Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

> need an Electrical engineer to explain this, jump box
r_towle
post Feb 8 2023, 06:31 PM
Post #1


Custom Member
***************

Group: Members
Posts: 24,573
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



Hi,
I have a 997 (this feels like the start of a support group thing)

This car has an electric front hood latch.
So, the battery needs to be hooked up to open the front hood where the battery is...
Its not logical, but Porsche put in a shortcut.

So, go to the fuse box inside, pull out a red lead, and hook up a 12VDC battery to this lead, and chassis ground...
Hood opens.

Instead of using a full size heavy car battery, I went and bought a lithium battery "jump box" thing
Schumacher SL1639 Lithium Portable Power Pack and 1000A 12V Jump Starter

So, it will not work.
We ended up getting a full size battery, with jumpers, just to open the hood, so we could reconnect the battery.

My question is...WHY does it not work?
When I put my meter on it, I see 16VDC
ITs fully charged.
Its on.

The Tech support told me the unit can only be used for jump starting a car.
The mechanic at the shop told me he also had this issue, and the unit needs to see a load??

I will return this if it will never work...but I really need to know why it won't work.
I can get a motorcycle battery, or some other unit that will take care of my needs...but this thing should work...yet it does not.

Anyone care to explain electricity to me?

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
mepstein
post Feb 10 2023, 07:59 AM
Post #2


914-6 GT in waiting
***************

Group: Members
Posts: 19,255
Joined: 19-September 09
From: Landenberg, PA/Wilmington, DE
Member No.: 10,825
Region Association: MidAtlantic Region



These will fit in the palm of your hand and start a large truck with a dead battery. I’ve personally used it on the truck. It’s what I purchased for my daughter. Gets high reviews.


Attached thumbnail(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
fixer34
post Feb 10 2023, 05:03 PM
Post #3


Senior Member
***

Group: Members
Posts: 1,080
Joined: 16-September 14
From: Chicago area
Member No.: 17,908
Region Association: Upper MidWest



QUOTE(mepstein @ Feb 10 2023, 07:59 AM) *

These will fit in the palm of your hand and start a large truck with a dead battery. I’ve personally used it on the truck. It’s what I purchased for my daughter. Gets high reviews.

Sorry, there is no way in hell that unit will provide 1000amps unless you measure the time in milliseconds. The clamps themselves would melt after 2-3 seconds.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Superhawk996
post Feb 10 2023, 05:22 PM
Post #4


914 Guru
*****

Group: Members
Posts: 5,779
Joined: 25-August 18
From: Woods of N. Idaho
Member No.: 22,428
Region Association: Galt's Gulch



QUOTE(fixer34 @ Feb 10 2023, 06:03 PM) *

QUOTE(mepstein @ Feb 10 2023, 07:59 AM) *

These will fit in the palm of your hand and start a large truck with a dead battery. I’ve personally used it on the truck. It’s what I purchased for my daughter. Gets high reviews.

Sorry, there is no way in hell that unit will provide 1000amps unless you measure the time in milliseconds. The clamps themselves would melt after 2-3 seconds.

Agree on the 1000A rating - marketing hype.

Ratings are like cheap stereo ratings of old - optimistic and rated at peak.

However, research how lithium ion batteries perform. They can be designed for peak energy or peak power. A single 18650 cell can deliver 30A in short repetitive bursts. Pouch cells can put out even more current due to large surface area of the anode and cathode. This ability to deliver very high power out of such a small package is what makes Lithium ion batteries dangerous if used improperly and/or short circuited.

It is VERY EASY for these small jump packs to crank a completely dead vehicle (with or without vehicle battery) with a very small footprint and light weight. Used to use them a couple times a week. Way better than hauling around those old lead acid jump packs.
User is online!Profile CardPM
Go to the top of the page
+Quote Post

Posts in this topic
r_towle   need an Electrical engineer to explain this   Feb 8 2023, 06:31 PM
mgphoto   2 words Ohms Law.   Feb 8 2023, 07:09 PM
worn   2 words Ohms Law. I raise you with ROYGBIV. I g...   Feb 8 2023, 07:22 PM
r_towle   Sorry….I read ohms law and I don’t get why thi...   Feb 8 2023, 07:36 PM
914GT   Do you see 16v with it attached to the load? I su...   Feb 8 2023, 07:38 PM
r_towle   Do you see 16v with it attached to the load? I s...   Feb 8 2023, 07:48 PM
76-914   Rich, buy a 12v cordless drill battery or 8 flashl...   Feb 8 2023, 07:43 PM
r_towle   Rich, buy a 12v cordless drill battery or 8 flash...   Feb 8 2023, 07:47 PM
mepstein   The jump packs are really great in the usual situa...   Feb 8 2023, 08:04 PM
StarBear   The jump packs are really great in the usual situ...   Feb 9 2023, 07:35 AM
r_towle   I have larger jump packs.. I wanted something lig...   Feb 8 2023, 08:37 PM
bkrantz   Not sure about 997s, but my 991 has a hidden pull ...   Feb 8 2023, 09:00 PM
r_towle   Yes we found and tested that pull. Can you imagine...   Feb 8 2023, 10:38 PM
bzettner   Yes we found and tested that pull. Can you imagin...   Feb 9 2023, 08:15 AM
87m491   Yes we found and tested that pull. Can you imagin...   Feb 9 2023, 02:09 PM
theer   Rich- I had the same thing happen to a friend’s ...   Feb 9 2023, 12:28 AM
Superhawk996   Maybe the little lithium ones have some kind of s...   Feb 9 2023, 08:03 AM
jd74914   Maybe the little lithium ones have some kind of ...   Feb 9 2023, 01:23 PM
Geezer914   12V alarm battery or 12V lawnmower battery.   Feb 9 2023, 07:00 AM
Front yard mechanic   My cheap hf battery charger has a chip in it it ha...   Feb 9 2023, 07:44 AM
GregAmy   My cheap hf battery charger has a chip in it it h...   Feb 9 2023, 07:48 AM
fixer34   I've been around electricity and electronics e...   Feb 9 2023, 07:26 PM
r_towle   Yah…I may go order a Milwaukee power access thin...   Feb 9 2023, 07:34 PM
targa72e   I will just echo what others have said. The device...   Feb 10 2023, 12:21 AM
GregAmy   Of course, why in the hell Porsche put the battery...   Feb 10 2023, 07:48 AM
mepstein   These will fit in the palm of your hand and start ...   Feb 10 2023, 07:59 AM
fixer34   These will fit in the palm of your hand and start...   Feb 10 2023, 05:03 PM
Superhawk996   These will fit in the palm of your hand and star...   Feb 10 2023, 05:22 PM
r_towle   Funny timing I left the trailer hooked up which ki...   Feb 10 2023, 05:51 PM
Superhawk996   Funny timing I left the trailer hooked up which k...   Feb 11 2023, 08:51 AM
r_towle   It’s cute, but I’m returning it because it doe...   Feb 11 2023, 03:17 PM


Reply to this topicStart new topic
3 User(s) are reading this topic (3 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 5th May 2024 - 04:29 PM