36V System – Battery Challenges

Hi All,

Here’s the setup – 1850 Reata with 112 Terrova. Run 3 Interstate 27 Series batteries to support the TM. Minnkota MK460 4 bank charger. In 2 years I’ve chewed up 3 batteries. They require water added about every 60 days and constant attention to make sure they don’t run dry. I leave the boat on the charger at almost all times when not in use. No issues on the cranking battery.

Wondering if there is anything else I can do….I don’t like the lead acid batteries and the maintenance. I’m not sure if larger will fit in the Reata. Filling with water is a pain….requires removing all the batteries to get at them.

Most of my time is on the river….maybe it is what it is given how hard I am on the batteries. For example, I trolled upstream in heavy current yesterday at 8-9 on Terrova for a few hours. Rest of the 8 hours was in spot lock on current.

I need to call the SBC guys, too. That’s where I bought the boat and they may have some ideas. Maybe AGM’s are a better bet because they are low maintenance. Any other thoughts/ideas/suggestions? I feel like I need a spare battery on board at all times.

AGM all the way. I will never buy a lead-acid battery again. They cost more but last longer.
One thing to check is the MK460 charger can be set to battery type. Maybe you are using the wrong charging profile.

Matt Moen wrote:

For example, I trolled upstream in heavy current yesterday at 8-9 on Terrova for a few hours.

You ever feel your power wires after doing that? I’ll bet they are quite warm and soft! Grab the plug. This is why i don’t do it on mine. Yes i have proper gauge.

Do you have a kicker? Anytime i am above a 5 i turn on the kicker. It isn’t good to run that much juice for long periods. You can even run the kicker when spotlocked, again, i do when spotlock is above a 5.

I go through 2 group 31’s every 2 years with my usage, which is on the extreme high end of near daily use. They aren’t shot, but they are beyond my use at that point. Adding water isn’t necessary on mine though, they’re never low. The difference might be never running above a 5.

I also get about the same years on the two gp 31’s that run everything else in the boat. Big graphs must be a big drain. I simply have no tolerance for running short on batteries, so they get tossed when they’re showing a loss, determined by a load tester.

FishBlood&RiverMud wrote:

<div class=”d4p-bbt-quote-title”>Matt Moen wrote:</div>
For example, I trolled upstream in heavy current yesterday at 8-9 on Terrova for a few hours.

You ever feel your power wires after doing that? I’ll bet they are quite warm and soft! Grab the plug. This is why i don’t do it on mine. Yes i have proper gauge.

Do you have a kicker? Anytime i am above a 5 i turn on the kicker. It isn’t good to run that much juice for long periods. You can even run the kicker when spotlocked, again, i do when spotlock is above a 5.

I go through 2 group 31’s every 2 years with my usage, which is on the extreme high end of near daily use. They aren’t shot, but they are beyond my use at that point. Adding water isn’t necessary on mine though, they’re never low. The difference might be never running above a 5.

I also get about the same years on the two gp 31’s that run everything else in the boat. Big graphs must be a big drain. I simply have no tolerance for running short on batteries, so they get tossed when they’re showing a loss, determined by a load tester.

I don’t have a room for a kicker but maybe it’s time to ditch the Talon and just get it over with. All I was thinking yesterday was “man, sure would be nice to have a kicker right now.”

SLA batteries have 3 problems: (1) High discharge rates cause deterioration, (2) high discharge rates result in lower usable capacity per charge, and (3) over-discharging causes deterioration.

You should get more than 300 charge cycles out of an SLA under normal circumstances.

I have a load tester if you want to test them.

You have one talon?
What’s on the other side?

JasonP wrote:

SLA batteries have 3 problems: (1) High discharge rates cause deterioration, (2) high discharge rates result in lower usable capacity per charge, and (3) over-discharging causes deterioration.

You should get more than 300 charge cycles out of an SLA under normal circumstances.

I have a load tester if you want to test them.

Just need you to chauffuer me aroud the river…..keep the Ranger for booze cruises.

Matt Moen wrote:

<div class=”d4p-bbt-quote-title”>JasonP wrote:</div>
SLA batteries have 3 problems: (1) High discharge rates cause deterioration, (2) high discharge rates result in lower usable capacity per charge, and (3) over-discharging causes deterioration.

You should get more than 300 charge cycles out of an SLA under normal circumstances.

I have a load tester if you want to test them.

Just need you to chauffuer me aroud the river…..keep the Ranger for booze cruises.

Join the jon boat guild!!!

I’m surprised you can get three group 27’s in the front of an 1850. I have two group 31’s in the front of mine and they are a major pain to remove to check the water. The batteries are due to be replaced this year and I will probably go AGM for that reason alone.

If you really wanted long, maintenance free juice you could go even further to a lithium battery. The price tag is pretty steep though.

Could you have some bad banks on your charger? 2 or 3 banks could be bad and are overcharging your batteries causing them to boil and the one on your starting battery could be working fine.

Can’t help with your batteries but yes, AGM are worth it. Put them in your boat once and never touch them again for 5 years (I get 9-10 but I don’t run half as hard as you do). You don’t need to trickle charge them either, or during winter storage. Once they are charged, they stay charged for months and months.

Heavy monkeybutts but great batteries!

Ron F wrote:

I’m surprised you can get three group 27’s in the front of an 1850. I have two group 31’s in the front of mine and they are a major pain to remove to check the water. The batteries are due to be replaced this year and I will probably go AGM for that reason alone.

It’s tight but 2 fit in the back and then a single in the front of the compartment. You need a pry bar and a stick of butter to get everything out of there though!

FishBlood&RiverMud wrote:

You have one talon?
What’s on the other side?

Swim ladder…..much more important than the talon when you have a 6 year old!

Matt Moen wrote:

<div class=”d4p-bbt-quote-title”>FishBlood&RiverMud wrote:</div>
You have one talon?
What’s on the other side?

Swim ladder…..much more important than the talon when you have a 6 year old!

I went with a 4 hp tohatsu pull start because it weighed in at a whopping 50#. Clamp on to transom.
on and off in two minutes.

My daughter likes to kneeboard and tube.

Not familiar with your transom. But I’d bet you can figure out a way to quick attach the kicker or swim ladder. Then you’ve got all 3 bud!!

I would bet your charger is cooking the batterys leading to failure. Not all bank chargers have a float or maintain once charged.

Ns wrote:

I would bet your charger is cooking the batterys leading to failure. Not all bank chargers have a float or maintain once charged.

Something seams off. I do not add nearly as much water as you are and do not go though batteries like that. I run pretty hard but if the spot allows anything over 6-7 on TM for extended period kicker is in gear.

What it is coming down to is that you are charging, even if in maintenance cycle, and that will keep heating the water in the batteries, you should be able to unplug the charger after about 12 to 14 hours of charge after a very long hard day of fishing.

As an example of this is— put a pot of water on a stove and turn it on low and let it go for days on end and see what happens. At some point the water will be gone.

The same thing is going on in your battery’s when you keep the charger on them and you need to keep adding water.

For context, I run a 24V system with lead acid batteries while primarily fishing the river.

Something seems strange for your setup. I do not run my trolling motor much beyond 5 or 6 continuously as the wires do get hot even with the appropriate gauge (so overall not heavy use). The charger in the boat is from 2010 and gets plugged in after each outing (twice a week). With all that said, my batteries last 5-6 years easily and I have room to add a few tea spoons of water at most every other season. In the offseason the batteries stay right in the boat in a 40 degree garage with the onboard charger plugged in once a month or so to top things off.

Ns wrote:

I would bet your charger is cooking the batterys leading to failure. Not all bank chargers have a float or maintain once charged.

I’ll check it out….it’s still under warranty. It’s odd that the batteries haven’t all gone….it’s been different banks all spaced out over 2 + years.

The Minnkota is supposed to go into sleep mode and only kick back on once the voltage drops below 12.6. But, maybe that’s not working and that’s part of the reason.

I think you’re running them too hard and getting the results of such activity.

If you start your boat and check your voltage from your depthfinders, and it is never above 14/15 volts. Your charger is working fine.

Matt Moen wrote:

<div class=”d4p-bbt-quote-title”>Ns wrote:</div>
I would bet your charger is cooking the batterys leading to failure. Not all bank chargers have a float or maintain once charged.

I’ll check it out….it’s still under warranty. It’s odd that the batteries haven’t all gone….it’s been different banks all spaced out over 2 + years.

The Minnkota is supposed to go into sleep mode and only kick back on once the voltage drops below 12.6. But, maybe that’s not working and that’s part of the reason.

Not uncommon for different banks to go out at different times. That is why al three batteries should be replaced at the same time. The system is only as good as the weakest point.