Newbie - +ve terminal is toast - what could have caused this

[chrisski]

Just my thoughts, and not worth much. Does it look like it could have burned from the inside out?

Seeing some battery disassembly videos, I cringe when I see the wire size that manufacturers put from the terminals to the cells. However these terminals are connected are important also. The lug should lie on flat on the terminal for conductor to conductor contact and not have a steel washer between them. I also believe that a continuously rated for 45 amps of output is not put to that test very often, for very long. Seems like the response you got was beating around the bush like, “It’s rated to 50 ah continuous, but you really didn’t expect more than a couple minutes at that did you?” Also there is whatever amps the motor spiked to, like frequent increases in speed or going over debris.

Would be interesting to see an after picture of the terminals that were hooked to it.

 

[12VoltInstalls]

The continuous output current of your thruster is 45A, and the continuous output current of the battery must be at least 90A to solve the problem. The continuous output current of the 12.8V 50AH lifepo4 battery is 50A, which cannot meet your needs

Unless they are adding neg(-) and pos(+) current for their rating which neither makes sense nor is honest output.

Also there is whatever amps the motor spiked to, like frequent increases in speed or going over debris.

He did mention he has a 50A fuse. The response he got from them, however, really
makes no sense to me.

They are offering a refund.

Not a replacement? … hmm.
If you go with buying another of the same this could be a fun way to see what’s going on.

At the same time, a 50Ah battery really only gives you about one hour at full thrust and two hours at half-thrust so maybe a bigger battery (that SOK Will recently reviewed) will serve you better anyway.

 

[fakdaddy]

Unless they are adding neg(-) and pos(+) current for their rating which neither makes sense nor is honest output.

He did mention he has a 50A fuse. The response he got from them, however, really
makes no sense to me.

Not a replacement? … hmm.
If you go with buying another of the same this could be a fun way to see what’s going on.

At the same time, a 50Ah battery really only gives you about one hour at full thrust and two hours at half-thrust so maybe a bigger battery (that SOK Will recently reviewed) will serve you better anyway.

One thing I did notice is that the spec sheet on amazon says 45A max. However the spec sheet on the main website says 55A. hmmmm.

I just bough this to to do an inline monitor as Im running

https://www.amazon.com/gp/product/B07Z398YWF/ref=crt_ewc_title_oth_1?ie=UTF8&psc=1&smid=AZ0MMPOLVYF3T

Will see what the true DC amp draw is at full speed against water current.

 

[12VoltInstalls]

just bough this to to do an inline monitor as Im running

FWIW the Klein isn’t much more money

 

[fakdaddy]

That one only does AC amp meter

 

[12VoltInstalls]

That one only does AC amp meter

Weird. Well that was the link out my Amazon history. I had to search a minute but try this one. That’s the model number on the one I have. It does do DC amps. Not sure what happened. The price has gone up too.

 

[HRTKD]

@fakdaddy , do you have a link to the exact NOCO charger you used? I tried to find a NOCO charger that specifically understands how to charge LiFePO4 and couldn't find it.

 

[fakdaddy]

well .....
dc meter shows under no load 2A only
can only get it over 25-30A almost stopping the motor with my foot .........

will try on actual boat against water sometime

reached out to otehr battery companies - they all said the 50ah will be fine.

 

[fakdaddy]

@fakdaddy , do you have a link to the exact NOCO charger you used? I tried to find a NOCO charger that specifically understands how to charge LiFePO4 and couldn't find it.

Amazon.com

 

[HRTKD]

Amazon.com

View attachment 78323

Yeah, I wouldn't use that for my LiFePO4 battery. It would be OK for a temporary solution, but I wouldn't use it long term. It's an all-in-one solution, for any battery type. It doesn't actually KNOW what battery type you have. On the off chance that it thinks it is dealing with a lead acid battery that needs to be desulfated, your LiFePO4 battery isn't going to like the resulting voltage.

I was using a NOCO battery charger on my AGM batteries. It wasn't the best charge profile because AGM wants a bit higher voltage. I had to go through a reconditioning of the battery with a completely different charger that is specific to AGM to get my batteries back up to running well.

 

[Spliss]

With trolling motors i assume amps and thrust will be close to the same at high speed. If motor stalled (fishing line, log, etc) amps go much higher. Efficiency is pretty even i think amongst motor manufacturers so on my kayak my 35lb thrust runs about 35 amps at high no stall.
I wouldnt recommend testing your motor out of the water if you are as they can get hot.
I think you may have a combination of things here:
1. Higher amp draw than 50 amps.
2. Connections not great.
3. Battery construction (inferior bat wire awg) for high amp draw. The bms may not be so hot either if assumed amp draw was higher than 50 amps but did not trip.

Do you have a heavy kayak that requires 55lb thrust? I have a hobie outback with tons of crap on it when i fish and use 35lb thrust. My best hull speed is 5-5.5 mph. 55lb would not make me any faster.

I would get a larger bat for 55 lb. Good luck and have fun!

 

[fakdaddy]

Yeah, I wouldn't use that for my LiFePO4 battery. It would be OK for a temporary solution, but I wouldn't use it long term. It's an all-in-one solution, for any battery type. It doesn't actually KNOW what battery type you have. On the off chance that it thinks it is dealing with a lead acid battery that needs to be desulfated, your LiFePO4 battery isn't going to like the resulting voltage.

I was using a NOCO battery charger on my AGM batteries. It wasn't the best charge profile because AGM wants a bit higher voltage. I had to go through a reconditioning of the battery with a completely different charger that is specific to AGM to get my batteries back up to running well.

Not sure what you mean- can you elaborate.
It has a LIFEPO4 (lithium with BMS) setting and always negotiated to that when connected.

 

[fakdaddy]

With trolling motors i assume amps and thrust will be close to the same at high speed. If motor stalled (fishing line, log, etc) amps go much higher. Efficiency is pretty even i think amongst motor manufacturers so on my kayak my 35lb thrust runs about 35 amps at high no stall.
I wouldnt recommend testing your motor out of the water if you are as they can get hot.
I think you may have a combination of things here:
1. Higher amp draw than 50 amps.
2. Connections not great.
3. Battery construction (inferior bat wire awg) for high amp draw. The bms may not be so hot either if assumed amp draw was higher than 50 amps but did not trip.

Do you have a heavy kayak that requires 55lb thrust? I have a hobie outback with tons of crap on it when i fish and use 35lb thrust. My best hull speed is 5-5.5 mph. 55lb would not make me any faster.

I would get a larger bat for 55 lb. Good luck and have fun!

Yes a big kayak Kaku

Will test on water.

 

[Spliss]

Our kayaks are similar sizes, i am curious about your hull speed (top end speed)?
I put my bat inside hull in dry bag with diy installed connection to motor for protection. You could maybe put your bat in small cooler for better waterproofing? Less corrosion?

 

[HRTKD]

Not sure what you mean- can you elaborate.
It has a LIFEPO4 (lithium with BMS) setting and always negotiated to that when connected.

I'm used to my NOCO charger that has buttons for specific modes, not a mode button itself. Yes, you can specify a Lithium charge profile, so I was wrong. It's 14.6 volts at 5 amps. If your LiFePO4 battery is very low on state of charge, it could take up to 10 hours to bring it to 100%, possibly even longer if the charger drops down to a float voltage after X number of minutes. The user guide doesn't say what the charge profile is other than 14.6 volts at 5 amps.

 

[12VoltInstalls]

dc meter shows under no load 2A only
can only get it over 25-30A almost stopping the motor with my foot .........

Did you recharge the battery first?
What was the voltage when you tested?

If the battery could take a charge that is a good omen.

hull speed (top end speed)

Hull speed or ‘max speed?’

1. Higher amp draw than 50 amps

he said he has a 50A fuse so that shouldn’t be an issue with it.

 

[HRTKD]

he said he has a 50A fuse so that shouldn’t be an issue with it.

Yes, but do we trust the fuse? I haven't seen the specs for it.

 

[Spliss]

Did you recharge the battery first?
What was the voltage when you tested?

If the battery could take a charge that is a good omen.


Hull speed or ‘max speed?’

he said he has a 50A fuse so that shouldn’t be an issue with it.

About 5 mph with 35lb minnkota (pwm) and 5.5 mph torqueedo. Different type motors, minnkota can push alot of weight, my torqueedo is made more for speed. Top end for both about the same under same conditions.
Not sure what fuse he uses but i also use 50 amp fuse and its a cheap pos lol.

Sorry off topic..
I think there is a real possibilty that the connection to the positive stud inside battery may be crappy.
Do they want the battery back for a refund? If not id rip it open and check it out.

 

[12VoltInstalls]

My best hull speed

About 5 mph with 35lb minnkota (pwm) and 5.5 mph torqueed…%…Top end for both about the same under same conditions

Hull speed isn’t top speed. It’s the speed where the bow wave frequency equals the waterline LOA. Attempts to go exceed that speed and you actually start climbing the bow wave - the LOA/beam of a kayak seems as though it wouldn’t be trying to plane at just 5mph? I dunno. I’ve never seen anyone try to porpoise a kayak

For equal input (amps, watts) the difference in top speed is the prop pitch and/or diameter.

reached out to otehr battery companies - they all said the 50ah will be fine.

The motor had been running all day on and off. I didnt notice the smell until towards end of the trip. It was running at full speed.
50A fuse never blew.

So as spliss mentioned: do you have to send it back for a refund? If no send-back then carefully cutting open the case should be done to examine internally for safety and perhaps repair any damage. Or if there’s like 10ga wire from the internal 12V to the terminal replace with 6ga if there’s space. Just make sure it can’t get afire and melt a rectangular hull drain in the thing.

Yes, but do we trust the fuse? I haven't seen the specs for it.

It would be good to know what fuse are you using? (Does minnkota actually sell fuses these days?!)
I’m assuming it’s another brand than minnkota

Your 25-30A results aren’t what i’d expect for a fully charged battery.