the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

Laptop Inverter Draining Car


Post ReplyPost New Topic
< Prev Topic Next Topic >
ezrollin 
Copper - Posts: 65
Copper spacespace
Joined: August 22, 2008
Location: Texas, United States
Posted: January 09, 2019 at 2:14 PM / IP Logged Link to Post Post Reply Quote ezrollin
I do not understand why laptops have such small batteries can run a very long time.
Yet once you plug in your laptop to your car through your inverter the car's battery instantly dies if its not running off the alternator.
It doesnt happen in 18 wheelers with 4 batteries but I'm sure it does drain it faster than even all the lights!
It feels like 12v power is just being thrown away, not efficiently being converted to 120v.
I've always believed that electronics hooked up but not on, dont have a power drain.
(like power supplies plugged into 120v but nothing connected)
This leads me to believe otherwise.
Thanks
geepherder 
Platinum - Posts: 3,584
Platinum spaceThis member consistently provides reliable informationspace
Joined: October 27, 2003
Posted: January 12, 2019 at 3:40 PM / IP Logged Link to Post Post Reply Quote geepherder
You could put an ammeter on the power lead to the inverter and see what the difference is with nothing plugged in and with the power supply.
My ex once told me I have a perfect face for radio.
i am an idiot 
Platinum - Posts: 13,334
Platinum spaceThis member consistently provides reliable informationspace
Joined: September 21, 2006
Location: Louisiana, United States
Posted: January 16, 2019 at 5:37 AM / IP Logged Link to Post Post Reply Quote i am an idiot
An inverter has a switching power supply. Even the small ones have at least an amp of current draw with no load.
ezrollin 
Copper - Posts: 65
Copper spacespace
Joined: August 22, 2008
Location: Texas, United States
Posted: January 16, 2019 at 7:10 AM / IP Logged Link to Post Post Reply Quote ezrollin
So what would that be? 1amp an hour draw? Batteries have like 800amps?
geepherder 
Platinum - Posts: 3,584
Platinum spaceThis member consistently provides reliable informationspace
Joined: October 27, 2003
Posted: January 16, 2019 at 11:48 AM / IP Logged Link to Post Post Reply Quote geepherder
One amp is a lot of draw for a vehicle that's just sitting. While your battery might be able to provide 800 amps at best, the amp-hour rating is much lower (maybe around 70). This will deplete a battery not in a matter of weeks, but days.
I don't even think most modern cars draw at tenth of an amp once the computers go to sleep (maybe 20-30 minutes after you shut off the engine).
The only way to know for sure how much current your power supply is pulling is to use an ammeter.
One other option would be to use a relay to supply power only when the ignition is on. Your laptop battery should hold up while it's not being used. Then when you get in and start up the car, it'll recharge the laptop.
My ex once told me I have a perfect face for radio.

If you wish to post a reply to this topic, you must first login.
If you are not already registered, you must first register.

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Sunday, June 13, 2021 • Copyright © 1999-2021 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer