Is boat 12v "smooth" enough for a computer

[esarratt]

Any problems with weird, spikey energy in boats?

I was wondering if some form of protection, besides fuses, was necessary for non-marine electronics used aboard boats.

I use a Panasonic laptop for my charts (and everything else) and I don't want to fry my computer.

I will be using a 12v car adapter with the laptop and there will be at least two fuses in the circuit, 1 in the laptop adapter itself and another in the fuse box.

OR does the computer's own power box smooth out the voltage for the laptop?

Thanks!

[pdxsailordiver]

I never had a problem using a laptop and 12v adapter. I switched to a mini itx computer along with a led 12v tv/ monitor. The powersupply I use is:http://www.mini-box.com/M4-ATX?sc=8&category=981
I have been using this setup along with a ubiquity bullet and a WiFi router. I run the router off the 12v powersupply. Trouble free for 3 years.

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[smac999]

the boat batteries are the smother.


a bad alt or charger can cause a bit of waves. the laptop adapter will likely convert the voltage and take anything out anyways.


fuse isn't going to help a voltage spike.

[esarratt]

Thanks for the information. That helps.

[conachair]

Never had any problems with eBay dc/dc converters supplying 19v for a laptop on a liveaboard. Boat power isn't that spikey, the batteries even that out, it can just vary quite a bit.

[ramblinrod]

The laptop runs off its own battery. The 120 vac adapter, charges the battery. If the adapter has a monal output of 12 volts DC, you can plug it directly into the laptop. If you have excess EMI in your boat 12V system, you may need to clean it up.

[hamburking]

Your 12v power off the boat batteries should be very smooth. However, you might want to shut off/disconnect the computer before you turn ON something with a heavy power draw, or start the engine.

I run a flat panel TV and dvd player off 12v, and every time the bilge pump starts, the dvd player resets to the beginning of the movie.

[S/V Alchemy]

Originally Posted by hamburking

Your 12v power off the boat batteries should be very smooth. However, you might want to shut off/disconnect the computer before you turn ON something with a heavy power draw, or start the engine.

I run a flat panel TV and dvd player off 12v, and every time the bilge pump starts, the dvd player resets to the beginning of the movie.

The economical way to do this is with a DC/DC converter. The usual way is to have a "pure sine" inverter for running stuff with small motors. You can plug into AC then and just charge like you were at home. You want to even out the voltage spikes, as has been said, and drawing via inversion, while "lossy", does this. It's fine if you charge while motoring or at 1200h with solar panels, etc.

[KWISPEL]

I have there 2 on the boat.

- 1 model have a bar how I manual can move for diffrent voltages. Thise one do it al 3/4 good and well round the world.

- The seccond one switch to other voltages if i puch on a button how regulate a electronic regulator. One a day jump he to a other voltage. On the momment that i was removing the plug in the pc was he bussy to charge the battery. Result a smelly computer and after a reset was he farther again good working and stay he on his normal voltage.
On this way prefer i a manual swich for theregulation of the voltage but maybey had i bad luck

[SoonerSailor]

If you want to be safe install 15 volt avalanche diodes ( e.g. A Transorb) across the supply, with fusing on the supply side of the diodes. The internal resistance of the battery is usually too high to take out many serious spikes. OTOH you may be fine without any protection at all, but I like to play it safe myself.


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[Cheechako]

No, there are voltage spikes. Especially when you start your engine or the charger kicks in.

[hellosailor]

Many folks say the battery bank will eat any spikes. But equipment manufacturers keep saying there WILL be spike that WILL blow out gear if it is turned on. And at least one prime maker of LEDs have said an "automotive" starter will throw spikes up to 600V and a light truck starter up to 2000V. Just for a couple of milliseconds, but that's enough to fry their prime components if no protection is used.


You want to know for sure, on your boat? Hook up an oscilloscope, hit the starter a few times and see if the 12v system always stays at a dead flat 12V.


Or, just get in the habit of keeping all the electronics OFF when starting and stopping the engine.

[Paul Elliott]

If you have a separate starting battery then spikes won't be a big issue. I run my 12V boat computer directly from the house battery, and it works fine. Even running the electric windlass doesn't phase it.

But I've got big batteries and a nicely-wired system. It's always possible that a less-optimized wiring plan could exhibit problems.

If you are using a car-type adaptor for the computer than it should be OK. Having just the single battery, cars can have a spiky 12V, and the adaptors are designed to deal with this.

[Don1500]

I have been running my computers off the 12dc line for four years, no problem. I use an automotive 12VDC computer line (Looks just like the 120VAC line except it plugs into the 12VDC plug, in the car or on the boat.

[hamburking]

Originally Posted by S/V Alchemy

The economical way to do this is with a DC/DC converter. The usual way is to have a "pure sine" inverter for running stuff with small motors. You can plug into AC then and just charge like you were at home. You want to even out the voltage spikes, as has been said, and drawing via inversion, while "lossy", does this. It's fine if you charge while motoring or at 1200h with solar panels, etc.

"lossy" is right. You'll use 3 times the power with that setup, at least. If you aren't starting the engine, you will likely be fine. The battery in your laptop acts like a big capacitor, and dampens any mild spikes or dips.

Another solution might be to hard wire a 12v outlet to one battery, while the panel is run from another. If you have space for this extra battery, you would have a pretty nice, and very secure setup, without all the associated losses of DC to AC to DC conversion.

Yet another solution is to purchase a computer UPS - uninterrupted power supply. Its essentially a 12v battery in a box with charger and spike/surge suppression.

However, I think you might be overthinking this...I don't think there is a problem with your original setup.