Advice on Onboard Charger - Blowing Dock Fuse

[JetBoatPenguin]

Looking for advice from the group . . .
I have 2 Duracell Marine Group 31M AGM batteries on board the Yamaha.
I bought a Minn Kota Precision MK 330PC (3 x 10 amp) onboard charger to charge them.
I had 2 of the 3 lines attached to the house battery.
The boat is on a shared pier with about 9 slips on it....
When I plug in my charger - it blows the pier circuit breaker.
Others on the pier have boat lifts and chargers plugged in.

I guess my charger pulls too many amps when combined with the other loads being pulled at the dock by my neighbors.

I wanted a 10amp per bank charge given the batteries are AGM.

Any 2 bank alternative charger with a lower amp pull the forum would recommend? Or ideas on how to troubleshoot avoid blowing the dock circuit breaker?
Genius
ProSport
?
When all the other boats are unplugged . . . my charger still blows the dock circuit breaker.
There are two breakers 20 amp each.

I was concerned about charging the AGM batteries at a rate lower than 10amps per bank . . .based on other forum threads.

Thanks....

 

[ZGhost]

That sounds odd, there must be some other reason? Perhaps it has to do with the socket at your slip? are you running an extension cable? Is that of proper gauge and rating for the Minn Kota? Check the user manual, I have the same charger and I recall it specifying extension cable specs.
also, try plugging that Minn kota at another slip electrical socket to see if it does the same thing. Not sure if you have that option but worth checking.

 

[ZGhost]

Here is some info from the manual, looks like it only draws 7.2 amps?

 

[JetBoatPenguin]

Thanks to the wiser people in the group. I'll check the gauge of the extension cord. Maybe I'll need to drop down to the 220PC as well to keep my neighbors happy.

 

[FSH 210 Sport]

Check the outlet plug with a volt meter to see if the voltage I’d correct, low voltage leads to higher amp draw.

As @ZGhost shows, your charger at full load, 120 volts is only 7.2 amps.

Have you tried plugging in to another outlet fed from another breaker to see if that works? Sometimes breakers get weak and they trip much lower than their rating. And, are the breakers GFCI type breakers? Those are pretty sensitive.

I have the same charger as you, plus a MK 220 PC, fed by a 100’ 16 gauge extension cord that is fed from a 20 amp breaker in the shop and no issues.

 

[JetBoatPenguin]

Check the outlet plug with a volt meter to see if the voltage I’d correct, low voltage leads to higher amp draw.

As @ZGhost shows, your charger at full load, 120 volts is only 7.2 amps.

Have you tried plugging in to another outlet fed from another breaker to see if that works? Sometimes breakers get weak and they trip much lower than their rating. And, are the breakers GFCI type breakers? Those are pretty sensitive.

I have the same charger as you, plus a MK 220 PC, fed by a 100’ 16 gauge extension cord that is fed from a 20 amp breaker in the shop and no issues.

I'll give it a go again with the VoltMeter to see when I drop it in next...boat slip is 100 minutes away and remote. I thought it might be a weak breaker as well...but will start with using a 12 gauge new extension cord. Then the volt meter.... I can also get the owners of the pier to upgrade go 25 amps...which may help too if its weak.

 

[FSH 210 Sport]

I'll give it a go again with the VoltMeter to see when I drop it in next...boat slip is 100 minutes away and remote. I thought it might be a weak breaker as well...but will start with using a 12 gauge new extension cord. Then the volt meter.... I can also get the owners of the pier to upgrade go 25 amps...which may help too if its weak.

Just to clarify, what I mean by a week breaker is one that is worn out, tripped too many times due to high loads, or perhaps if not rated for a wet atmosphere has become defective over time.

I respectfully suggest you try the charger in a different outlet after verifying the voltage is close to 120 volts. If the other breaker doesn’t trip when you plug in you know it’s the breaker. A 20 A breaker should be more than sufficient for this load. Hmmmm, need to also make sure there is no other load on that breaker as well.

 

[ZGhost]

I would definitely first investigate and troubleshoot causes other than the charger drawing too many amps. Buying another charger may not be the solution as the difference could only be roughly 2 to 4 amps. Besides why would you throw away a perfectly working top notch charger? I bet the issue is in the outlet or extension cord. Last resort, ask them to rectify the issue. You pay for a slip with power service, it should work. I’ve owned this charger and plugged in many different outlets and used extension cords with no issues.
One last thing, you can bring other devices that draw different amperage and plug them in to test your amp draw theory. Ex.. heater, fan, hair dryer, radio, etc. just make sure you how many amps each supposed to draw. If they trip the circuit, try plugging them into other slips outlets and if they don’t trip those, then it’s definitely your outlet.