Author |
Share Topic Topic Search Topic Options
|
Guests
Guest Group
|
Topic: Battery Issues Posted: 21 Jun 2015 at 4:54pm |
Originally posted by CharlieM
Either lead is OK though convention is to put it in the positive lead.
|
Not to be a contrarian, but I just installed a cutoff switch on my 178 dual bank and all my research recommends using the negative side for safety issues. See Youtube video below:
|
 |
techntrek
Admin Group - pHp
Joined: 29 Jul 2009
Location: MD
Online Status: Offline
Posts: 9062
|
Posted: 21 Jun 2015 at 10:00pm |
NHRA rule is on the positive side. Positive side seems to be the norm for the RV industry.
|
|
 |
JohnBG
Senior Member
Joined: 14 Apr 2015
Location: Deltona, FL
Online Status: Offline
Posts: 190
|
Posted: 21 Jun 2015 at 10:21pm |
I have done low voltage alarm systems for 20+ years and the only way to be certain is to yank the positive lead. You can still complete a circuit downstream with a screwdriver touching a terminal too close too the edge of a j box and make some sparks.
Best to think of batteries as little electrical bombs. A small 12AH battery will give you 1 amp for 12 hours, 2 amps for 6 hours, 3 amps for 4 hours or a metric buttload of amps for just a few seconds. I accidentally spot welded a wrench to my motorcycle frame years ago being careless while disconnecting the small battery.
I hesitate to think what a big RV battery can weld. Then again I'm an n00b to RV's...
|
2010 R-Pod RP-171
2010 Honda Ridgeline TV
|
 |
R-Pod'nFJ
Newbie
Joined: 04 Apr 2015
Online Status: Offline
Posts: 37
|
Posted: 21 Jun 2015 at 10:22pm |
Doesn't the antenna booster draw a lot of electricity also? I can't remember if it can even turn on unless the Pod is plugged into a power source. I also turn off the backlighting on the radio as well.
|
14 Cement Gray FJ Cruiser
15 R-Pod 179
71 Honda CB750 cafe racer project
71 Honda CB350
75 Honda XL350
81 KZ550 Ltd. street tracker project
Scott & Kerri
|
 |
Tars Tarkas
Senior Member
Joined: 14 Jan 2013
Location: Near Nashville
Online Status: Offline
Posts: 1454
|
Posted: 22 Jun 2015 at 12:11am |
I'd probably put the switch on the positive side if I were to install one, just because that's where most people put it and therefore, if the occasion ever arose, that's probably where they'd look for it if they had to.
The NHRA is concerned with spilled gasoline and cutting off engines after wrecks and they require battery cutoffs on the dash where they are easily accessible by rescuers.
The idea of a wrench or screwdriver shorting things out doesn't apply once a switch is installed, unless you really make an effort to short the circuit. Once the switch is flipped on the positive or negative side the circuit is open and there are no more electrons to cause sparks.
The fact that electricity flows from the negative side of the battery to the positive kind of argues for switching the negative side -- cutting off the electricity at the source, but they all stop moving no matter where the circuit is opened.
This is an interesting subject to Google, if you're interested in this kind of thing. There are strong opinions on both sides of the argument.
TT
|
2010 176
FJ Cruiser
|
 |
Guests
Guest Group
|
Posted: 22 Jun 2015 at 5:58am |
Originally posted by Tars Tarkas
This is an interesting subject to Google, if you're interested in this kind of thing. There are strong opinions on both sides of the argument. TT
|
Actually, there are 3 sides to the argument. After doing more research by asking "the Google" I've come to the opinion that if you asked 3 "experts" you'd get 3 different answers: - Positive
- Negative
- It really doesn't matter one way or the other
I'm inclined to side with expert #3
|
 |
techntrek
Admin Group - pHp
Joined: 29 Jul 2009
Location: MD
Online Status: Offline
Posts: 9062
|
Posted: 22 Jun 2015 at 6:03pm |
Are you positive, or being negative about it? This subject is very charged.
|
|
 |
sailor323
Senior Member
Joined: 11 Jun 2015
Location: S Central KY
Online Status: Offline
Posts: 281
|
Posted: 22 Jun 2015 at 6:29pm |
Putting the switch on the positive side is the safer choice. The reason is simple. If there is some kind of grounding of the positive wire between the battery and the pod, there is a significant risk of fire. Disconnecting the positive side eliminates that risk, while switching the negative side does not. Switching the negative side leaves the positive wire hot. A major no-no in electricity. Essentially, if you put the switch on the negative side, you have not disconnected the battery from the pod.
|
 |
Tars Tarkas
Senior Member
Joined: 14 Jan 2013
Location: Near Nashville
Online Status: Offline
Posts: 1454
|
Posted: 22 Jun 2015 at 7:58pm |
Originally posted by sailor323
Putting the switch on the positive side is the safer choice. The reason is simple. If there is some kind of grounding of the positive wire between the battery and the pod, there is a significant risk of fire. Disconnecting the positive side eliminates that risk, while switching the negative side does not. Switching the negative side leaves the positive wire hot. A major no-no in electricity. Essentially, if you put the switch on the negative side, you have not disconnected the battery from the pod.
|
If the switch is between the negative battery post and the ground, which it pretty much has to be, then there is no danger of spark from a positive wire. There would be no negative to the ground. Sparks happen when the circuit is closed from positive to negative (not to ground). TT
|
2010 176
FJ Cruiser
|
 |
sailor323
Senior Member
Joined: 11 Jun 2015
Location: S Central KY
Online Status: Offline
Posts: 281
|
Posted: 22 Jun 2015 at 8:06pm |
Originally posted by Tars Tarkas
If the switch is between the negative battery post and the ground, which it pretty much has to be, then there is no danger of spark from a positive wire. There would be no negative to the ground. Sparks happen when the circuit is closed from positive to negative (not to ground).
TT
|
Good point, TT and in fact explains why it doesn't really matter which side is switched.
|
 |