• Announcements

    • Zapata

      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  

Archived

This topic is now archived and is closed to further replies.

eclipsemullet

Laptop on car charger

Recommended Posts

I am running Expedition on a MacBook Pro under Bootcamp.

 

When I power the MacBook with a car charger into the boat's electric panel, it seems to drain the boat's battery rather quickly. It drops from 12.6v to 10.0v in an hour or so.

 

Is this to be expected or is there something wrong with our batteries?

Share this post


Link to post
Share on other sites

10V....! Sounds like your battery is dead. Read up online on "12V battery state of charge", but in short your 12V battery should be somewhere between 12.2-12.7V (50-100% charged) at rest. Will be a bit different under load, but it should never read at 12V or below (<50% charged or less is not good for lead-acid batteries), and certainly not 10V especially after such a short load. Time to replace the batteries iMO...

 

Also, an external laptop battery might be a good add-on if you specifically want power for your MacBook.

Share this post


Link to post
Share on other sites

Temperature: 67 degrees Fahrenheit

Percent Charge Unloaded Voltage

100 12.61

75 12.28

50 11.98

25 11.74

0 11.62

 

 

You should not run your battery below 50% charge so not below about 12 volts as has been said. If you have a fairly standard series 27 batter with about 100 amp hours and if you charger is drawing even 120 amps, which is likely is not, that would be 10 amps and you should get 5 hours down to 12 volts.

 

New battery time, they are dead.

 

Allen

Share this post


Link to post
Share on other sites

Temperature: 67 degrees Fahrenheit

Percent Charge Unloaded Voltage

100 12.61

75 12.28

50 11.98

25 11.74

0 11.62

 

 

You should not run your battery below 50% charge so not below about 12 volts as has been said. If you have a fairly standard series 27 batter with about 100 amp hours and if you charger is drawing even 120 ampswatts, which is likely is not, that would be 10 amps and you should get 5 hours down to 12 volts.

 

New battery time, they are dead.

 

Allen

Corrected above.

 

I think MacBook Pro charger pulls 85W (you should check), so certainly eclipsemuppet should get 5+ hours plus internal battery life if his battery capacity is >100Ah. Agree with Allen.

Share this post


Link to post
Share on other sites

 

Temperature: 67 degrees Fahrenheit

Percent Charge Unloaded Voltage

100 12.61

75 12.28

50 11.98

25 11.74

0 11.62

 

 

You should not run your battery below 50% charge so not below about 12 volts as has been said. If you have a fairly standard series 27 batter with about 100 amp hours and if you charger is drawing even 120 ampswatts, which is likely is not, that would be 10 amps and you should get 5 hours down to 12 volts.

 

New battery time, they are dead.

 

Allen

Corrected above.

 

I think MacBook Pro charger pulls 85W (you should check), so certainly eclipsemuppet should get 5+ hours plus internal battery life if his battery capacity is >100Ah. Agree with Allen.

Good correction!

Share this post


Link to post
Share on other sites