Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 26-01-2015, 17:45   #16
Senior Cruiser
Wanderlust's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: NSW Central Coast
Boat: Lagoon 410
Posts: 499
Re: Two fried laptops later.

Originally Posted by Errantries View Post
We have a Cobra CPI 2575 that uses a modified sine wave ........... we are only getting 100 volts out of the outlet.
Laptops and other electronics can be sensitive to modified sine wave, let alone low voltage. We have 2 laptops aboard and the power supply for one buzzes and gets hot when running on the main inverter (modified sine wave).

I solved it by buying a small 150W sine wave inverter for electronics only.

Whatever the case, 100 volts suggests a faulty inverter.

Wanderlust is offline   Reply With Quote
Old 26-01-2015, 18:19   #17
Registered User
leftbrainstuff's Avatar

Join Date: May 2011
Location: San Francisco and Australia
Boat: Liberty 458
Posts: 1,978
Re: Two fried laptops later.

The fact you've had many electrical failures hints at a persistent but intermittent problem.

I'd suggest you have a qualified marine electrician help you out.

Otherwise log your AC feed and add or remove loads and devices until you find the culprit.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

leftbrainstuff is offline   Reply With Quote
Old 26-01-2015, 19:17   #18
Registered User
Steady Hand's Avatar

Join Date: Jul 2014
Location: Crewing All of 2017 Available Globally
Boat: OPB = Crewing in 2017
Posts: 4,851
Re: Two fried laptops later.

Originally Posted by leftbrainstuff View Post
The fact you've had many electrical failures hints at a persistent but intermittent problem.

I'd suggest you have a qualified marine electrician help you out.

Otherwise log your AC feed and add or remove loads and devices until you find the culprit.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app
That is what I was thinking too.

To the OP:

Thanks for providing the info on location and weather etc.

Though I am no electrical engineer this looks like a case where deduction is important.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." -- Sherlock Holmes
This topic interests me as I recently replaced my PC laptop (that died) with a Macbook Pro, and I would hate to lose my new mac (and iPad or other devices) to some kind of electrical gremlin on a boat.

Good luck.
Ahoy All Sailors! Need experienced crew for a passage or delivery in Atlantic, Pacific, Caribbean, Med, PNW, ICW, coastal or across an ocean anytime in 2017? I am available on 24hr notice. See my CF Profile "About Me" page for details. Happy to lend a hand!
Steady Hand is offline   Reply With Quote
Old 26-01-2015, 20:52   #19
Registered User

Join Date: Feb 2014
Posts: 14
Re: Two fried laptops later.

I'm leaning to the same. There's something in our electrical system that's causing spikes... we just need to figure out where they are coming from. The iPhone battery "exploded" in my SIL's words (after she had flown back home), but she left that thing plugged in all the time, like we all used to do before moving on a boat, I guess. Had it plugged in a USB outlet wired to the 12v DC system. The cords just stopped working after being plugged in the same outlets- hard to tell when that happened.

I did some research on the Cobra inverter, and I'm hearing that it's normal to get a slightly lower voltage reading from these devices than expected, so I'm hesitant to say that it's faulty.

I'm not really sure how to "see" when these spikes occur, as I'm not sure if my multimeter will detect them. I doubt that my multimeter is RMS capable. Will any multimeter do the trick for me, or do I need something fancy? To be honest, we are really only using the 110 inverter to charge our laptops. Every once in a while we'll use it for a sewing project, but that's it. No microwave, coffee maker, or other kitchen do-dads. Our power tools run on a different inverter running 220.

Anyone got a phone number for a solid marine electrician in Cartagena, Colombia? What about in Colon, Panama?

Right.... You guys are my Obi Wan. My only hope.

Thanks again for your input. I'll definitely report back on any findings. Feel free to keep throwing me a bone or two.
Errantries is offline   Reply With Quote
Old 26-01-2015, 21:16   #20
Registered User

Join Date: Aug 2007
Location: West Indies
Boat: Burger 74' motor yacht, 65 foot 12 metre, Flicka and sailing dinghy
Posts: 635
Two fried laptops later.

Is your surge protector really a surge protector or is it a mere power strip? Also it may not be any good if paired with a portable inverter such as the one you have. Surge protectors work by sending the voltage spike to the grounding wire and then to ground Your inverter is grounded to??
An MSW inverter will read lower voltage with most multimeters...your Cobra probably is putting out 110.
If you look at Apple forums you will see that MSW inverters tend to fry Apple products. I do not know why, but you are not alone.

Sent from an undisclosed location on the high seas or from the lounge chair by the pool, you decide.
To a hammer, everything looks like a nail.
dohenyboy is offline   Reply With Quote
Old 26-01-2015, 21:50   #21
Registered User
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,426
Re: Two fried laptops later.

YOu didn't explicitly say... so I am going to ask... are you in a marina? Are you plugged in?
zboss is offline   Reply With Quote
Old 26-01-2015, 21:54   #22
Registered User

Join Date: Aug 2012
Location: Cruising the Gulf of Mexico.
Boat: 1980 Morgan 415
Posts: 1,439
Re: Two fried laptops later.

While you should be able charge your laptops and run your equipment from your inverter, it sounds as if you are dealing with a problem that will be hard to fix on the Internet.

Harmonics issues involving inverters can do a lot of damage, including causing fires.

Looking for another pretty place to work on the boat.
Working on spending my children's inheritance.
Cap Erict3 is offline   Reply With Quote
Old 26-01-2015, 23:08   #23
Registered User
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,645
Re: Two fried laptops later.

Originally Posted by a64pilot View Post
...I'd say get a DC to DC convertor, a car charger to charge your laptops...
Me too.
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Old 27-01-2015, 00:04   #24
Registered User
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,019
Re: Two fried laptops later.

The reason you measure 100V out of the inverter is because it is a modified sinewave inverter. Unless you have a true RMS meter (most cheap meters are not true RMS) it will read low because the peak of the output is not 170V like a true sine wave. In fact, the inverter output isn't a sine wave at all. It's actually a type of pulse that goes positive, then to zero, then negative and repeats 60 times per second. (I assume you have a 60Hz inverter). If you are looking for spikes then look no further than your inverter. It makes fast rising pulses all the time. It's a shame that these companies get away with using the term modified sinewave when the output has no resemblance to a sine wave at all.

Surge suppressors from Home Depot will do nothing to help. In fact, they may make things worse. I would eliminate all that stuff.

I don't wish this to sound cruel but you have a 2,500W inverter that sells on Amazon for less than $200. It is not possible to build a high quality inverter at that price per watt. You might consider getting a much smaller inverter (say 600W) pure sine wave and try that. Defender sells the Go Power! GP-SW600 Power Inverter pure sine inverter priced at about $300 in the US. In Columbia I don't know what is available. If you find something there post the model here and we can check to see what its specifications are.
transmitterdan is online now   Reply With Quote
Old 27-01-2015, 00:45   #25
Registered User
the_alpine's Avatar

Join Date: Dec 2011
Location: st petersburg, fl
Boat: O'Day 302
Posts: 263
Re: Two fried laptops later.

Backing up a bit...

What EXACTLY do you mean by fried?

And how EXACTLY do you know?

Sent from my iPhone using Cruisers Sailing Forum
the_alpine is offline   Reply With Quote
Old 27-01-2015, 01:08   #26
Registered User

Join Date: Jul 2013
Location: San Diego, CA
Posts: 3,157
Re: Two fried laptops later.

If both laptops were plugged into the same power brick at the time they fried, then I would suspect the brick as the defective unit. If the MSW inverter were indeed screwing anything up, it would screw up the power brick.

I'd recommend a DC to DC converter to run any future MacBooks just for the sake of energy efficiency. It's slightly more efficient than converting 12vdc to 110vac then converting 110vac down to 19vdc or whatever Macs use.

If you're really serious about monitoring your AC voltage, they sell some data logging DMMs on Ebay for a reasonable price.
socaldmax is offline   Reply With Quote
Old 27-01-2015, 01:40   #27
Registered User
nimblemotors's Avatar

Join Date: Apr 2011
Location: Sacramento, California
Boat: Solar 40ft Cat :)
Posts: 1,557
Re: Two fried laptops later.

Originally Posted by Errantries View Post
We've also fried several iPod/iPhone charging cables (just won't work anymore) while charging DC straight from the battery, and my sister-in-law's iPhone battery fried also after charging from the DC side.
These failures have nothing to do with the inverter, whether sine wave, square wave, or a triceratops wiggle. They do sound like high humidity failures,
and perhaps that is the charging brick problem, and it has put out 110vac to the laptop instead of 18vdc, which would kill the laptop.
I would not test the charging brick with another laptop after it killed two already.
MiniMPPT Solar Controller
nimblemotors is offline   Reply With Quote
Old 27-01-2015, 05:07   #28
Bailing as fast as I can.
GILow's Avatar

Join Date: Sep 2008
Location: Adelaide, South Australia
Boat: Swanson 42
Posts: 3,585
Re: Two fried laptops later.

I read all this with interest as I recently fried my cordless drill charger on the boat.

I have a decent sine wave inverter, and it has run everything I have plugged into it so far, but the other day I had left the master switch off, I plugged in the drill charger, nothing happened, I went "doh!" and switched the master 12V switch on, at which point the inverter fired up and nuked the drill charger, with the classic fried capacitor smell I have grown to know if not love.

So, I have learned to make sure nothing is plugged into the inverter as it is switched on, perhaps this situation occurred to the OP?

Very funny Scotty, now beam down my clothes.
GILow is offline   Reply With Quote
Old 27-01-2015, 05:31   #29
Registered User

Join Date: Feb 2014
Posts: 14
Re: Two fried laptops later.

Hi folks,

Thanks for the advice... here's a few answers to you questions.

dohenyboy: We bought both a surge protector bar and a voltage regulator. The voltage regulator claims to keep the voltage in a certain spectrum, protecting against spikes. I'll have to take a look at how it detoured the voltage spikes and where the grounding is. This was just a temporary solution... not something that we thought we'd use permanently on the boat. Just a safeguard (we thought) while we find the reason for the voltage spikes.

zboss: We are anchored outside the marina. Not tied up and not plugged into shore power.

The_Alpine: We took both computers to the mac store here, they were opened up, and I was told that the motherboards were dead (on both) due to surges in voltage.

socaldmax: The laptops were damaged while using two different charging bricks. And (for better or worse), I tested the second charger with my buddy's computer (after the second laptop fried), and it's working just fine.

Yes, the DC to DC option is a good work around, and we have a few chargers like this on board. But, we are seeing electronics failures while plugged into both DC and the 110 AC inverter. I think, stupidly, when we saw electronics being damaged by our system, we thought using the 110 AC would be safer since the voltage from the battery was being converted through the inverter. I'm realizing now that this wasn't a good call. But, I'd like to get to the heart of the issue and make sure my system isn't killing all my electronics.

The options here regarding MSW versus PSW are similar to what I'm finding online. While the MSW are cheaper and a PSW is definitely better, I'm finding a lot out there that says the MSW shouldn't completely damage my logic board. Shouldn't is the key word I guess.

It's also possible that the DC charging problems could have a different root from the AC charging problems. Maybe the cords and the iPhone died due to overcharging or humidity, but the laptops died due to my MSW inverter. I can't kill anymore computers, so I'll start with getting a new inverter (we've got some guests coming soon that can bring it from the states), and we'll look for a marine electrician in Panama. We inherited the old inverter from the previous owner.

Another interesting thought I had last night... both laptops died in similar circumstances. They were being charged from the inverter, and while being plugged in, I had attempted to turn them on. With the first laptop, the battery was drained, so it was plugged in, left to charge a bit, then attempted to be turned on (but wouldn't). With the second laptop, some settings were changed and I needed to do a restart. Laptop was being charged from the inverter, it was powered down, but then wouldn't power back up. I wonder if the powering on is when the damaged occurred, or could it just be when you see the symptom present itself of logic board damage?

Thanks again gents.
Errantries is offline   Reply With Quote
Old 27-01-2015, 05:57   #30
Registered User

Join Date: Feb 2008
Posts: 2,061
Re: Two fried laptops later.

There is no way I can think of that a motherboard would fry without the charging brick also being fried. The brick does voltage conversion and isolation, but it is easily damaged by modified sine wave inverters. DC voltage coming from the brick is also further regulated on the main board. I'm with others who recommend a pure sine wave inverter for electrics.

You didn't specifically state the modes of computer failure. Condensing atmosphere, bad power, vibration or shock, and heat are the leading causes of computer failure. Were your computers sitting on top of charts or papers or fabric that might have blocked the bottom ventilation?

SailFastTri is offline   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fried Battery Question Canibul Electrical: Batteries, Generators & Solar 38 05-05-2014 22:02
Fried windlass? McGinnis Anchoring & Mooring 11 06-01-2013 07:03
Have I fried my M802 SSB? TabbyCat Marine Electronics 3 03-02-2012 20:32
Odyssey Batteries - Now, Two Years Later Journeyman Marine Electronics 0 20-02-2011 13:24
fried inverter with chips and sauce seafox Construction, Maintenance & Refit 6 11-04-2007 03:40

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 15:20.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.