24v Trolling Motor on a 20' Pontoon

[pixolia]

Hello!

I have a 24v pontoon trolling motor that is a few years old that I bought used a few years back. I'm finally getting to the point of mounting it but need some new batteries for it. My only real use for it would be to putz around during the fireworks display on the 4th on our lake as we drift a lot and to also be available as an emergency solution if something happens to go wrong with my main motor. My main motor will always be the primary option and the main go to but stranger things have happened and I feel it's safe and smart just to have a backup as on our lake we don't have any coast guard or someone to call if I need a tow. I figure I have the troller anyway so I might as well mount it and have it for backup. Its I think a 65lb thrust pontoon specific minn Kota.

I found these batteries at my local fleet farm and wanted to get someone opinion on if two of these will be good in case my boat dies a few miles away from my slip or for just some general midnight creeping around without using a noisy motor. I have a 20' smokercraft pontoon and will be mounting it on the front of the boat.

I realize bigger batteries are better BUT I'm more concerned about weight too as I have to lug these things up a hill and across a busy street to get to my slip and for how I plan to use it I'm not sure I need something bigger or not. These are only 41lbs versus the more standard 60lbs..

Here's the battery I'm considering, please let me know your thoughts - https://www.fleetfarm.com/detail/road-runner-marine-starting-deep-cycle-battery/0000000079893

It's a m34agm. I'd be buying 2 and running them together for the 24v obviously.

Thanks for your input!

 

[HotTommy]

I'm going to have to do a lot of assuming here, so please correct any guesses that are wrong.

• I assume the 34AGM battery is rated for 34 amp-hours at 12 volts.
• Two such batteries in series would be rated at 34 amp-hours at 24 volts.
• Your trolling motor likely has am amp rating somewhere. Divide 34 by that number and it will tell you how long your batteries will last in hours.
• According to one source, a 40-70 pounds thrust trolling motor operating at full power will use about 40 amp-hours. So your batteries would last about 50 minutes in that case.
• If that's enough for your putting around or occasional rescue, then those batteries could do.

I had a spare trolling motor and thought of finding a way to carry it on my 24' pontoon boat in case of main engine failure. It turns out that if the wind is blowing much more than 10 MPH, the boat is going to go to the downwind shore of my lake no matter what the trolling motor is trying to do. Once I get to the shore, the problem is half solved. So I gave up on the trolling motor idea. I have been stranded twice in the last five years and a friendly passing boater towed me home (about a mile) both times.

 

[Silvertip]

No -- the 34 is the group size (physical size) of the battery. AGM is the battery chemestry. These in my view would be overkill if used as indicated and especially on a smaller lake. You might check Fleet Farm again for conventional flooded deep cycle batteries. Just the other day I saw them (group size 27) for 80 bucks. Two of those for the price of one AGM. I've used Fleet Farm batteries for decades and have always had excellent service from them. The group size 34 would likely have about 185 - 200 minute reserve capacity at a current draw of 25 amps. That motor will work just fine for its intended purpose. I used a smaller motor (55#) 12 volt on a 20 footer and wind was never an issue. For trolling in the wind, troll backwards using the motor to slow the boat rate.

 

[pixolia]

Hello! Thanks for the information. The biggest issue for me right now honestly would be battery weight. The max distance I'd really ever have to go to safely make it back home in any event of main engine malfunction would be 3-5 miles.. I measured distance from one launch to the other across the lake and it comes in at about 3 miles, so actually on the water I'd say 4-5 to be safe. I want something with the lowest weight ratio I can get, preferably no more than 40-45lbs. Based on that assumption and information, what do you think I would need so that I can get back safely even if I have to putz and limp my way back but still make it without needing a tow? I guess it would also be a good battery that I could potentially drain and not fully ruin if that's the case as I'd hate to blow those batteries on one dumb malfunction.

Would that group 27 (2 in series) from fleet you mentioned work for my 70lb thrust 24v pontoon troller on my 20' boat? I'm not on lake Michigan or an overly huge lake, but it isn't small either.

I think my minn kota motor has a max amp draw of 42 from my findings.

I don't like the price as much but do like the fact that these batteries seem to be saying they ship at 32lbs weight which would be an ideal weight for me - https://www.amazon.com/VMAXTANKS-MR...tor-Trolling/dp/B009UE6NY4?tag=fisfinsou09-20

Would those via the Amazon link I sent above work? Would it be a stretch? Would it be overkill? I plan to use my minn kota for emergency reasons or just some late night cruising around the shoreline fishing for a few hours.

Sorry if my messages are redundant, I've just been researching this for awhile and buying 2 batteries will set me back a bit so I just want to do all the research I can.

Thanks!
Mike

 

[HotTommy]

Get the amp-hour rating for one of your 12 volt batteries and divide that by 42. That will tell you how many hours your two batteries will power your 24 volt trolling motor at full thrust. I can't tell you how far that will take you because it depends on the boat, its total weight, winds and currents.

 

[pixolia]

Ok, thanks for the info. I was looking into a sealed battery so I don't have to worry about leaks like the last 2 I had did at the end of their lives. However, the sealed ones are a little more expensive than I was looking to spend and in theory, I'm not sure if it's really a huge deal if I use battery boxes anyway so it catches there versus my seat storage compartment. So based on the logic of the AH divided by the max output of amps, if I bought a battery like this one - https://www.batteriesplus.com/batte...ose-(starting_cycling)/bci-group-24m/sli24mdp

...That's 65AH / 42 max output of my minn kota 24v would give me about an hour and a half at WOT? So half speed which would make more sense would put me close to 3 hours or run-time? If that's the case and I can output 3MPH it would take roughly 1 hour to go 3 miles. I figure 3 miles would be the absolute max I'd have to travel when on the lake I'd be on to safely get back to shore. These batteries are 42lbs which is one of the bigger selling points for me as well. I'd go bigger but weight is just the annoyance.

Thoughts based on my logic and does that seem reasonable?

The batteries via the link above are deep cycle AND starting, I figure this way I can maybe universally use these batteries as a backup to start my main motor if I feel that's a viable option, or to run my lights or other electronics, etc. I'd go full deep cycle as the same version of this battery above for DC is 75AH so it's a little more. But then I'd be limited to what I could do with them, which I'm not fully opposed to but I'd like to think the trolling back to shore would be my absolute desperation move after other options are ruled out.

As for the caps and leakage, is that common with these types of batteries? How long do you think they'd last with usage maybe 15-20 times throughout the summer? How often would I have to maintain batteries like this in terms of re-filling the cells, etc?

Thanks!

 

[HotTommy]

Your math sounds good to me. The only thing that might concern me is the effect of wind on your MPH. A good stiff breeze could ruin all you calculations, but at least you could steer some in whatever direction the wind wanted to take you.

 

[randy ussery]

pixolia, I have a 24v wireless trolling motor on my 18' toon and it works great. there is no better setup as far as im concerned. I have plenty of reserve power with a 24v system and can troll for crappie for several full days before recharging the batts, and or bass fish for over a solid week before charging. The weight of an extra batt is nothing and had no effect of the trim or level static floatation of the toon and when the wind or currents are strong, you have ample reserve thrust to power up and continue to fish while others with 12v systems have to give it up..

 

[clemsonfor]

A 34lb batter won't have much energy in it at all. And and flooded acid battery you discharge more than 50% will shorten it's life. Your suppose to only discharge to the 50% rate for normal service. To get you back in a no power situation it would be obviously acceptable to drain them as much as possible t get back. Also lead acid batteries like to be kept at top charge of float charge for the longest life possible.

 

[clemsonfor]

Oh and those batteris with proper care and charging should last 5 years. Might have to fill them once a year after the first. But don't over charge them and boil them over and that helps.

 

[bruceb58]

Might have to fill them once a year after the first. But don't over charge them and boil them over and that helps.

They are AGM batteries.

 

[clemsonfor]

They are AGM batteries.

Ha yea those you wouldnt but I thought we were mixing in flooded acid batteries in the mix too.

 

[clemsonfor]

[url]http://forums.iboats.com/member/490384-pixoliapixolia,[/URL] I have a 24v wireless trolling motor on my 18' toon and it works great. there is no better setup as far as im concerned. I have plenty of reserve power with a 24v system and can troll for crappie for several full days before recharging the batts, and or bass fish for over a solid week before charging. The weight of an extra batt is nothing and had no effect of the trim or level static floatation of the toon and when the wind or currents are strong, you have ample reserve thrust to power up and continue to fish while others with 12v systems have to give it up..

You still want to charge the batteries after every ise to maximize their life. Flooded acid deep cells have no "memory" like nicad or others and they last the longest wheen there kept full or slightly over 100% in float charge state.