Voltage drop? - Motorhome Forums, Motorhome Discussion, Motorhome Chat

User Tag List

 12Likes
Reply
 
LinkBack Thread Tools
post #1 of 16 (permalink) Old 21-09-2019, 17:13 Thread Starter
Senior Member
 
barryd's Avatar
 
Join Date: May 2008
Location: Richmond North Yorkshire or up an Alp. I like Guitar, Beer and flying around France on a Scooter
My Motorhome: A big White one.
Posts: 27,575
Thanks: 307
Thanked 1,016 Times in 881 Posts
Personal Aire
Voltage drop?

Back on our second trip of the summer and in the three weeks we were back I made some changes to the internal electrics. I put in a new four bank of 12v sockets for low ampage stuff and I bought a 5m heavy duty 12v extension cable. I bought that as I didn't have the time or the skills to fit proper extra 12v sockets around the van. I thought if I plugged it into the original 12v outlet In the TV cupboard it would run anywhere inside the van to use a laptop or phone etc and it would also power the 12v ring pump for blowing up tyres outside.

Anyway I plugged it in and tried the pump. It chugged for a few seconds then died. Took out the extension and plugged the pump straight into the socket and it was fine.

I am now reluctant to try it with the 12v laptop charger and my laptop as if it's not providing enough voltage it could knacker it. I'm using it now though to charge my phone which is a bigUn and it's charging fine.

Any thoughts?
barryd is online now  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 21-09-2019, 18:06
Senior Member
 
erneboy's Avatar
 
Join Date: Feb 2007
Location: Spain + Germany
My Motorhome: Four Winds RV
Posts: 27,041
Thanks: 164
Thanked 475 Times in 447 Posts
The pump will be a big draw compared to the laptop. Have a read of the info on it. Mostly with pumps it's best to connect direct to the battery.

Propaganda works best when those who are being manipulated are confident they are acting on their own free will.
Joseph Goebbels
erneboy is online now  
post #3 of 16 (permalink) Old 21-09-2019, 18:44 Thread Starter
Senior Member
 
barryd's Avatar
 
Join Date: May 2008
Location: Richmond North Yorkshire or up an Alp. I like Guitar, Beer and flying around France on a Scooter
My Motorhome: A big White one.
Posts: 27,575
Thanks: 307
Thanked 1,016 Times in 881 Posts
Personal Aire
That's what I thought but I'll see if I can check the specs. If I knacker my laptop I'll be stuffed. No biggie really. This galaxy phone that Eurajohn kindly sent me is fantastic. I only need the laptop for work really now and as I rarely do any I can just mess about online with the phone. Dunno why I hung onto my titchy phone so long.

I'll just plug it straight into the main socket and it will be fine.
erneboy likes this.
barryd is online now  
 
post #4 of 16 (permalink) Old 21-09-2019, 18:49
Senior Member
 
powerplus's Avatar
 
Join Date: Oct 2014
Location: berkshire
My Motorhome: swift sundance 620fb
Posts: 1,151
Thanks: 9
Thanked 122 Times in 116 Posts
Thumbs up

i suspect your first socket comes from the vans controller and if like mine the cable they used is a bit on the small size

and extending it and then putting big load like a compressor is just to much

smaller things should be fine

1 time i had a 300w inverter plugged into the socket in the tv locker to run the tv and the voltage dropped so much that the inverter shut down i then tried a 150w inverter and all was fine

voltage drops quick with 12v and longer runs

this is why they say to use a really thick cable on the solar panel runs

barry
raynipper likes this.

Last edited by powerplus; 21-09-2019 at 18:53.
powerplus is online now  
post #5 of 16 (permalink) Old 21-09-2019, 18:53
Senior Member
 
Matchlock's Avatar
 
Join Date: Jun 2010
Location: Dunstable Bedfordshire
My Motorhome: Auto-Sleeper EK TB LP
Posts: 1,453
Thanks: 37
Thanked 99 Times in 95 Posts
Personal Aire
I bought a 12v extension for my pump so I could reach all the tyres on my van, blew the fuse at the first attempt, the extension was only rated at 10a and the pump startup was a lot higher.
Could have fitted a slow blow fuse but bought a decent pump that connects direct to the battery.
erneboy likes this.

Barry
Matchlock is offline  
post #6 of 16 (permalink) Old 21-09-2019, 20:27
Senior Member
 
raynipper's Avatar
 
Join Date: Aug 2008
Location: Normandy. Just up the D903 from the roundabout with the D15
My Motorhome: Hobby 750 now sold.
Posts: 20,361
Thanks: 1,036
Thanked 367 Times in 347 Posts
Send a message via Skype™ to raynipper
Baz call an electrician quickly or you will bugger up everything.

Ray.

The FSA licensed a twice convicted fraudster to handle our life´s savings. Guess what? He robbed us of £750,000. http://raynipper.com
Brexit is madness orchestrated by the insane.
raynipper is online now  
post #7 of 16 (permalink) Old 21-09-2019, 22:24 Thread Starter
Senior Member
 
barryd's Avatar
 
Join Date: May 2008
Location: Richmond North Yorkshire or up an Alp. I like Guitar, Beer and flying around France on a Scooter
My Motorhome: A big White one.
Posts: 27,575
Thanks: 307
Thanked 1,016 Times in 881 Posts
Personal Aire
I'm usually not too bad with electrics. The pump works fine in that socket without the extension.
barryd is online now  
post #8 of 16 (permalink) Old 21-09-2019, 23:02
Senior Member
 
Devonboy's Avatar
 
Join Date: Nov 2009
Location: Devon
My Motorhome: Rapido 9048DF
Posts: 1,036
Thanks: 94
Thanked 79 Times in 72 Posts
Quote:
Originally Posted by Matchlock View Post
I bought a 12v extension for my pump so I could reach all the tyres on my van, blew the fuse at the first attempt, the extension was only rated at 10a and the pump startup was a lot higher.
Could have fitted a slow blow fuse but bought a decent pump that connects direct to the battery.
Yep I did the same pia.

Dave.
Devonboy is online now  
post #9 of 16 (permalink) Old 22-09-2019, 08:16
Senior Member
 
raynipper's Avatar
 
Join Date: Aug 2008
Location: Normandy. Just up the D903 from the roundabout with the D15
My Motorhome: Hobby 750 now sold.
Posts: 20,361
Thanks: 1,036
Thanked 367 Times in 347 Posts
Send a message via Skype™ to raynipper
Usually 12v sockets in vehicles are fused at 10a and a heavy duty pump will be about 10a but run via a 5m extension you are likely to drop the volts and raise the amps. Can't say exactly but with the vans wiring plus the extension you might be 7 or 8m from the battery and volts could be down to 10 or less depending on quality.

Personally for the odd time you will need to use the pump on tyres I would have the extension lead fitted with crocks and go direct to the battery. Possibly a shorter extension for light loads within the van.

My HD air pump already has 5 or 6m HD lead on it. Many of the air pumps sold today are light and flimsy with feeble leads. When checking the pump box new in the shops it should be about 3kg. in weight. Anything less is going to be crap.

Ray.
erneboy, Penquin and tugboat like this.

The FSA licensed a twice convicted fraudster to handle our life´s savings. Guess what? He robbed us of £750,000. http://raynipper.com
Brexit is madness orchestrated by the insane.
raynipper is online now  
post #10 of 16 (permalink) Old 22-09-2019, 10:10 Thread Starter
Senior Member
 
barryd's Avatar
 
Join Date: May 2008
Location: Richmond North Yorkshire or up an Alp. I like Guitar, Beer and flying around France on a Scooter
My Motorhome: A big White one.
Posts: 27,575
Thanks: 307
Thanked 1,016 Times in 881 Posts
Personal Aire
I think the pumps own lead is maybe 3-5 metres ray so plugged into a 5m extension and then as you say whatever the length of the internal wiring. It's a proper thick extension this but maybe the pump was a bad thing to try.
raynipper likes this.
barryd is online now  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Motorhome Forums, Motorhome Discussion, Motorhome Chat forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome