RED to RED BLACK to BLACK (1 Viewer)

Techno

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I want my baby back :D NOT
Joking aside
Generally RED is +ve POSITIVE / BLACK is -ve NEGATIVE
EXCEPTIONS include blue as +ve brown as -ve (German Vans) and others but generally if you are adding or creating from scratch either be aware and use the same colours or go with the above.
Use a 12 volt meter to establish which is which. The red test lead is positive and the black negative, if you put them on the wires that you are investigating they will give a reading "X" if RED is on the +ve OR "-X" if polarity is reversed. So red on blue black on brown on a hymer as the example will read 12 volts or more rather than -12 volts
IGNORE all confusing words like live and neutral! completely incorrect when discussing DC "Direct current" circuits
This thread is ONLY about DC
Current flows from +ve to -ve
All circuits must have their own fuse. The fuse protects the wire from overheating or catching fire.
The size of the wire must be more than big enough for the current it is expected to carry and the fuse smaller than the wire can handle continuously
To control a circuit involves a switch on/off and this is always placed in the +ve and this too must be rated to carry the maximum current.

This thread will grow legs and run :LOL:
 

Lenny HB

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This thread is ONLY about DC
Current flows from +ve to -ve
Nope sorry to disagree, but Electron current flow go from negative to positive, in practice it is not important and the general convention is to assume it flows from +ve to -ve this is because this is what they believed in the early days, it was years later they discovered they were wrong. :)

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pappajohn

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Nope sorry to disagree, but Electron current flow go from negative to positive, in practice it is not important and the general convention is to assume it flows from +ve to -ve this is because this is what they believed in the early days, it was years later they discovered they were wrong. :)
You mean like coffee and red meat is bad for you.....this week !

Too many scientists with time on their hands.
 
Dec 27, 2014
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Nope sorry to disagree, but Electron current flow go from negative to positive, in practice it is not important and the general convention is to assume it flows from +ve to -ve this is because this is what they believed in the early days, it was years later they discovered they were wrong. :)
Correct
 

SuperMike

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Or as in an RV, white is negative and positive is black. Or any other combination they thought of at the time, depending on what they had available. Also they don't tend to use cable colours or numbering, so for example all cables going rearwards start and finish as black. It's up to you to work out which is what. o_O

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pappajohn

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Or as in an RV, white is negative and positive is black. Or any other combination they thought of at the time, depending on what they had available. Also they don't tend to use cable colours or numbering, so for example all cables going rearwards start and finish as black. It's up to you to work out which is what. o_O
All my blacks were numbered Mike, still doesnt make tracing easy.
 
Dec 27, 2014
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Generally it is wise enough to ignore wire colour in a 12 volt auto circuit... Colours and tracers are only relevant to wiring diagrams and usually change from source to consumer.

In aircraft all wires (generally 28volt !) are all white !
 

SuperMike

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Not my words, but .........

When you SPECIFICALLY say CURRENT, you are referring to current in the sense that it was understood prior to the discovery that the actual carriers were negative.

It actually is BOTH. Allow me to explain.

EXTERNAL TO THE BATTERY (in the circuitry and wiring):
Current ("conventional current" as you could state it to avoid ambiguity) flows from the positive terminal to the negative terminal.

INTERNAL TO THE BATTERY (caution...!):
Current ("conventional current" as you could state it to avoid ambiguity) flows from the negative terminal to the positive terminal.

Think of the battery as a pump. Just as in a water pump, the water flows from low pressure to high pressure because the water is being re-energized by the actions of the pump. External to the pump, in the piping, the water flows from high pressure to low pressure, because the pressure drives the flow to occur.

Similarly, with batteries:

External in the wiring:
The higher voltage "pushes" the current to low voltage.

Internal to the battery:
The battery re-energizes the current via electrochemical reactions as it is "pumped" back to high voltage

Notice that I discussed all of the above without ever once saying "electron"?

That is what you should do when using the word "current", as the word "current" is conventionally understood to mean what it meant to early researchers.

Current is the hypothetical flow rate of positive charges that would create THE SAME FIELD EFFECTS as whatever charges are actually doing the flowing.

That being said, hypothetical positive charges flowing north at a rate of 1.6 Coulombs per second ARE THE SAME CURRENT as 10 quintillion electrons (remember, the electron is negative) per second flowing south.

The current in the above example is directed north. It doesn't matter which direction actual particles flow or which sign the actual particles are.

Current direction is given by:
(sign of charge) * (direction of charge flow)

If sign of charge is positive, then the direction will be the same as the actual flow.
If sign of charge is negative, then the direction will be opposite the actual flow.

That being said...our primary understood carrier of charge is the electron, which is negative. Most man-made circuits are based upon electrons.

BUT, this doesn't mean that ALL circuits are based upon electrons. Some are based upon positive sodium ions, like those in your brain and nerves.

The point is, we need to be flexible and inclusive in our definition of current and charge. We have a convention. Remember what the convention is...it is based upon positive charges. Remember what happens when the sign isn't positive. Remember that it is FIELD EFFECTS that matter.

Don't blame Ben Franklin for guessing wrong. In fact, some have the opinion that he did us a favor in being more inclusive.


Confused, you will be !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :whistle: o_O :sneaky: :LOL:

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Techno

Techno

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There are plenty of connection options. I like these batteries because they offer the traditional connection post but a threaded stud in addition. Even then there can be too many wires but this can be overcome with the addition of such pictured
CA_11081517510469-X2.jpg

CA_11081517514407-X2.jpg
 

andy63

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These gadgets can be handy for tracing wires and locating breaks if you can access the wires
Andy
20151108_184933.jpg

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Techno

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Adding batteries is relatively straight forwards as long as there is space payload and not overly far apart.
These extra pair used 2 metres of red & black 35mm welding cable. Utilising the redundant gas locker on the opposite side of my van.
Increasing battery capacity does of course mean you might have to consider an upgrade to your usual mains charger. Or a B2B unit.
EDIT I used a length of 40mm ID plumbing pipe to take the cables through between the double floor.
CA_11081517504478-X2.jpg

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Last edited:

andy63

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Adding batteries is relatively straight forwards as long as there is space payload and not overly far apart.
These extra pair used 2 metres of red & black 35mm welding cable. Utilising the redundant gas locker on the opposite side of my van.
Increasing battery capacity does of course mean you might have to consider an upgrade to your usual mains charger.
CA_11081517504478-X2.jpg
Adding batteries is relatively straight forwards as long as there is space payload and not overly far apart.
These extra pair used 2 metres of red & black 35mm welding cable. Utilising the redundant gas locker on the opposite side of my van.
Increasing battery capacity does of course mean you might have to consider an upgrade to your usual mains charger.
CA_11081517504478-X2.jpg
With two batteries in parallel as in your picture do you normally take the supply off one battery.. I had been told that I should take - off one and + off the other???
Something about ensuring the load was shared better.
Ta andy
 
R

Robert Clark

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I made a mistake when adding extra batteries
Ordered battery terminal connectors off. eBay. Then when fitting them realised that the two terminals of the battery are different sizes
I'd orders all negatives, and should have ordered half of them as positives

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Techno

Techno

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I made a mistake when adding extra batteries
Ordered battery terminal connectors off. eBay. Then when fitting them realised that the two terminals of the battery are different sizes
I'd orders all negatives, and should have ordered half of them as positives
That's a really good simple observation Robert (y)
I was trying to keep it simple but the hecklers have woke up :LOL:
 

laird of Dunstan

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That's a really good simple observation Robert (y)
I was trying to keep it simple but the hecklers have woke up :LOL:

ignore them techno , its obviously above their abilities to comprehend your modifications to your rapido, I bet they all drive inferior vehicles such as hymers:whistle::)

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May 29, 2013
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Adding batteries is relatively straight forwards as long as there is space payload and not overly far apart.
These extra pair used 2 metres of red & black 35mm welding cable. Utilising the redundant gas locker on the opposite side of my van.
Increasing battery capacity does of course mean you might have to consider an upgrade to your usual mains charger. Or a B2B unit.
EDIT I used a length of 40mm ID plumbing pipe to take the cables through between the double floor.
CA_11081517504478-X2.jpg

Nice, but did you consider the heat build-up effect inside the plumbing pipe ?
 
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Techno

Techno

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They don't approach warm never mind hot.
The maximum current they will ever see is 60 amps and the cable is rated over 4 times that.

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