Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

I am considering keeping a jump starter portable external battery  in the car.  I am wondering if this battery could be used, when connected to the car electrical system through the cigarette lighter socket, to power the car electrical system to allow me to drive back home in case the alternator fails and the car battery is low.  Vendors claim that the car could even be started using the external battery connected through the cigarette lighter socket.

 

Is there any risk of damaging any car electrical system components doing this?

 

Thanks

Share this post


Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

4 hours ago, Philip54 said:

I am considering keeping a jump starter portable external battery  in the car.  I am wondering if this battery could be used, when connected to the car electrical system through the cigarette lighter socket, to power the car electrical system to allow me to drive back home in case the alternator fails and the car battery is low.  Vendors claim that the car could even be started using the external battery connected through the cigarette lighter socket.

 

Is there any risk of damaging any car electrical system components doing this?

 

Thanks

 

Absolutely no way.  The cigaret lighter socket is connected to the electrical system by a relatively light gauge wire, your starting battery used cables many times heavier to deal with the tremendous amperage draw that occurs during starts; if you tried to pull that kind of amperage through the lighter, you would instantly destroy your dash wiring harness and probably burn the car to the ground.  VERY bad idea............

Share this post


Link to post
Share on other sites

Thanks for your reply.  The vendor I was referring to sells jumper cables that include a fuse that are used to charge the car battery for 10 minutes.  According to the vendor the car can then be started using the car battery.  The vendor does not recommend to start the car directly from the back-up battery.  In any case, my question was more related to being able to drive back home, if the alternator fails and the car battery is low, using a back-up battery connected through the cigarette lighter (with minimal electrical load, just the lights, if it is night).  Does that seem possible?  What would be a fuse size that would ensure sufficient protection?  I assume that the car has its own fuse to protect the cigarette lighter cable.  Is that correct?

 

Thanks

Share this post


Link to post
Share on other sites

Yes, there's a 15 amp fuse protecting the cigarette lighter. In the event of alternator failure, it's likely your car will need more than 15A of current to power its engine, DME, headlights, etc.

 

If your battery is healthy, it should last you some miles. A healthy battery should have tens of Ah reserved capacity.

Share this post


Link to post
Share on other sites

Thanks, Ahsai.  I guess the back-up battery could still be used to travel a little further, if necessary, if its use does not cause any issues. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Content

    • By Richard in Alberta
      Greetings - I have traced a coolant leak to the rear of the alternator - wondering  if anyone else has seen this and whether its repairable or I just have to commit to replacing it (once I can find a replacement - they seem to be rather hard to find at the moment).... Cheers.
    • By Silver_TT
      2002 Carrera 4S. I did a search and didn't see these exact symptoms simultaneously.
      See attached picture. I was driving at 5k RPM in 3rd when the power of the car was suddenly reduced (by the computer I believe) and the console beeped displaying the following 4 checks: 1. Brake distribution 2. PSM failure 3. ABS failure 4. Battery -- also, as you can see in the pic, the battery voltage meter is maxing out. When I disengage the clutch from the engine the voltage drops some (and the brake/ PSM/ ABS messages go away and are temporarily ok) but is still running significantly higher than what I'm used to seeing. Could this high voltage be damaging to the electronics system? Presumably there's something going on with the voltage regulator. Does the ABS/ PSM turn off automatically for saftey when there are voltage spikes?
      My battery is an Interstate and is ~ 1yr old. This seems to me like the alternator (possibly the voltage regulator). I realize it would be better if I had a Durametric to hook it up to and get the exact error codes off of. That may need to be done to properly diagnose what's going on here.
      Thanks in advance for any help/input.
      Cheers,
      Alex

    • By Mark Stubbs
      Hi guys.Finnally got the Boxster on the road after an enforced year stood.It sounded a bit rattly when I started it up.I have done about 50 miles in it since all short journeys, and it still making the same noise.Not knowing much about these engines not sure if it's something more serious than tapped, alternator bearing???.Im not driving it and will get it recovered to an Indy for assessment, so any suggestions will be gratefully received. Hopefully other club members will chime in.
    • By rting
      (60,000km on the odometer) Now the car is completely dead with no Interior lights anywhere.  Car was sitting there with a charger on timer charging for maybe an hour per day for a month while I was on vacation.  The CD/radio was making a clicking sound prior to and I thought the battery needs a boost to start after a month.  Now nothing!

      Well almost nothing - behind the dash board there is some very weak clicking/sound.

      Thought I ask here first - before towing it to the Porsche dealership. ?
    • By Anthonygallimore
      I just recently put a new battery in my 2000 Porsche Boxster and now my radio is requesting a 4 digit code. It is a cdr 220 radio, Becker 1. Type 4462. And the serial number is y5043037. Please HELP if anyone knows how to remedy this. Thank you!
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.