Onboard charger tripping gfi outlet

I’ve got a recurring issue and not sure why it’s happening. We have power at the dock that is routed to a gfi outlet up at the house. When I plug in my onboard charger at the dock it trips the gfi outlet. Here’s the history.

Had a 2 bank 5 amp for a few years, worked great(2014-2017). Upgraded boats and now a 3 bank x 5 amps (Minnkota MK315d).

2018, worked fine.
2019, worked fine.
2020, intermittent in May and then didn’t work. Replaced the gfi at the house and worked the rest of the season.
2021, worked to start in May then not working. Replaced the gfi again, worked about two times and now it’s not working.

I can use other power items at the dock. Low load things like a light. Can use a Schumacher 15amp portable charger without issues. That’s my workaround is to use the portable to charge one battery at a time.

Ideas???

When a GFCI outlet keeps tripping, there must be a reason. Instead of just resetting the GFCI, you should also investigate the cause of the trip. Ground faults occur when electrical current finds an unintended path to ground.

The problem is in your charger (of course). If your any good with diy, take the cover off and check the ground on the charger or it could be the cord/outlet that’s on the charger.

Someplace in the charger current is leaking.

I’d 1st grab my multimeter and eliminate whether or not the charger could be the culprit.

Is each bank charging adequately (>13 V) when charging?

Many IDO electronic wizards will help diagnose what’s up.

Grounding issues come to mind seeing how it’s intermittent.

What is the current rating for your GFI? If 15 amp it is probably too close to your current draw. Your wire size and lenght of run also enter into it. Check wire size tables for run length to make sure it is heavy enough. If wire size is 14 you can’t go over a 15 amp GFI so wire and GFI may be too light.Both breakers and GFI recepticles can degrade over time especially if used at maximun rating and are reset a few times.

Does it trip other GFCI outlet say at your house in the garage or does it work there? If you can try charging it on another GFCI with a short cord. The longer the cord the larger the voltage drop which increases the amp load on the GFCI. GfCI outlets will trip from over amperage draw also. I have also seen them get weaker over time and when you replace them they work again for a little while. So 2 things could be happening a over amp draw or voltage leaking to ground. When you plug the other items in is it to an extension cord from the outlet the same one you use to charge the boat?

I’ve had a similar problem at a resort we stay at for a week. I need 120 feet of cord to reach the boat. With 14 gauge cords I was tripping the GFCI. I switched to a 100′ 12 gauge cord along with 25′ 14 gauge and don’t trip the GFCI with a 10-10-6 3 bank charger.
I would try borrowing a 12 gauge extension cord because buying one is a big investment. If it works the investment is worth it.

Great suggestions, a little more background based on the responses

carnivore wrote:

What is the current rating for your GFI? If 15 amp it is probably too close to your current draw. Your wire size and lenght of run also enter into it. Check wire size tables for run length to make sure it is heavy enough. If wire size is 14 you can’t go over a 15 amp GFI so wire and GFI may be too light

The “cord” is underground from the dock to the house. At the house is where it plugs into the outlet. I don’t know the gauge underground but my hunch is that it’s 14. If I was doing it from scratch it would be larger. The run

The GFI outlet is 15amp. I guessed it was on a 15amp circuit so that’s what I bought instead of a 20amp outlet.

Pat K wrote:

. I need 120 feet of cord to reach the boat. With 14 gauge cords I was tripping the GFCI.

I do have a 12ga extension cord (50 or 100) and a 25ft 14ga. Did run extension cords direct to the house but I can’t remember if I used the big 12ga or smaller one that was handy. I’ll retry today with the heavy ga cords

carnivore wrote:

If 15 amp it is probably too close to your current draw.

How? The three 5a banks are 12v. That’s only 1.5a from the wall at 120v.

Do know those GFI sockets do wear out. I have replaced two or three at my house. One was used exclusively for charging my boat. Lost one in the kitchen as well. Maybe even the bathroom as well? I think maybe 4?

supercat wrote:

Does it trip other GFCI outlet say at your house in the garage or does it work there?

Runs fine in our detached garage on a short cord. That said the outlet is not a gfci. This is a shared multi-unit building so I can’t see where the wire goes back to from the outlet.

Reef W wrote:

<div class=”d4p-bbt-quote-title”>carnivore wrote:</div>
If 15 amp it is probably too close to your current draw.

How? The three 5a banks are 12v. That’s only 1.5a from the wall at 120v.

Actually the mk315d specs a 2.7 amp input which is well low of 15 amps even with voltage drops. You could try a 20 amp receptacle to see if its make a difference. The breaker is designed to protect the wire feeding the outlet so for safety reasons you are good. Page 4 of the manual says that extension cord for 150′ should be 12 awg. If the outlet or extension doesn’t work I there is a possibility that there is something leaking to ground in the charger. For some reason I remember I had a charger that would do this and I bought a 3-2 grounding wire plug that you would use in old house wiring and then it would not trip the gfci. I do not recommend this but if you have on laying around it would let you know it is the charger. Good luck!

Attachments:

1. 

   370-4287_P.jpg
   

1. Minn-Kota-Onboard-Digital-Chargers-Owners-Manual.pdf

If it is a 14 ga wire going to the GFCI only put a 15 amp GFCI outlet on it. 12 ga can have a 20 amp GFCI on it. Harbor freight had the best price on a 100’ 12 ga extension cord I could find a couple of weeks ago.

Rodwork wrote:

If it is a 14 ga wire going to the GFCI only put a 15 amp GFCI outlet on it. 12 ga can have a 20 amp GFCI on it. Harbor freight had the best price on a 100’ 12 ga extension cord I could find a couple of weeks ago.

There is no safety issue with putting a 20 amp gfci on a 14 awg wire since the breaker in the panel is fused at 15 amps which will trip if that load is greater then 15 amps. The electronics of the 20 gfci are more robust then the 15’s. Also I will suggest if you change your gfci to buy an upper brand “pass seymor” or something similar. Have seen cheap gfci internal electronics of these cheaper ones failing prematurely. Good Luck

I think that some of you are missing the difference between what a xx amp breaker does and what a GFCI does.

xx amp breaker is supposed to trip when there is more currant (amps) running through it than what it is rated for. That will happen when you are running something and drawing more current or when there is a direct short from the load (normally the black wire or red and other colors) to the white (neutral) or ground (green is ground the world around in electric).

GFCI will trip when the load passes current to ground (or neutral) at (I believe) less than 5 milliamps amps in about 1/40th of a second. That is 1,000th of 1 amp.

If possible it might help to move the gfci down to the lake and make the one on the home a non. GFCI’s can be fussy on circuits longer then 100′

First thing I would do is put the boat next to the GFI and try it. If it works it’s in the wire to the lake. Maybe frost cracked it in a place a 2. If it pops it’s the GFI or upstream of it.

supercat wrote:

If possible it might help to move the gfci down to the lake and make the one on the home a non. GFCI’s can be fussy on circuits longer then 100′

That’s an interesting idea that could work. At house about the only thing we plug in is the pellet grill. Would that be okay to an outdoor outlet if it wasn’t gfci?

All – the run to the dock is in the neighborhood of 120’ish feet. I paced it off around 30 yards in a straight line.

That’s an interesting idea that could work. At house about the only thing we plug in is the pellet grill. Would that be okay to an outdoor outlet if it wasn’t gfci?

All – the run to the dock is in the neighborhood of 120’ish feet. I paced it off around 30 yards in a straight line.
[/quote]

If the outlet is outdoor depending on the year your structure was built and your local codes would determine if a gfci was required. I’m not saying you can’t change it for now and replace it when you sell but that would be your decision. Personally I would not hesitate. As others have said if you take the boat out of the water and plug it into a different GFCI and it works it either the GFCI of the wire. Three suspects it could be:

#1 GFCI
#2 Charger
#3 Wire to dock

Hodag Hunter wrote:

First thing I would do is put the boat next to the GFI and try it. If it works it’s in the wire to the lake. Maybe frost cracked it in a place a 2. If it pops it’s the GFI or upstream of it.

I think he said he has ran other device off of the wire so I don’t believe it could be the wire.

All receptacles outdoors are to be GFCI protected.

gfi outlets go bad and get weak over time. try installing a new outlet

Just curious did you have any luck on a resolution?

I just fixed a fluorescent work light that was tripping the GFI occasionally. Took it apart and found the ground wire terminal (green) had an aluminum rivet to the case that was loose. Hammer and punch, backed up on a steel bar, smacked it once and it’s fixed. Don’t know if you can disassemble your charger, but it’s worth a look. Disconnect from power before disassembling.

supercat wrote:

Just curious did you have any luck on a resolution?

@supercat No, the saga continues. Got all ready to do the tests everybody suggested. Always do a baseline check. Damn thing worked without issue, go figure. The silver lining is my 12ga extension cord is 100ft. With a little monkeying around I can just reach the house outlet from the boat. Next time it fails that will be my first move.

If you buy a new GFCI, don’t get the cheapest one you can find. It will make no difference if it is 20 or 15 amp. I know cheap ones trip on my charger.