Not using fuses ??? (on-board charger)

[TNFL]

Are fuses necessary on an on board charger?  Manual chargers do not have them,  is there a reason for them on the on board charges.

I was given a system with a bank that may not have been working correctly, possibly blowing the fuse repeatedly.  My system would not be hooked up to an alternator on the engine so I'm wondering if it is fine to use the charging bank without the fuses. 

The orange charging light comes on when I hook the wires directly up to a battery.

I'm asking because I don't want to go through the bother of wiring this thing in my boat if I can't get it to work right.

Also, I would technically only need 2 of the 3 banks to work, but I like the idea of repairing it to its potential.

[h8go4s]

Fuses are for fire protection. If you're willing to risk a fire in your boat if something goes awry, have at it. Your insurance company would be happy to have a good reason to keep all the premiums you've paid and refuse your claim. Hopefully no one will get injured or die in the fire.

[delcecchi]

13 hours ago, h8go4s said:

Fuses are for fire protection. If you're willing to risk a fire in your boat if something goes awry, have at it. Your insurance company would be happy to have a good reason to keep all the premiums you've paid and refuse your claim. Hopefully no one will get injured or die in the fire.

The line feeding the charger should be fused, but typically the charger connects to a line that is fused already in the boat wiring.  

The output of the charger is protected internally to the charger.  

And I have never seen a policy or company refuse to pay just because it was your fault.  They pay for fires from pans left on stoves, for space heaters with 16ga extension cords run under the rug, etc.  

I think all this "insurance won't pay" is just a myth.  

 

In the case of the charger outputs to the batteries, not sure where the fuses would be located.. At the battery?  Not sure what the fuse would be protecting.  I guess it depends on where the charger is located and where the batteries are. 

[h8go4s]

Here's a quote from the MinnKota digital onboard charge manual.

"INLINE FUSE

The output cord has an inline fuse on the RED end. The fuse serves as protection from surges and short circuits caused

by a damaged charger output cable. If a fuse blows, replace it with a 30 amp ATC 32V automotive fuse. Improper battery

connections will normally not cause a fuse to blow since this is handled by the internal circuitry of the charger."

[papadarv]

On ‎8‎/‎20‎/‎2017 at 5:46 PM, TNFL said:

Are fuses necessary on an on board charger?  Manual chargers do not have them,  is there a reason for them on the on board charges.

I was given a system with a bank that may not have been working correctly, possibly blowing the fuse repeatedly.  My system would not be hooked up to an alternator on the engine so I'm wondering if it is fine to use the charging bank without the fuses. 

The orange charging light comes on when I hook the wires directly up to a battery.

Fuses are blowing for a reason most likely an undesirable reason. Much better solution to fix the problem than eliminating the fuse. Eventually the sort or item causing the fuse to blow will eventually make it to the wires. Just a thought, although not recommend, there is enough battery current where you can stick weld 11 gage steel with a 12 volt battery. Continued or prolonged welding (same as a short) could cause to battery to explode. Word of caution, led acid batteries are filled with sulfuric acid. 

[Surface Tension]

So all 3 banks are blowing fuses with the charger outside the boat hooked to a battery with nothing else connected to it?  

Try a different battery.  If your still blowing fuses I wouldn't use the charger.

 

[BobT]

On 8/20/2017 at 5:46 PM, TNFL said:

Are fuses necessary on an on board charger?  Manual chargers do not have them,  is there a reason for them on the on board charges.

I was given a system with a bank that may not have been working correctly, possibly blowing the fuse repeatedly.  My system would not be hooked up to an alternator on the engine so I'm wondering if it is fine to use the charging bank without the fuses. 

The orange charging light comes on when I hook the wires directly up to a battery.

I'm asking because I don't want to go through the bother of wiring this thing in my boat if I can't get it to work right.

Also, I would technically only need 2 of the 3 banks to work, but I like the idea of repairing it to its potential.

The purpose for having fuses is to protect the wires and/or downstream devices from over-current situations. When an over-current situation exists the wires can be exposed to higher current than what they are rated to handle and the resulting heat will likely melt the insulation and possibly cause it to burst into flame, which can spread to an on-board fire destroying your boat and everything in it. 

A fuse that repeatedly blows when replaced is a good indicator that there is a situation that needs to be resolved. You need to find out what is causing the over-current situation and resolve it. Putting in a higher rated fuse does NOT solve the problem. The wires are rated to a maximum current level and the over-sized fuse will allow excessive current to flow over the wires, which is no better than just getting rid of the fuses. Do not do this.  

[Wanderer]

The OP was given the system by someone else who was having problems with it.

@TNFL

If the above statement is correct, try it on your system and see if the fuse blows.  The problem may have been on the other person's rig.  

Is it worth contacting the manufacturer for tech help or sending in for testing/service?