# What's going on with this battery?



## pennstater2005 (Jul 17, 2017)

50amp hour SLA battery. Negative post got hot and partially melted. It's also swelling a bit.

This has been charged with a Noco charger and used inside a battery box for a trolling motor.

Any ideas? Don't see any frayed wires.


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## dicko1 (Oct 25, 2019)

Poor connection at the - terminal. A little resistance under heavy current gets hot and melts the case.


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## TheCutShop (Jun 24, 2021)

Discharge rate or charge rate is too fast. I doubt the charge rate is too high. Most likely the current going to the trolling motor is too high. Most batteries have a max discharge and charge rate listed (C- value.)


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## pennstater2005 (Jul 17, 2017)

****o1 said:


> Poor connection at the - terminal. A little resistance under heavy current gets hot and melts the case.


What do I need to do there?


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## pennstater2005 (Jul 17, 2017)

TheCutShop said:


> Discharge rate or charge rate is too fast. I doubt the charge rate is too high. Most likely the current going to the trolling motor is too high. Most batteries have a max discharge and charge rate listed (C- value.)


What can I do here?


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## FlowRider (Apr 7, 2019)

I know exactly what that battery needs.

A decent burial. :rofl: :crazy:

Or recycle it, even better.

Warranty claim might also be an option....


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## Thick n Dense (May 7, 2019)

Get a volt meter and see if its holding a charge. 
Might be toast now like 
@FlowRider said due to damage.

To me looks like some sort of event happened, like a short circuit... yea the plastic is melted but the cathode is blew up (compre to + terminal).

Check the amps required. And make sure battery is suitable for the need.

Also check your fuse... looks like it didnt blow. Supposed to protect the system. Which means most likely incorrect size


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## pennstater2005 (Jul 17, 2017)

The trolling motor draws 52 amp hour. This is a 50ah battery. I had gone to a pretty reputable battery dealer near me and he said the 50ah would be fine.

Can I clean up the terminal and get new connections? I hate to waste $100 but don't want a fire on the water.


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## pennstater2005 (Jul 17, 2017)

Also, Noco Genius 5 charger. Emailed them to see if the charger could be faulty and overcharging it.


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## TheCutShop (Jun 24, 2021)

If the trolling motor pulls 50a and runs for one hour that would be 50 amp hour. A good rule is to not discharge below 80% on a lead acid battery. Which is a little over ten minutes of run time before needing a charge with your current battery. In my opinion the battery is way too small. 
If you have to carry the battery to the boat every time you use it, get the biggest you can safely carry. If you leave it in the boat a group 31 battery has good value because it's very common in commercial vehicles and tractors.

AGM batteries have less internal resistance so the can discharge and charge faster without overheating.

I would study/familiarize yourself with max charge and discharge rates to size a battery for the duration you would like to use the trolling motor.


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## pennstater2005 (Jul 17, 2017)

TheCutShop said:


> If the trolling motor pulls 50a and runs for one hour that would be 50 amp hour. A good rule is to not discharge below 80% on a lead acid battery. Which is a little over ten minutes of run time before needing a charge with your current battery. In my opinion the battery is way too small.
> If you have to carry the battery to the boat every time you use it, get the biggest you can safely carry. If you leave it in the boat a group 31 battery has good value because it's very common in commercial vehicles and tractors.
> 
> AGM batteries have less internal resistance so the can discharge and charge faster without overheating.
> ...


That's good info. We generally go out for about an hour but not running on full speed the whole time. A 100ah would be feasible but what would runtime be?

Thanks


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## Automate (Aug 14, 2020)

The amp hours tell you how much total charge the battery will hold whereas the amps tell you how much current (and therefore power) the battery can supply. That battery is only rated for 15 amps. Need to check the maximum amps your trolling motor needs.


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## pennstater2005 (Jul 17, 2017)

Automate said:


> The amp hours tell you how much total charge the battery will hold whereas the amps tell you how much current (and therefore power) the battery can supply. That battery is only rated for 15 amps. Need to check the maximum amps your trolling motor needs.


It is rated at 50 amps maximum. So what battery would be better? The Mighty Max 100ah battery is rated at 30 amps initial draw. I'm a bit confused.


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## Automate (Aug 14, 2020)

pennstater2005 said:


> Automate said:
> 
> 
> > The amp hours tell you how much total charge the battery will hold whereas the amps tell you how much current (and therefore power) the battery can supply. That battery is only rated for 15 amps. Need to check the maximum amps your trolling motor needs.
> ...


The picture you posted of the failed battery say "Less than 15A" (amps). What does your trolling motor need?


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## pennstater2005 (Jul 17, 2017)

The Minn Kota Endura C2 55# thrust noted 50amp maximum. That's all I could find on it.


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## pennstater2005 (Jul 17, 2017)

I might just ditch the batteries, sell the Minn Kota, and go 2.3 hp Honda. I've seen some pretty sweet rigs for Excursion 5. I honestly don't want to go any heavier on batteries as the 100ah is about 60 lbs.

Honda small outboard weights 29.5 lbs.


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## Automate (Aug 14, 2020)

pennstater2005 said:


> I might just ditch the batteries, sell the Minn Kota, and go 2.3 hp Honda. I've seen some pretty sweet rigs for Excursion 5. I honestly don't want to go any heavier on batteries as the 100ah is about 60 lbs.
> 
> Honda small outboard weights 29.5 lbs.


FYI, the Excursion 5 is only rated for 1.5 HP but I'm not surprised if people are putting larger motors on it.


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## pennstater2005 (Jul 17, 2017)

Automate said:


> pennstater2005 said:
> 
> 
> > I might just ditch the batteries, sell the Minn Kota, and go 2.3 hp Honda. I've seen some pretty sweet rigs for Excursion 5. I honestly don't want to go any heavier on batteries as the 100ah is about 60 lbs.
> ...


Yep. It pulls the motor under a bit even with the trolling motor at highest setting. But, with some ingenious bracing they seem to work well. Thanks for your input.

Do you think I could still use that battery but keep the motor on its mid setting or less?


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## FlowRider (Apr 7, 2019)

I used to power a Minn Kota trolling motor on a 22 foot Sweetwater
(Godfrey Marine) pontoon boat for freshwater fishing using deep cycle marine batteries. Would run all day if you used the Yamaha Thrust 60 motor for any big moves.

I also used to use lithium batteries to power lights on motorcycles. @Ware may know about this technology since he used to ride Honda XR650Rs.

Before you pony up the money to put a gas engine on your inflatable, you might want to try this option first:

https://dakotalithium.com/our-batteries/

Nanotechnology solution that would solve your problems….


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## FlowRider (Apr 7, 2019)

Friends who live on sailboats in the Bahamas use these batteries.

You can get lighter weight models designed for kayaks and small boats.

https://m.youtube.com/watch?v=2gm9fx-_6ug


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## pennstater2005 (Jul 17, 2017)

FlowRider said:


> Friends who live on sailboats in the Bahamas use these batteries.
> 
> You can get lighter weight models designed for kayaks and small boats.


I've seen those but they're crazy expensive. I was looking at 200ah and some of those run near a thousand dollars. I'm leaning toward taking the boat out myself after cleaning the terminal and running the motor at mid speed or less. It has 5 settings so 3 or less and just keep my eye on the battery.

If need be I could row back :roll:

I just don't want to be out of this battery after just a month or so of usage. Plus, I have a 35ah hour backup that I took as well.


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## FlowRider (Apr 7, 2019)

To me, if you are using the battery for transportation over water, I would want the best battery I can get, especially if you have passengers….

Getting stranded because your battery died can be dangerous, and if a storm blows up, things get out of control very quickly with no power….

I always had two fully charged batteries on my boats or jet skis. You can have a very bad day with a bunch of ticked off people on board. On my boat I used for passenger cruising or fishing, I always had two engines. You can limp home on one motor and make it back to your dock if one engine dies. I have done it before, when low on fuel. I went to a marina to get fuel, but they ran out. I got home by switching to a reserve tank and using only one motor to get back.

Laughing at what happened over dinner beats paddling back any day.

I would spend the money, personally, but it is your decision, Captain!

I hope whatever you decide to do works out for you!

Did you try and get the dealer to warranty the battery? Maybe they can help you devise a solution.

I wire my own boats and so I do things that cost a little more sometimes but if it means I get back home when things malfunction it is worth it. I usually have guests on board, so I've learned to build in backups….

Best of luck with your solution!


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## pennstater2005 (Jul 17, 2017)

@FlowRider

Thanks for the suggestions. It has a one year warranty but you have to pay shipping!!

With a trolling motor can I use any deep cycle marine battery?


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## FlowRider (Apr 7, 2019)

pennstater2005 said:


> @FlowRider
> 
> Thanks for the suggestions. It has a one year warranty but you have to pay shipping!!
> 
> With a trolling motor can I use any deep cycle marine battery?


You may want to check - in my experience, if you pay for shipping, and they honor the warranty, they will/may reimburse you for the return shipping costs when they send you a new battery....

You can use any deep cycle battery with a trolling motor, but you need to consider the reserve capacity (RC) and amp hours, which are both listed on the battery or website. I would go with 100 amp hours. Additional limiting factors are cost, weight, space, charger type/cost, and battery size.

I had room to carry two batteries, and also used dual purpose batteries on the engine starting circuit. I had to run sonar with transducers, fish finders, GPS, stereo, boat lighting, spotlights, marine radio, live well pumps and aerators, powered winches for striped bass downriggers, margarita blender (yeah, it's a booze cruise thing with the ladies, and "that guy") and cell phone USB chargers. You can run the batteries down pretty quick with all that, which is why I always carried backups.

On an inflatable you need to keep the weight manageable, but I am not sure how you use your boat. If you are just putting around for grins and family fun, I would live with the weight and lower costs.

I would also use flooded acid cell batteries, if you can handle them. You can add distilled water to keep the battery electrolyte levels topped up, and they are easiest to charge with a battery tender. They make waterproof battery tenders, too, if you need that capability. I charged mine overnight.

Battery power is vitally important on a boat. And it can save your life in a sudden thunderstorm....

I put everything inside battery boxes that were strapped down, although flipping a pontoon is almost unheard of. But I have been blindsided by rogue waves more than once, so I strapped it all down....


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## Amoo316 (Jul 8, 2021)

Just as a qualifier I Bass Fish as a second job. Trying to run a trolling motor on a lead acid, non-deep cycle battery is asking for the same problem over and over again (assuming you don't want to go lithium). Minn Kota actually has really good CS compared to a lot of other companies I have dealt with. I would legit call them and ask in your situation what kind and size battery they recommend for that trolling motor. I would guess they recommend something like a 1300ah deep cycle, but I would still ask them.


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## pennstater2005 (Jul 17, 2017)

FlowRider said:


> pennstater2005 said:
> 
> 
> > @FlowRider
> ...


I'll call Mighty Max to double check the warranty. I did contact Minn Kota to see if they had any advice. We are using it just to fish and float around mostly.

I found a 105ah hour battery with 210 min reserve so may look into that. I am only powering the boat and nothing else although the battery box does have a USB and 12 volt port.

Thanks for all the insight!


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## pennstater2005 (Jul 17, 2017)

Going to run a little test to see if the battery gets hot. How important are torque specs for the hardware onto the battery posts?


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## pennstater2005 (Jul 17, 2017)

Ran on high for ten minutes. Battery terminal never got hot even with only 3/4 of the post left. Contacted the Noco charging company. See what they say. I may try that and see if it gets hot after being on the charger.


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## Automate (Aug 14, 2020)

pennstater2005 said:


> Ran on high for ten minutes. Battery terminal never got hot even with only 3/4 of the post left. Contacted the Noco charging company. See what they say. I may try that and see if it gets hot after being on the charger.


Without the load of water/boat the motor is probably not pulling a lot of amps. You could maybe take the boat out for a test spin and check the battery terminal temperature often.

It could have been you didn't have a good connecting and the resistance caused some localized heating.

You also could add a circuit breaker between the battery and the motor as extra protection.


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## pennstater2005 (Jul 17, 2017)

Automate said:


> pennstater2005 said:
> 
> 
> > Ran on high for ten minutes. Battery terminal never got hot even with only 3/4 of the post left. Contacted the Noco charging company. See what they say. I may try that and see if it gets hot after being on the charger.
> ...


True. Didn't think of that. I'll consider the circuit breaker. If all else fails I can put that battery in the kids dune buggy. I've already modified it but that 50ah hour would go all day. Of course unless it's a fire hazard.


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