Inverter "McGyver" Question

[Freestyle]

After 6 weeks in the Keys and Abacos some things are starting to break and unfortunately in the same system. My new generator has a leaking heat exchanger. Second hole of the trip after welding the first one earlier.

Now the inverter fried a cable and blew a hole around the post of one of the batteries which leaves me with no 110v power for the trip home. Not the worst problem but I would like to have running water (Galley Maid is dead and the 110v back up needs 110v).

I am considering disconnecting the inverter from its dedicated battery bank and attaching it to one of the 8D starter batteries using heavy duty jumper starter cables run abour 15 feet. I think this should allow the inverter to run onthe trip home keeping refrigeration and running water.

If this is a stupid idea for some reason (like some of my other posts) please let me know before I haul out of Green Turtle to FLL tomorrow.

Thanks

Bruce
Freestyle
1976 43 DCMY
Tampa

 

[brian4190]

be careful! when i installed my inverter i put a fuse between the battery and the inverter. as the cables are somewhat substantial i would suspect the fuse would blow before frying the power cable. if you dont know why your wire failed i would be very hesitant to connect the inverter directly to a battery without a fuse. if your inverter has a short in it your boat could go up in flames.

 

[(Nobody You Know)]

Don't hook the inverter up to anything.

See if you can find a cheapie 12V water pump to get you home on. If not, and if you have an aft water tank, by-pass the (110V) water pump and gravity will at least let you operate some systems.

Plan C: you can always flush toilets with a bucket of sea water, and probably buy just enough bottled water to get home on.

 

[garyd]

Hope your having a great time in the Bajammas mon.

That will not work. Do not do it! It might work for a very short while then catch on fire. Most inverters will pull well over 50 amps continuosly.

The best thing to do is replace the shot battery. I believe you could get a new battery at Marsh Harbor.

However make sure you understand why the first battery lost its post, else it may just happen again. If you know why it happen and it was not the inverters fault then replacing the battery is the best bet. Even if ya have to pay $100-$200 MORE for the same battery as over here might be worth the piece of mind.

If you wanted to wait until you got back to the keys you could pull into John Pennecamp and get a cab to worst marine and change it out there. For a buck or two you could even get someone to help pull the old then reinstall the new.

garyd

 

[Trojan]

I think you may find that the 15 feet of cable will be to long and lower your voltage raising the amps through the cables causing unwanted heat. You could try it and see. But watch for shorts. The burnt battery may have been from a bad connection and the jumper cables won't be any better. If you decide to use the jumpers don't leave them attached when not in use. The clamps on them are not very trustworthy and could cause a fire should it pop off under way.

BILL

 

[Pascal]

in short, yes it is a stupid idea since you don't know why the inverter "blew a hole and fried a cable"

if the cable fried, it must have gotten VERY hot. why ?

how big is the inverter, what were you running at the time, how far is the inverter from the battery bank, how big was the cable, why didn't you blow the DC fuse between the inverter and batteries ?

you either had a major malfuction in the inverter or the wiring wasn't up to standard. ex... a 3kw inverter needs 4/0 cables at 6 to 8'.. 4/0 is about 1" thick... if whoever installed the inverter went cheap... that's your problem.

running a long jumper cable is a receipe for disaster except maybe for a few minute jsut to take a shower ! jumper cables generate a lot of heat at the clamp and 15' is way longer than you should have bet batteries and inverter.

 

[Freestyle]

Thanks for the responses. I will just run without 110v power and get home.

I did try it this morning and it works but the benefit of running freshwater does not approach the risks stated. Thank you all for being such a great sounding board.

To answer some questions:

It is a Hart 2000 and is installed immediately next to the battery bank (6 golf cart) and has the right cables etc.

The battery cable and post fried when we lost shore power with a coffee maker, frying pan, microwave and who knows what else pulling juice. It fried a cable under the same circumstances a few years ago. I put changed the fuse size then so this must have been the mother electrical load.

The good news is that Don Hillman's will be on board Monday with a new heat exchanger for the generator which will make the trip around the Keys a lot more pleasant. I am pretty impressed on satellite phone call and I am back in business.

Thanks again and look for Freestyle if you are in Sout Florida, Keys and West Coast over the next week or so.

Bruce
Freestyle
1976 43 DCMY

 

[garyd]

If I was going to rate the dangers on a boat they would be:

1. Fumes from engines/generator.
2. 110v/220v shock hazard
3. Batteries either going to therma runaway or acid or heat etc etc
4. getting a fish hook in ya then infected
5. falling breaking something major blood loss (maybe a ways from help)
6. drowning while doing something stupid
7. sinking then exposure to the elements then death.

I would bet if ya could take all the data bases and query them they would closely match this list for pleasure boaters.

Since your really dealing with an inverter/battery your dealing with #'s 2 and 3 on the list. And the last time I checked attorneys were not good electricians LOL. So as the man says be careful out there.

P.S. post some pics.....

garyd

 

[34Hatt]

I would check into that fuse size it should blow before it melts a cable!!!!
That is why it is there, it could be a bad connection also was it between the battery and the fuse???

 

[krush]

If you only run a small 120v pump of the inverter it won't but a little bit of current from the batteries and you could use your jumper cable setup.

Very small load = very little current flow.


This is assuming your inverter isn't FUBAR'd and has a dead short in it.

 

[Freestyle]

Quote: And the last time I checked attorneys were not good electricians LOL

I was an engineer and Navy officer before becoming a lawyer. But many say my engineering skills drove me to law. The Navy wasn't ever going to give me a ship so I bought one and unlike the Navy, it seems to have an unlimited service committment.

Bruce

Freestyle
1976 43 DCMY
Tampa

 

[garyd]

An engineer lawyer. Well that explains a lot LOL. Hey on your way back if ya have time stop in the BYC would love to meet you and the family in person. We were scheduled to go to Bajammas mon but when they closed the big O...

Did not have a back up plan to get across to the Bahamas. So next year we have plan A and plan B. Anyway would love to pick your brain. NOT ON THE CLOCK, lol.

garyd

 

[spartonboat1]

If you are near civilization and a Radio Shack or equiv is nearby, then a small portable inverter might get you by for very small 120v loads.

I wonder if the battery went bad. I was charging 8D's and had a cell go bad. Battery was merrily boiling away and was plently hot. Lucky didn't fry anything.

You mentioned what units were on-line when it went bad. FWIW, I have a Freedom 2000 (Heart) with the control panel. The number of units on-line mentioned are very close, if not over the capacity of your inverter. That inverter has a spike capacity, so it can put out more than the rated capacity in bursts. But makes me wonder if a poor connection is at the battery terminal. High resistance= "that's hot" (Paris Hilton), coupled with the heavy load, equals "that's really hot" (Paris in the slammer).

I can't remember if I have observed first hand a direct short across battery terminals, but the amps will shortly emulate a good arc welder and melt down the terminals and metal parts in contact with them carrying the current. So a charged battery has the juice to generate metal melting heat.

enuf of my comments...

 

[SKYCHENEY]

Chances are that this was just a loose connection at the battery. It worked fine under normal conditions and then heated up when a larger load was put on it. It probably did not exceed the limits of the inverter or the fuse. It was just a loose connection and that is why it melted the post.

Once you replace the battery, it will probably be fine. But, just to be sure, check the fuse and keep an eye on it after you get it going again. Try putting a load on it and feel the cable to make sure it isn't getting too hot. I melted a terminal post a couple of years ago on the mains. It was just a loose terminal and it only took one touch of the start button to do it.

 

[ThirdHatt]

Freestyle, I am just south of Green Turtle on Guana Cay! Surely you have made it to Nippers while cruising the out-islands of the Abaco's, right? I'll be here for another week or so and I'll be on the lookout for Freestyle. We'll probably head over to Treasure tomorrow and Green Turtle Sunday or Monday.

There is an excellent mechanic just south of me on Man O War cay that happens to have been the main mechanic on my '72 58YF SINCE NEW! He knows these old boats well and works out of Man O War marina.

GOOD LUCK and have a safe trip home.

 

[doc g]

The positive terminal should be fused at the terminal,rating depends on size of the cable/inverter. Probably a loose connection as (Sky)previously mentioned, if this is not a new install......Pat