Two fried laptops later.

[Maine Sail]

Originally Posted by transmitterdan

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.

I have had a few customers cook rechargeable batteries with cheap MSW inverters. I fried some expensive DeWalt batteries using a customers MSW inverter and the green charge light stayed on for over 6 hours when it normally lasted less than 45. I got busy and never noticed.. Batteries were junk...

On some Li and NiCd battery chargers they simply don't stop when they should when fed a poor inverter power. Some MSW's are far better than others but pure sine has come way down in price. That said it could be moisture too...

[transmitterdan]

I failed to mention that it is entirely possible that the inverter is the root cause of all your electronic problems. The inverter can cause spikes on the 12V side too. So if you are having problems with 12V devices too the first thing I would do is get rid of that inverter.

Also, no matter what inverter you have it is a good idea to connect it directly to the battery bank through a properly sized fuse. Most manuals that come with inverters say that but some installers ignore the manual. With inverters you should read the installation instructions and follow them. It will help in preventing inverter induced problems with other 12V devices in the boat.

[Captain Bill]

If the bricks aren't fried I don't see how the motherboards could be fried from a voltage spike from your charging system. It would seem to have to come from induced voltage. Do you by any chance have an SSB or HAM radio and if you do is your charging station anywhere near your radio, or antenna system?

[the_alpine]

Strange indeed. Did you have AppleCare?


Sent from my iPad using Cruisers Sailing Forum

[travellerw]

Just an FYI.. Power spikes can come down different connectors and fry the logic board. Ethernet, USB, Display port are all possible paths for a spike.

This is the reason I asked earlier what other things were plugged into the laptop.

Another question I have. You mentioned an Iphone being fried. Was it plugged into a 110V charger attached to the Inverter, or was it plugged into a cigarette charger?

[Cap Erict3]

Originally Posted by Errantries

Hi folks,



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

If you own a meter, check for continuity between your neutral, AC ground, and your DC negative.

They need be isolated from each other in a marine environment.

These words are not from an Internet search or 2 day class but from decades of dealing with this stuff hands on.


Looking for another pretty place to work on the boat.

[George DuBose]

The second laptop came from the dry, winter climate of Michigan, and was only here in the Caribbean for 12 hours before it fried.

Dry, COLD, winter climate of Michigan, flying in the cabin or the cargo hold? Arriving on a nice warm Carribean island, sounds like a condensation recipe...

My Macs either run from the batteries via a 12v cigarette lighter socket (these need a new name) or directly from shore power.

One shouldn't have these same problems connecting to the ship's batteries?

[darylat8750]

I had some dock mates in Mexico lose computers from ac voltage sag. The voltage at the end of the dock was sometimes under 95 volts. The theory was that the voltage got low enough that the currant went up enough to over heat the "power board ". (?).

[socaldmax]

Like Maine Sail said, not all MSW inverters are the same. If this is really a Cobra inverter, I'd swap it out for a good quality Pure Sine Wave inverter, since they are more affordable these days. I've personally had good luck with MSW inverters, but that doesn't help anyone else out.

If I were in the market for an inverter today, I'd get a PSW one.

I always recommend keeping an open mind when troubleshooting (especially electronics) so...

can you think of any major DC loads that might have come on at the same time: anchor windlass, 12v compressor, etc? These can cause spikes. Don't forget to investigate USB or ethernet possibilities.

[kudukuguam]

Two questioins: 1) What type of solar power controller are you using? I use 50 watt panels because they max out at about 17 volts so I don't worry about overvoltage or cooking my batteries.
2) Have you considered purchasing a voltmeter that has a "hold" function on it? There are lots that are available in the $ 20 range and "holds" the highest voltage it sees (don't forget, the AC display value on these cheap meters is an RMS (kinda like an average) so you have to divide the display by 0.707 for the max value)


Just a couple of suggestions.

[Old Swampy]

Square wave and modified square wave inverters deliver some pretty nasty wave forms as far as computers are concerned. We charge our phones and computers with devices that plug into 12 volt cigar lighter type receptacles, and we don't charge when the engine is running.

[colemj]

Originally Posted by Old Swampy

We charge our phones and computers with devices that plug into 12 volt cigar lighter type receptacles, and we don't charge when the engine is running.

Why not when the engine is running? That is the way they work in automobiles. Even at 14.8V, these are DC-DC converters that will have no problem here.

Mark

[kentobin]

Maybe I missed it but the Apple power brick was undamaged? If the brick appears ok but the computer was damaged there might be an issue with the brick. Seems odd the Kindle was not damaged and the Apple was.

Assuming the Apple brick appears good you might want to purchase a different aftermarket brick for your Apple not made by Apple. No idea if you can get anything except cheap Chinese garbage but it's worth a look.

I've been using an 8 year old Xantrex modified sine wave generator for years with Lenovo and LG electronics and haven't had a problem.

I've been reading the modified sine wave blogs for years and some people say they have issues with them and others do not with no real consensus. On the other hand aside from GILow 's comment I can't ever remember reading a blog with a complaint about a pure sine wave converter except for comments about the higher cost.

[irwin37]

"AC display value on these cheap meters is an RMS (kinda like an average) "


The way I have read that I think its backwards. Cheap meter use a average rather than RMS, A good RMS meter is not cheep. House-hold RMS voltage is around 120 vac were peek is around 170 vac.

Still dont think we are getting to the problem yet.. Any chance you had a near lightning strike, and now the damage is showing up one by one.

I had a near strike a over two years ago and the tuner in my tv progressively got worse over time... like one year of time so damage can be hidden for some time then suddenly go when stressed a little more than normal.

[socaldmax]

Originally Posted by kudukuguam

Two questioins: 1) What type of solar power controller are you using? I use 50 watt panels because they max out at about 17 volts so I don't worry about overvoltage or cooking my batteries.
2) Have you considered purchasing a voltmeter that has a "hold" function on it? There are lots that are available in the $ 20 range and "holds" the highest voltage it sees (don't forget, the AC display value on these cheap meters is an RMS (kinda like an average) so you have to divide the display by 0.707 for the max value)


Just a couple of suggestions.

Please tell me you are using an MPPT solar controller to control the charge to your batteries. Your solar panel output voltage should have no bearing on charge voltage, provided they can provide enough voltage to the controller to charge the batteries.

Some controllers can take up to 150v solar input, which allows one to run thinner cable with less voltage drop.


IRT cheap DMMs; true RMS DMMs will display the correct voltage, cheap non-RMS meters will display a low voltage and you must divide by .707 to get the correct V. The way you worded it makes it sound like RMS meters are the cheap ones.