Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 03-17-2016, 08:07 AM   #201
Senior Member
 
hammer55's Avatar
 
Join Date: Jan 2015
Location: central valley, california
Posts: 498
never seen solid wire from or to a battery, just sayin

Quote:
Originally Posted by OldBob View Post
Don't use stranded wire. You need solid battery cable. I got mine at Walmart. They have battery cable in 2, 4, and 6 gauge sizes at reasonable prices. 4 gauge is perfect for the job.
__________________
Mark & Annie
2014 COACHMEN PURSUIT 27 KB
Modesto, Central California
hammer55 is offline   Reply With Quote
Old 03-17-2016, 08:48 AM   #202
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
I'm pretty sure stranded carries more current than solid?
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 03-17-2016, 08:49 AM   #203
jkoenig24
 
Join Date: Apr 2015
Location: Box Elder, SD (formerly NY)
Posts: 816
Stranded wire WILL carry more current AND, will be MUCH easier to bend and work with.
jkoenig24 is online now   Reply With Quote
Old 03-17-2016, 08:55 AM   #204
Senior Member
 
SeaDog's Avatar
 
Join Date: Jan 2016
Location: Idaho
Posts: 8,843
Actually there is no difference in the current carrying ability of stranded or solid in the same wire size. The difference is in the space required for the wire. Stranded is much larger in physical size then solid however it is much easier to bend and conform to curves and such.
__________________
Retired Navy
Jake my sidekick (yellow Lab) 10/04 - 05/20
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho
SeaDog is offline   Reply With Quote
Old 03-17-2016, 09:43 AM   #205
Senior Member
 
hammer55's Avatar
 
Join Date: Jan 2015
Location: central valley, california
Posts: 498
true, electricity flows on the outside of the wire, I have always used motor lead wire, it has a higher amp rating, and it is much easier to work with and makes hooking up motors in the pecker head(motor junction box much easier,,,,

Quote:
Originally Posted by SeaDog View Post
Actually there is no difference in the current carrying ability of stranded or solid in the same wire size. The difference is in the space required for the wire. Stranded is much larger in physical size then solid however it is much easier to bend and conform to curves and such.
__________________
Mark & Annie
2014 COACHMEN PURSUIT 27 KB
Modesto, Central California
hammer55 is offline   Reply With Quote
Old 03-17-2016, 11:22 AM   #206
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,001
Quote:
Originally Posted by hammer55 View Post
true, electricity flows on the outside of the wire, I have always used motor lead wire, it has a higher amp rating, and it is much easier to work with and makes hooking up motors in the pecker head(motor junction box much easier,,,,
As I understand it:

In an AC current, current flows along the outside (skin) of the conductor and the depth of penetration is due to the circulating eddy currents (arising from a changing inductance field from the current alternating direction). These eddy currents cancel the current flow in the center of a conductor and reinforcing it in the skin. The higher the frequency of the alternating current, the more pronounced this effect.

Known as the "Skin Effect" you can get more info here:

https://en.wikipedia.org/wiki/Skin_effect

DC current goes through the wire in one direction only; basically an electron gets pushed in one end knocking an electron off the other.

A solid conductor will move DC current slightly more efficiently than stranded of similar gauge. However, for a similar current flow demand (wattage) a solid wire would have to be thicker and thus more inflexible (more like a Buss Bar than a wire). That is why battery wires in automobiles are made up of very thick stranded wire.

To reduce resistance in the connection between 2 6 volt deep cycle batteries, use the shortest heaviest battery cable you can find. O or even OO would be best.

6" AWG 1/0 Red Battery Interconnect Cable 3/8" Lugs Battery Banks

http://www.amazon.com/Battery-Interc...WJ212VKWX5V48M12" AWG 2/0 Red Battery Interconnect Cable 3/8" Lugs Battery Banks
Attached Thumbnails
Click image for larger version

Name:	ohms-law-illustrated.gif
Views:	59
Size:	142.3 KB
ID:	102145   Click image for larger version

Name:	330px-Skineffect_reason.svg.png
Views:	43
Size:	19.8 KB
ID:	102146  
__________________
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 03-17-2016, 12:13 PM   #207
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,471
The difference in resistance is very minimal 0 gauge = .00032 ohm/meter. 4 gauge = .00081 ohm/meter.
4 gauge would work just fine between your batteries.
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank (Two-GC2) - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is offline   Reply With Quote
Old 03-17-2016, 07:09 PM   #208
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by Herk7769 View Post
As I understand it:

In an AC current, current flows along the outside (skin) of the conductor and the depth of penetration is due to the circulating eddy currents (arising from a changing inductance field from the current alternating direction). These eddy currents cancel the current flow in the center of a conductor and reinforcing it in the skin. The higher the frequency of the alternating current, the more pronounced this effect.

Known as the "Skin Effect" you can get more info here:

https://en.wikipedia.org/wiki/Skin_effect

DC current goes through the wire in one direction only; basically an electron gets pushed in one end knocking an electron off the other.

A solid conductor will move DC current slightly more efficiently than stranded of similar gauge. However, for a similar current flow demand (wattage) a solid wire would have to be thicker and thus more inflexible (more like a Buss Bar than a wire). That is why battery wires in automobiles are made up of very thick stranded wire.

To reduce resistance in the connection between 2 6 volt deep cycle batteries, use the shortest heaviest battery cable you can find. O or even OO would be best.

6" AWG 1/0 Red Battery Interconnect Cable 3/8" Lugs Battery Banks

Amazon.com: 12" AWG 2/0 Red Battery Interconnect Cable 3/8" Lugs Battery Banks, Off Grid Applications DURABLE LONG LASTING ASSEMBLED IN THE USA: Automotive12" AWG 2/0 Red Battery Interconnect Cable 3/8" Lugs Battery Banks

Thanks for the link, Herk, I'm going to order one of those tonight.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 03-17-2016, 08:15 PM   #209
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,583
Quote:
Originally Posted by Too Tall View Post
Thanks for the link, Herk, I'm going to order one of those tonight.
Of course,Boondocking is exactly right. For a 12 inch cable at 200 amps, the difference between #4 and #00 in voltage drop is 34 millivolts or less than .3%...and 200 amps is a heavy load. The rest of the system (cable to loads, power panel, solenoids, etc) will drop a heck of a lot more and totally dominate.

By the way, stranded vs solid will add another millivolt for #4 and .3 millivolts for #00. I wouldn't want to even try to work with solid #00 copper.

Now, since the #00 cables are available, might as well buy them but your system probably has 30 feet of #4 or #6 in it anyway between the batteries and the loads...and back!
__________________

2015 335DS
ScottBrownstein is online now   Reply With Quote
Old 03-17-2016, 09:45 PM   #210
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by ScottBrownstein View Post
Of course,Boondocking is exactly right. For a 12 inch cable at 200 amps, the difference between #4 and #00 in voltage drop is 34 millivolts or less than .3%...and 200 amps is a heavy load. The rest of the system (cable to loads, power panel, solenoids, etc) will drop a heck of a lot more and totally dominate.

By the way, stranded vs solid will add another millivolt for #4 and .3 millivolts for #00. I wouldn't want to even try to work with solid #00 copper.

Now, since the #00 cables are available, might as well buy them but your system probably has 30 feet of #4 or #6 in it anyway between the batteries and the loads...and back!
Yea, good point. And I don't think I'll ever run anything in the camper that would draw more than a few amps.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 03-17-2016, 09:59 PM   #211
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,001
Remember that we are talking about the inter-battery connection.

While the load wires can be what ever size is appropriate, putting an unnecessarily high resistance between cell 3 and 4 of your 12 volt (6 cell) battery will make balancing the two 6 volt batteries (each with 3 cells) difficult.

The internal connection between cells inside the battery is a solid lead buss bar for a reason.

You can certainly do whatever you want.
__________________
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 03-18-2016, 03:36 AM   #212
Senior Member
 
Join Date: Mar 2015
Location: Florida
Posts: 394
Quote:
Originally Posted by hammer55 View Post
never seen solid wire from or to a battery, just sayin
Mark...I'm sure you are right. I'm not sure what I was thinking. I get a bit forgetful as time goes on...
__________________
OldBob

I may be old but I'm trying, very trying.
2015 RAM 1500 - EcoDiesel
Rockwood Ultra V 2715VS
OldBob is offline   Reply With Quote
Old 03-18-2016, 07:38 AM   #213
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,001
Quote:
Originally Posted by OldBob View Post
Mark...I'm sure you are right. I'm not sure what I was thinking. I get a bit forgetful as time goes on...
I am sure if there was a way of making that connection a solid copper bar without doubling the cost and weight of the car they would do it.
__________________
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 03-18-2016, 10:07 AM   #214
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by Herk7769 View Post
Remember that we are talking about the inter-battery connection.

While the load wires can be what ever size is appropriate, putting an unnecessarily high resistance between cell 3 and 4 of your 12 volt (6 cell) battery will make balancing the two 6 volt batteries (each with 3 cells) difficult.

The internal connection between cells inside the battery is a solid lead buss bar for a reason.

You can certainly do whatever you want.
Sure, I would think the inter-connect between two 6 volts is more critical since they are in series and you goal is a clean resistance free (as possible) connection to produce 12 volts capable of performing as well as a singe 12 volt battery of equivalent size.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 03-18-2016, 12:06 PM   #215
Senior Member
 
hammer55's Avatar
 
Join Date: Jan 2015
Location: central valley, california
Posts: 498
The longer the run the more resistance it has, and the higher the amperage the bigger the wire you need, you are sizing the wire for two things, to limit the resistance and to accomodate the amperage, bigger doesn't hurt, well it might bother the pocket book, but better for the quality of the power you are transmitting, and resistance causes heat, which reaks havoc on a circuit
__________________
Mark & Annie
2014 COACHMEN PURSUIT 27 KB
Modesto, Central California
hammer55 is offline   Reply With Quote
Old 03-18-2016, 12:13 PM   #216
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,001
Quote:
Originally Posted by Too Tall View Post
Sure, I would think the inter-connect between two 6 volts is more critical since they are in series and you goal is a clean resistance free (as possible) connection to produce 12 volts capable of performing as well as a singe 12 volt battery of equivalent size.
The same logic applies when connecting 12 volt batteries in a parallel bank. Short and as big a gauge as you can find/afford.
Attached Thumbnails
Click image for larger version

Name:	BattereiswiredinSeriesParallel.gif
Views:	48
Size:	30.5 KB
ID:	102255  
Attached Files
File Type: pdf How to correctly interconnect multiple batteries to form one larger bank.pdf (106.1 KB, 8 views)
__________________
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 03-18-2016, 12:52 PM   #217
Senior Member
 
PokerDealer's Avatar
 
Join Date: Feb 2012
Location: NowthWest
Posts: 126
So here is my proposal. I have 2 T 105‘s that are six months old. They have been sitting in my house since October. They have a 6ga cable that connects them together. They have no load. I put them on my charger once a month. I read their voltage every other week or so with my multi meter. 48 hours after charging they read 12.85. If i replace the 6ga cable with a 0\2 or 0\4 would they read differently. How would they be different?
__________________
2015 Wildwood 181 BHXL. 2005 1500 Ram Hemi 4x4 W/package
PokerDealer is offline   Reply With Quote
Old 03-18-2016, 12:54 PM   #218
Member
 
Join Date: Sep 2013
Posts: 55
Trying to figure out 6 volt batteries

Without current flowing, no difference


Sent from my iPhone using Tapatalk
rzrnaz is offline   Reply With Quote
Old 03-18-2016, 01:15 PM   #219
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 23,001
Quote:
Originally Posted by rzrnaz View Post
Without current flowing, no difference


Sent from my iPhone using Tapatalk
Even with current you won't see a difference in voltage since the voltage delta would be too small for most home voltmeters. Where you will notice a difference is in battery longevity as one of the 6 volt batteries will be more heavily tasked when providing current and will be charged "ahead" of the other during charging. This unequal treatment will effect the depth of discharge between the two batteries and the number of potential charge/discharge cycles.

Thus the "unbalanced" loading I mentioned previously.

Bank batteries (6 or 12 volt systems) work best when matched by manufacturer, age, cycles, depth of discharge, and "inter-battery/cell resistance".
__________________
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 03-18-2016, 01:49 PM   #220
Senior Member
 
Join Date: Jan 2015
Location: Englewood FL
Posts: 2,583
Quote:
Originally Posted by Herk7769 View Post
Even with current you won't see a difference in voltage since the voltage delta would be too small for most home voltmeters. Where you will notice a difference is in battery longevity as one of the 6 volt batteries will be more heavily tasked when providing current and will be charged "ahead" of the other during charging. This unequal treatment will effect the depth of discharge between the two batteries and the number of potential charge/discharge cycles.

Thus the "unbalanced" loading I mentioned previously.

Bank batteries (6 or 12 volt systems) work best when matched by manufacturer, age, cycles, depth of discharge, and "inter-battery/cell resistance".
Actually, that is not really true. The two 6 volt batteries are in series, you cannot charge or discharge one without the same current flowing from/to the other. When you charge them, the same voltage will be applied (and dropped by each battery.) Herk is correct in that if they are different in any way, one battery(or cells within a battery) will potentially drop a shade more or less voltage than the others, resulting in the other series battery (or cells) seeing a more or less voltage across it in order to recharge and hence a slightly lower final SOC and different specific gravity. In actual fact, they will never be exactly the same anyway, even if they are the same manufacturer and exactly the same age and this is equally true of the cells within each battery as well. That is why vendors recommend occasional "equalization" (only when needed) where you up the voltage way beyond the normal recharge voltage (like above 15 volts and carefully monitor the current) in order to equalize the charge state of all the cells and bring the specific gravity of all of the cells to exactly the same level.

Parallel banks are way different. The current will choose to flow through the path of least resistance. Make sure that each parallel battery has EXACTLY the same cables and cable length to the converter and the RV. If they are different you will eventually find one battery being overused and the other "loafing." After a significant time this will result in one battery ageing faster than another and a loss of total bank capacity.

In series installations...the current has no choice! But when comparing #4 to say #2, or #0, at some reasonable but relatively high charge or discharge current (like 100 amps) we aren't talking volts, we are talking millivolts and only a few at that! Even in a parallel bank installation, a short inter battery cable makes little practical difference, as long as it can handle the current that you want from the bank when it is in use. The total resistance and resulting voltage drop is proportional to the length of the cable, and these are only 6" to 1 foot.

Spend more time worrying about how corroded the lugs are on the batteries...now there is a place to drop some voltage and generate significant heat at the same time...and make sure they all have sufficient water to totally cover the plates at all times.
__________________

2015 335DS
ScottBrownstein is online now   Reply With Quote
Reply

Tags
battery

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


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 05:02 PM.