Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 07-12-2017, 10:01 PM   #11
sir_pudding
Wielder of Smart Pants
 
sir_pudding's Avatar
 
Join Date: Aug 2004
Location: Ventura CA
Default Re: [VE] Minimum battery capacity for internal combustion engine?

Quote:
Originally Posted by Johnny1A.2 View Post
That, and also to let you run lights, radio, whatever, for a while without the engine.
Since accessories are negligible power in that system, how long you can run them without the power plant seems to be below the resolution.
sir_pudding is offline   Reply With Quote
Old 07-13-2017, 06:21 AM   #12
The Colonel
 
The Colonel's Avatar
 
Join Date: Jul 2006
Default Re: [VE] Minimum battery capacity for internal combustion engine?

As I understand it, the amount of power used to cycle a starter motor is pretty low - it's all about getting enough voltage to turn the motor over and that only uses a tiny part of your battery capacity.
The Colonel is offline   Reply With Quote
Old 07-13-2017, 11:45 AM   #13
LokRobster
 
LokRobster's Avatar
 
Join Date: Mar 2005
Location: Republic of Texas; FOS
Default Re: [VE] Minimum battery capacity for internal combustion engine?

Ignition system is included in the ICE power plant weight/size/cost. So sure, you could save 10lbs and 1cf by removing the battery and starting the engine remotely like a race car :)

Definitely a system inside the granularity of Vehicles.
__________________
Our decades-old & rarely updated CarWars blog & Hotwheel conversion tutorial: North Texas Autoduel Association
LokRobster is offline   Reply With Quote
Old 07-13-2017, 01:03 PM   #14
Anaraxes
 
Join Date: Sep 2007
Default Re: [VE] Minimum battery capacity for internal combustion engine?

Checking a few specs for current-day real-world starter motors, it seems they're usually around 1% of the ICE's rated max power. (The largest ones Mitsubishi Electric makes are 7 kW, and that includes their lines for 24v starters for buses and large trucks; 5.5 kW max in the 12v lineup. Typical values for smaller passenger cars in the compact / midsize range around around 1.4 - 1.6 kW.)

Starting generally takes under 5 seconds even for a diesel or high-compression engine, so the fuel use to recharge the battery is the equivalent of less than ten seconds of idle operation. (Of the ICE, that is; not all of that power is going into the alternator to recharge your battery, so I'm not saying your battery can be recharged in ten seconds flat.)

The numbers seem small enough that I'd be willing to count it as just another piece that's already included in the ICE component. But it might be handy to have a ballpark figure for a rule-of-thumb in case someone needs to repurpose that piece or jury-rig something.
Anaraxes is offline   Reply With Quote
Old 07-13-2017, 01:30 PM   #15
Flyndaran
Untagged
 
Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
Default Re: [VE] Minimum battery capacity for internal combustion engine?

Quote:
Originally Posted by LokRobster View Post
Ignition system is included in the ICE power plant weight/size/cost. So sure, you could save 10lbs and 1cf by removing the battery and starting the engine remotely like a race car :)

Definitely a system inside the granularity of Vehicles.
I wouldn't go that far, because Gurps settings could easily involve after factory modifications like say finding a TL 9 battery and deciding to put it in your car.

As it is switching from uber common lead acid car battery to lithium ion could save weight that may matter when outrunning that lava flow, zombie cheetah, etc.
But I agree that for most games, batteries are below the resolution of player concern.
__________________
Beware, poor communication skills. No offense intended. If offended, it just means that I failed my writing skill check.
Flyndaran is offline   Reply With Quote
Reply

Tags
automobile, battery, car, energy bank, vehicles

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:58 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.