Another crazy idea?

[Brian Degulis]

I've got a PC as a nav computor on the 60C. I'd like to be able to run it without having the gen set running. I don't want to install an inverter. I put a battery backup in when I installed the pc. The Battery backup uses 2 12V sealed batteries about the size of a motorcycle battery and it runs the PC and monitor for around 30 minutes or so. I'm thinking about getting 2 larger Sealed 12V batteries mounting them and either wiring them up with the existing batteries or replacing the existing batteries with the larger ones. This would probably get me 4 to 6 hours of run time on the PC.

Do you think I might have a problem with the backup charging the larger batteries?

Do you think I might run into problems running the back up on battery power for that long of a time period?

Brian

 

[GJH]

The back up is an inverter. Most can run indefinitely as long as there's juice, but it might be good to check with the mfr of your specific model. If your computer is happy with the quality of the power supply, go for it.

 

[MikeP]

Agree w/George...INVERTER! Just suck it up and buy the Outback 3232!

 

[REBrueckner]

I can't tell exactly what you are describing: a separate backup consisting of a battery charger and batteries? What are you trying to accomplish: run the pc when you are underway from a separate dc power source? It would be a shame not to tap into battery power aboard as you will constantly provide charge when navigating underway.

Either the included charger will burn up/overheat when a much larger set of batteries gets low (due to excessive output demand) or it will just take a long time to charge them all when power for charging is available.

Long periods on back up might drain the back up batteries to unacceptably low levels...meaning long charge times or short life due to excessive discharge.

Sounds like you can't tap into 12volt dc batteries aboard??? As in maybe you have all 32volt ??

Why not use a small inexpensive inverter sized just for the pc? I used a 60 watt inverter for years to power a 19" 120volt TV set...worked fine off 12v dc house power...this might not be easy if you have 32 volt power aboard, by any electronic store has inexpensive 12volt dc to 120 volt ac inverters....

 

[SKYCHENEY]

Brian,
Before I installed my inverter, I ran my nav PC with one of the cheapo inverters that you can plug into a cigarette lighter. If you don't have a cig lighter socket, get one and hook it up to one of the converters that is already powering your electronics.

Here is a 150 watt model for $30

http://www.pcconnection.com/IPA/Shop/Product/Detail.htm?sku=453397&SourceID=k232270

 

[Canuck Dennis]

That's all I use on the Hatteras, works great, beeps if the battery gets too low.

 

[Brian Degulis]

Brian,
Before I installed my inverter, I ran my nav PC with one of the cheapo inverters that you can plug into a cigarette lighter. If you don't have a cig lighter socket, get one and hook it up to one of the converters that is already powering your electronics.

Here is a 150 watt model for $30

http://www.pcconnection.com/IPA/Shop/Product/Detail.htm?sku=453397&SourceID=k232270

I thought of small inverter but I've had trouble in the past with modified sine wave running a computor. The other concern was would the existing 32V to 12V converter have enough zip to power it. I know the PC and LCD monitor require more that 150 Watts I think it's around 300 W.

Now you gave me another idea. The computor battery back up is an inverter that produces clean AC to run the PC. It runs on 24V 2 12V batteries in series. So what if took the batteries out of the battery back up and got a 32V to 24V converter and wired it directly to the back up?

Brian

 

[SKYCHENEY]

I thought of small inverter but I've had trouble in the past with modified sine wave running a computor. The other concern was would the existing 32V to 12V converter have enough zip to power it. I know the PC and LCD monitor require more that 150 Watts I think it's around 300 W.

Now you gave me another idea. The computor battery back up is an inverter that produces clean AC to run the PC. It runs on 24V 2 12V batteries in series. So what if took the batteries out of the battery back up and got a 32V to 24V converter and wired it directly to the back up?

Brian

I like that idea better than adding more batteries.

Most laptops run off of a 19v power supply, while most desktops with ATX power supplies are running 12vDC. It seems crazy to switch from DC to AC and then back to DC to run something, but it's still usually the easiest way to do it.

 

[saltshaker]

Sky beat me on that reply. The modified sine wave won't be an issue since the AC is converted to DC by your computer. You should get cleaner power from the inverter than your generator since the generator isn't crystal sync. Variations in voltage and frequency will greatly effect electronics, particularly monitors.

 

[Brian Degulis]

Actually I think the conversioin from AC to DC is what causes the problem with MSW. I've noticed that true sine wave runs chargers and MSW normally doesn't. The Outback inveter TSW on our MY runs everything including batt chargers. Our last boat had a MSW inverter and it would not run chargers.

Brian

 

[REBrueckner]

" So what if took the batteries out of the battery back up and got a 32V to 24V converter and wired it directly to the back up?"

No reason to remove the batteries. leave them in place....use for emergency back up....

 

[REBrueckner]

Although I am unsure exactly what your objective is, another alternative is one I used: Because my electronics on the flybridge would shut down when connected to start batts during main engine cranking, I ran a separate wire to the flybridge from my house battery bank. That enabled me to start all my electronics before getting underway from the house bank...maybe check courses,buoys,landmarks,etc.

Since I now had house and both start banks available on the flybridge, I added a switch so I could select the power source for my electronics....that way if my house bank failed while navigating I could slip a switch for backup power from a start bank....

Because I ran summers down east, from Nantucket to Maine, where fog is a always a concern, I considered my GPS plotter and radar "mission critical" components....on the other hand if your navigation is used in sunny climes for short runs more for convenience than need, backup power is not much of an issue.

 

[MicroKap]

Brian,
My 60 has an 8D mounted under the aft facing bench on the exterior of the flybridge and a battery charger mounted in the "cabinet" just to starboard of the flybridge door. There is a lot of room to mount batteries in boxes there with easy access for maintenance.

One question, what would be the purpose of being able to run without a generator? What about your refrig, air cond., etc.?

 

[Brian Degulis]

Just for short runs in the fall and spring when the air conditioning is not needed and the fridge can go off for a few hours. I hate running these 20KW gensets with no load.

Rob what I'm trying to do is come up with an in expensive simple way to run the PC for maybe 4-6 hours without the genset going. My original idea was basiclly just put much larger batts in the backup to acomplish that.

You guys as always got me thinking and that's good. Because I'm relizing my original idea is not so good. I've got a dedicated 12V batt for my electronics and the only charging source is a charger. So without the gen set going that batt would be getting depleted. I know DAA. Anyway what I think I'm going to do is get a 600W pure sine way inverter hook it up to the 12V supply in the pilot house to run the PC. And install a 12V alternator in the engine space to charge the electronics battery. Then I will no longer be generator dependant.

Thank for all the great replies!!!

Brian

 

[krush]

I've gotten many computer UPS (uninterpretable power supply) from trashcans because the batteries were shot. I just take out the battery, splice a longer wire, and hook it up to an old car battery or two LOL.

I'd just get a big ole deepcycle and hook it up to your UPS. When you are on shore or charging, the UPS will charge the battery...though it may take a while.

 

[Boatsb]

Just for short runs in the fall and spring when the air conditioning is not needed and the fridge can go off for a few hours. I hate running these 20KW gensets with no load.

Rob what I'm trying to do is come up with an in expensive simple way to run the PC for maybe 4-6 hours without the genset going. My original idea was basiclly just put much larger batts in the backup to acomplish that.

You guys as always got me thinking and that's good. Because I'm relizing my original idea is not so good. I've got a dedicated 12V batt for my electronics and the only charging source is a charger. So without the gen set going that batt would be getting depleted. I know DAA. Anyway what I think I'm going to do is get a 600W pure sine way inverter hook it up to the 12V supply in the pilot house to run the PC. And install a 12V alternator in the engine space to charge the electronics battery. Then I will no longer be generator dependant.

Thank for all the great replies!!!

Brian

Or put a 120V alternator/transformer to run the computer and other 120V items. A friend has a 5KW 120V alternator system on his boat and can run his house load while running with no generator.

 

[oldboat]

microcap,
how did you get that 160# battery up the ladder to the bridge?

 

[Brian Degulis]

Final Report Turns out I had a 32v to 12v converter already installed to power some stuff that is no longer on the boat. So I got a 600W pure sine wave inverter and wired it up to the converter. For some reason the Nobeltec program on the PC was shuting down when the GPS reciever antenna was turned on. This was only when running on the inverter. So I first I put a jumper in to connect the 32V ground to the 12V output on the DC to DC converter then another ground from there to the frame of the inverter and the PC. This solved the problem. I've had ground issues before with the nobeltec program and solved them the same way.

Brian