Battery box power station

[berger]

i have a battery box for my battery and it has the battery guage on it and two 12v adapter plugs. well i noticed one time i got the blade stuck on the trolling motor one day while i was out and it blew the fuse on the battery box. its a 30 amp fuse i replaced the fuse and took it out fishing and was using the trolling motor and the trolling motor would stop then start again it eventually blew the fuse again just curious what is causing the fuse to blow cuz it says you can use the outside connectors for a trolling motor

 

[Ictalurus]

Replace the 30 amp with a 50 amp fuse and you should be fine.

 

[berger]

ok will do thanks

 

[linehand]

Replace the 30 amp with a 50 amp fuse and you should be fine.

Was it blowing fuses before you overloaded it?....larger fuse could solve but there may be an underlying problem.... Stick a shunt in her and look for the smoke..lol

 

[berger]

no it never blew the fuses before the only time it started i was in shallow water and got the blade stuck in the mud and it blew the fuse and i have noticed when u connect the trolling motor to the batteries they get kinda hot

 

[linehand]

no it never blew the fuses before the only time it started i was in shallow water and got the blade stuck in the mud and it blew the fuse and i have noticed when u connect the trolling motor to the batteries they get kinda hot

Hate to say it but souinds like you cooked something. Do what you want, but if it was in my hands I would look into it and find out what is causing the problem.

 

[TNtroller]

may have melted some wire insulation when you got it stuck, and is now causing a short due to the bare wire exposed, which blows the fuse. I would inspect every inch of the TM wiring, something is not right.

 

[wihil]

Just a couple things -

Uprating the fuse from a 30 to a 50 isn't solving the problem - if anything it could cause more issues down the road.

Fuses can blow for many reasons, but the one underlying reason is more current than the circuit is designed to handle. Something is loading down the circuit and causing the fuse to go.

A lot of people will immediately jump to a "short", but if that were the case your motor wouldn't start/stop/start/stop before the fuse went. If it was a short the fuse would blow immediately the moment you put it back into the circuit.

The fact your motor is start/stop/starting would point me in the direction of the motor itself - the battery is getting hot because it's trying to dump current into the motor to make it go.

Without knowing what happened and going off what you've said so far, I'm betting that:

1) The motor has reduced resistance (less resistance, more current to drive it = fuse poof!) in it from when the motor was stalled, damaging the coils and reducing the motor's internal resistance

2) The motor has a thermal sensor in it and see it getting hot, so it stops it to prevent it from damaging itself.

3) Motor turns back on, current is too high

4) Fuse blows.

OR -

You've got a bad battery - the motor stalled in the mud, draining the battery and it wasn't charged up immediately afterward/it was an old wetcell battery and was starting to get tired. Even after charging you've got a float charge of 12V, but the actual capacity is much less so you when you apply the load (motor) it starves the battery of voltage (low voltage = high current) and the motor sees this causing the motor to start/stop as the voltage drops too low (eg, 11v runs, 9v's stops causing the battery to recover to 11v, and the motor runs again), and eventually there's not enough voltage to run it which spikes the current and the fuse blows.

The first option is a bit of an issue to troubleshoot, but the second option is as easy as pulling the battery down to Autozone or where ever and having them load test the battery for free.

Just a couple idea's for you.

C

 

[linehand]

Just a couple things -

Uprating the fuse from a 30 to a 50 isn't solving the problem - if anything it could cause more issues down the road.

Fuses can blow for many reasons, but the one underlying reason is more current than the circuit is designed to handle. Something is loading down the circuit and causing the fuse to go.

A lot of people will immediately jump to a "short", but if that were the case your motor wouldn't start/stop/start/stop before the fuse went. If it was a short the fuse would blow immediately the moment you put it back into the circuit.

The fact your motor is start/stop/starting would point me in the direction of the motor itself - the battery is getting hot because it's trying to dump current into the motor to make it go.

Without knowing what happened and going off what you've said so far, I'm betting that:

1) The motor has reduced resistance (less resistance, more current to drive it = fuse poof!) in it from when the motor was stalled, damaging the coils and reducing the motor's internal resistance

2) The motor has a thermal sensor in it and see it getting hot, so it stops it to prevent it from damaging itself.

3) Motor turns back on, current is too high

4) Fuse blows.

OR -

You've got a bad battery - the motor stalled in the mud, draining the battery and it wasn't charged up immediately afterward/it was an old wetcell battery and was starting to get tired. Even after charging you've got a float charge of 12V, but the actual capacity is much less so you when you apply the load (motor) it starves the battery of voltage (low voltage = high current) and the motor sees this causing the motor to start/stop as the voltage drops too low (eg, 11v runs, 9v's stops causing the battery to recover to 11v, and the motor runs again), and eventually there's not enough voltage to run it which spikes the current and the fuse blows.

The first option is a bit of an issue to troubleshoot, but the second option is as easy as pulling the battery down to Autozone or where ever and having them load test the battery for free.

Just a couple idea's for you.

C

Not trying to question an EE but you stated: 1) The motor has reduced resistance (less resistance, more current to drive it = fuse poof!) in it from when the motor was stalled, damaging the coils and reducing the motor's internal resistance
To me that doesn't make sense. Did you mean increased resistance like a failed open or near open in the windings or brushes? Causing the high current to make the fuse fail?
I also think the issue could be with the switch contacts burned up. They are made so cheap anymore I have seen them fail before the motor damages itself.

 

[Jonboat Jerry]

may have melted some wire insulation when you got it stuck, and is now causing a short due to the bare wire exposed, which blows the fuse. I would inspect every inch of the TM wiring, something is not right.

Also check the switch and the connectors for melted plastic allowing the contacts to touch momentarily.
I would resist putting a bigger fuse in it as it could cause a meltdown/fire. My 2c

 

[wihil]

Linehand - you can question me anytime you want! I'm human, I make mistakes (and I don't work on high powered DC motors much at all, I work with little stuff that goes beep a lot)

Doesn't happen all the time, but I've seen in high current motors where if the motor stalls/stops the current will burn out some of the winding's sheaths (that lacquer coating on the cheapo motors, but not all of them) and fuse them resulting in a lower impedance coil. Lower impedance on one side of the windings = unbalanced load = more current, draw you get the idea. Again, doesn't happen often at all - but I've seen it on big stuff.

AFA the failed open, if that were true the motor wouldn't start/stop/start - it'd just be dead.

I like the contacts burning up idea too - there's a lot of junk electronics out there. It's not made like it once was..

C

 

[Zum]

Just curious.
What size trolling motor do you have and are you just hooking the trolling motors wires,directly to the battery(no extra wiring)?
If your using some type of plug and using the 12V plug on them boxes,I doubt it could handle that many amps for long,with the wires they use.
Did you take the prop off the TM and check for line,even weeds around the shaft?

I've had a circuit breaker(50amp cheapy) go bad(weak)on me before,were it produced the same symptoms you are describing.
There are a few things to check.
Heres alittle chart to see what amperage your TM might be drawing.

 

[berger]

i figured out the problem. i thought the outside terminals would run a trolling motor but it cant run the trolling motor or start the motor its just a charger terminal or some other sort of hook up

 

[Jonboat Jerry]

Glad you found it, they can drive you nuts at times.