I have a learning curve of how to make the remote commands get to the motor and then getting the boat to do what I need to have happen...  About now I'm really having an appreciation for the commercial when the guy back his boat in, it takes off on it's own and meets him at the dock where he steps in and goes fishing...  Yeah right, that had to take some practice... Later Jeff

PS... I got the new to me bow mount troller last spring, but due to battery issues hadn't really been able to use it much until yesterday's trip..

One of the first things I learned when I got Minnkota I pilot, when using it to steer, always hit the N button, which means you have it on a North heading, so were you turn it left or right, it will come back to a straight heading, instead of continuing to turn. I'm sure someone else can give you a better description but all you need to do is push that N button and it works much better.

[SkunkedAgain]

Thanks Curt, I'll have to look at it again, I don't remember the N, but it's probably there... I only had about 4-5 buttons that I could figure out what they did, so got a lot of learning to do... When I got the motor, I looked up and read the directions and thought it would be easy to figure out when I got it going... Welp either I forgot or it wasn't as intuitive as i thought... I know each zone applies to a different function, but I couldn't remember which was which... Will be nice once I understand what I'm telling it to do, but yesterday we were speaking different languages... Later Jeff

[wiperhunter2]

Thanks Curt, I'll have to look at it again, I don't remember the N, but it's probably there... I only had about 4-5 buttons that I could figure out what they did, so got a lot of learning to do... When I got the motor, I looked up and read the directions and thought it would be easy to figure out when I got it going... Welp either I forgot or it wasn't as intuitive as i thought... I know each zone applies to a different function, but I  couldn't remember which was which... Will be nice once I understand what I'm telling it to do, but yesterday we were speaking different languages...  Later Jeff

It really helps if you go out with someone that has the same remote control as you do. Ira had one before I did, so he told me how it should work but there are several different controls. When you get a chance, take a pic of your remote control and post it, that will make it easier for us to point out what you need to do.

[SkunkedAgain]

Hey Curt that's a good idea, I have the boat all covered up, but next time I think of it, and get a picture I'll try doing that... I'm hoping to try a Willard trip before it freezes up for the winter, so I'll try to remember then... Probably be at least a week from now before I get time to try that.. Later Jeff

[2knots]

Hey Curt that's a good idea, I have the boat all covered up, but next time I think of it, and get a picture I'll try doing that... I'm hoping to try a Willard trip before it freezes up for the winter, so I'll try to remember then... Probably be at least a week from now before I get time to try that.. Later Jeff

What motor did you get? Also I have found that during the winter put the remote in your truck and then pocket to keep it warm until you get to the lake, cold plays havoc with the batteries and performance.

[SkunkedAgain]

[quote pid="1150650" dateline="1702041920"]

Hey Curt that's a good idea, I have the boat all covered up, but next time I think of it, and get a picture I'll try doing that... I'm hoping to try a Willard trip before it freezes up for the winter, so I'll try to remember then... Probably be at least a week from now before I get time to try that.. Later Jeff

What motor did you get? Also I have found that during the winter put the remote in your truck and then pocket to keep it warm until you get to the lake, cold plays havoc with the batteries and performance.
[/quote]

Hey Alan, I got Pete's old Terrova, he upgraded to the new Ultrex and it worked good for me to be able to get into a Terrova so hopefully I can do better on trolling perch than we did last winter when the wind pushed me everywhere i didn't want to be.. Thanks for the suggestion on the remote batteries, I'm sure that will help... If I can just not forget to take it with me.. Maybe I'll pull it out of the boat before I drive to where I'm going to fish and have it warm by the time I get there... If I put it in the house I'm sure I'll forget it, so better keep it in the boat until I leave and then put it in the truck and warm it up on the way... Hope I can find time to get a Willard trip in before Christmas, that was fun last year... Later Jeff

[2knots]

[quote pid="1150650" dateline="1702041920"]

Hey Curt that's a good idea, I have the boat all covered up, but next time I think of it, and get a picture I'll try doing that... I'm hoping to try a Willard trip before it freezes up for the winter, so I'll try to remember then... Probably be at least a week from now before I get time to try that.. Later Jeff

What motor did you get? Also I have found that during the winter put the remote in your truck and then pocket to keep it warm until you get to the lake, cold plays havoc with the batteries and performance.

Hey Alan, I got Pete's old Terrova, he upgraded to the new Ultrex and it worked good for me to be able to get into a Terrova so hopefully I can do better on trolling perch than we did last winter when the wind pushed me everywhere i didn't want to be.. Thanks for the suggestion on the remote batteries, I'm sure that will help... If I can just not forget to take it with me.. Maybe I'll pull it out of the boat before I drive to where I'm going to fish and have it warm by the time I get there... If I put it in the house I'm sure I'll forget it, so better keep it in the boat until I leave and then put it in the truck and warm it up on the way... Hope I can find time to get a Willard trip in before Christmas, that was fun last year... Later Jeff
[/quote]
There should be a button with a capital N on it, when you press it the same symbol with a circle around it should show up on the remote screen, post the button again so that the circle is gone and just the N and it is much easier to control where you are going. 
I take my remote and put it in my pocket when I leave to go to the lake, it gets warmed up and it’s with me

[SkunkedAgain]

Thanks Alan, i'll try this and see if it makes a difference, I have a good short cut card somewhere, but I need to go through it again before I go out and I'm sure it will work a lot better... Thanks for the tips... so do you need to do the N on each trip, or does it stay set from trip to trip? Thanks Jeff

[2knots]

Thanks Alan, i'll try this and see if it makes a difference, I have a good short cut card somewhere, but I need to go through it again before I go out and I'm sure it will work a lot better... Thanks for the tips... so do you need to do the N on each trip, or does it stay set from trip to trip? Thanks Jeff

You need to do it every time you turn on the remote, so no it doesn’t stay that way

[SkunkedAgain]

Thank you, I'll have to learn to get in the habit so I remember... Thanks Jeff

[dubob]

Jeff,

You need to make YouTube your most watched computer URL this winter.  There are dozens upon dozens of videos on there that deal with all matters Minn Kota.  Here is one such video that details the two different Autopilot ('N' button) modes - Advanced & Legacy.

Minn Kota i-Pilot Autopilot Modes Explained: Advanced vs Legacy (youtube.com)

There are other on-the-water videos that show you how the Autopilot function works in real time.  I use Autopilot Advanced mode for 95% of my trolling.

I leave my remote in the glovebox on the boat and I always carry 2 or 3 spare remote batteries in the glovebox as well.  I think there are rechargeable versions of the remote that would require you to take the remote off the boat to recharge it, but I don't have that version.  If you don't as well, then just leave it on the boat all the time.

There is another function on the remote that can be helpful at times, but will discharge your trolling batteries faster.  That function is called 'Cruse Control'.  That function will try to maintain a set GPS speed for the boat regardless of current or wind.  Running against the wind or current will cause the trolling motor to increase motor rpm's to maintain the set speed.  Running with the wind or current will cause the motor rpm's to decrease or even shut off to maintain the set speed.  I use it sparingly so as not to drain my trolling motor batteries and shortening my usable batteries work time.

There are other functions that are helpful for aiding your fishing adventures while trolling or anchored.  As I said at the beginning, learn how to use the YouTube channel to your full advantage.  Good luck with your new toy.  See you one the ice - soon.  

[SkunkedAgain]

Thanks Bob, I think I need to watch them when I'm in the boat so I can try it at the same time, then maybe I'll remember it better and really learn how to run it... Great tip, it's a lot easier than reading the book and trying to figure out what they are saying.. Thanks and bring on the ice... Jeff