hooking up house bateries

GregoryHojno · 08-04-2013, 01:44 PM

I just purchased two new Duralast 12 volt (HOUSE)batteries for my 2000 Winnebago diesel pusher/ The problem is how to install them.
I think the old ones were connected like this. a cable from underneath the chasis (red in color) to the positive terminal, then a red pigtail from the positive terminal to the positive terminal of the second battery. A black pigtail from the negative post of the first battery to the negative post of the second battery then a cable from the negative post of the second battery to the frame of the coach. Is this correct? ....or should I put connect the red chasis cable to the positive post of the first battery, then connect a pigtail from the negative post of the first battery to the positive post of the second battery, and a pigtail from the negative post of the second battery to the positive post of the first battery, and then the cable to the frame?
I'm so confused. HALP!!!

RoyM · 08-04-2013, 01:54 PM

Your first hookup is the correct one, + to+, - to -. This will give you twelve volts but double the amperage which is what you want. The second will hook the batteries in series which would supply 24 volts. That tends to fry stuff.

Capn_Dave · 08-04-2013, 01:56 PM

The first way. Connect Positive to positive and negative to negative

Fair Winds
Dave

jerichorick · 08-04-2013, 03:48 PM

Always hook the positives up first. Make certain that everything is as clean and shiny as you can get it. Clean any white power or other corrosion off with a solution of baking soda and water. No special formula. A teaspoon or so to a full glass of water will do. Let it sit for an hour then wash it off with clean water.

I grease my terminals and then wipe the excess off. Place the red cable and the jumper on the positive post, as you have been encouraged to do, and the free end of the jumper to the other battery + terminal. Tighten securely but don't over tighten because this could damage the internal connection to the plates. When connecting the negative wire and jumper you may get a fairly healthy snap from your inverter capacitor as it charges. A switch can be used connected from the negative wire to the negative terminal with alligator clips. When you close the sw the spark is isolated to it. Quickly touch the battery - wire to the - terminal and remove the sw. The cap won't discharge real fast but it will cause a spark again in a few minutes. always use care and never wear rings or short the + and - together with the wrench. Very common problem.

Have fun!

Rick

wa8yxm · 08-04-2013, 04:29 PM

Someone said "Always look at the positives first"

No.. You always look at the EXISTING batteries first.. THEN you go shopping for new ones.. Alas you did not do that so you have to make changes.

12 volt are wired like this

-Battery+
-Battery+

Six volt like this
-Bat+-ery+

In all cases the left most column is chassis ground and the right most runs off to the fuse block. converter et-al.

John Hilley · 08-04-2013, 04:38 PM

I am not a fan of putting grease on the battery terminals. A little vaseline or dielectric grease on the terminal after the connection is made might be beneficial. Those anti corrosion felt pads seem to be effective

jerichorick · 08-05-2013, 06:37 AM

This was a common practice in the phone co. We worked with low dc and high current. Wiping excess off it the key. The felts and a terminal spray is good too. But maintenance is the key to keeping this in good condition. I should have been more specific about the grease. Dielectric or hard grease is what we used, very sparingly.

DW just got up so coffee and a seat out under the awning to enjoy this beautify and cool morning in WV!

Rick

LJowdy · 08-08-2013, 12:00 PM

Although I don't think it was covered, the red (pos) cable from the coach should be hooked up the the 1st battery and the negative cable (black) should be hooked up the 2nd battery. This ensures that the current is traveling through both batteries. This holds true regardless of how many batteries you use or if you use 6 volt batteries vs 12 volt batteries. (the difference between using 4 6 volt batteries ann 2 12 volt batteries is you quadruple your amperage) My 2011 Tour came with 2 12 volt house batteries and I replaced them with 4 Lifeline 6 volt batteries as I do a lot of dry camping. The 6 volt batteries last a lot longer between charging.

jerichorick · 08-09-2013, 05:49 AM

Quote:

Originally Posted by LJowdy

Although I don't think it was covered, the red (pos) cable from the coach should be hooked up the the 1st battery and the negative cable (black) should be hooked up the 2nd battery. This ensures that the current is traveling through both batteries.

Please forgive my ignorance here. If the parallel batteries are connected with good clean connections how is placing the cables as described above going to affect the current? Physically it makes no sense. If a battery is bad in the multi-battery string the placement of the cables will not increase the current or assure a better run time. Not in my experience. My past life job was installing and maintaining battery strings for the phone company. If you can convince me, I am very willing to learn your sound reasoning.

LJowdy · 08-09-2013, 09:16 AM

Regardless if you're using 2 or 4 (12 volt) batteries or 2 or 4 (6 volt) Every battery company, motorhome manufacturer and inverter company highly recommends that the positive cable be placed on the 1st battery in the string and the negative cable on the last battery in the string. They, and I have found that if you DON'T do this, the charging of the battery is centered mainly on the 1st battery. The idea is to have the current run through all the batterys during discharg and through the charge process. I found out the hard way back in 1993 when I purchased a Holiday Rambler that came with 2 (12 volt) batteries. When I bought the coach, it didn't have an inverter so I purchased a 2000 watt unit from Camping World back when you used to get some great coupons in the mail. Next, I purchased 4 deep cycle golf cart 6 volt batteries. When I installed the Inverter, the cables only reached the first battery so that's how I hooked it up. The first battery, over the course of a year slowly began to fade. Sams club exchanged the battery and during that time, I called Xantrex (Inverter manufacturer) and spoke to my friend who owns a Trailer/Motorhome supply company and a repair facility. The first thing each of them asked is how I had the inverter wired up. After speaking to them, I went to a welding shop and bought some "0" welding cable and extended the cables on the Inverter to allow the negative cable to reach the last battery in the string. That solved the problem and the batteries lasted for years. Later I spoke to an electrical engineer who worked for GM during their experimental phase with battery powered cars as well as a Ford electrical engineer, Both of them told me the same thing, current must run totally through all the batteries during charge and discharge. (Before I retired from the L.A. County Sheriff's Dept., my last job was as the Fleet Manager (didn't get shot at and it sort of assured me that I'd be able to retire alive or with no bullet holes.) This put me in touch with some high power engineers as we were always working with GM and Ford developing Law Enforcement vehicles.

If this is contrary to your belief or experience I can't do anything about that but pass on the knowledge I gained from people a lot smarter than I am when it comes to matters relating to this subject.

To expound, (2) 6 volt batteries are wired together Parallel. Then the next (2) 6 volt batteries are wired together Parallel. Finally the 2 banks of batteries are wired together in series to make the total output 12 volts.

SCVJeff · 08-09-2013, 07:23 PM

What everyone is trying to say but not really getting there is that when you have series/ parallel batteries as any of us with 4ea. 6v batteries do, there are jumpers between them (obviously). What happens is that those who are anal about proper charge and discharge across all batteries equally, have identical lengths between the 2 series batteries, as well as when paralleling the 2 sets of series'ed 6v batteries. It's the minute losses in the cables that everyone is talking about that will actually unbalance the group. If you look at the bottom picture above this post, it is incorrect. What you want is to move the pos or neg to the other set of battery terminals, so the length of all jumpers and their losses are exactly the same when viewed by the charger. If I wasn't doing this on an iPad I would post illustrations of this.

wlf00 · 08-10-2013, 04:01 PM

Jeff is right on. By hooking up the main battery cables to the opposite corners of the block of batteries, all of the cable lengths are the same forcing the same current to go through each of the batteries.

If this were not the case, then the batteries with the shorter overall cable length would receive more current when being charged, reach a slightly higher voltage after being charged, and provide most of the current when supplying the load. This results in an uneven wear on the batteries.

Always hook up to the opposite corners.

skigramp · 08-10-2013, 09:44 PM

Quote:

Originally Posted by LJowdy

To expound, (2) 6 volt batteries are wired together Parallel. Then the next (2) 6 volt batteries are wired together Parallel. Finally the 2 banks of batteries are wired together in series to make the total output 12 volts.

I think you have the words Parallel and Series exactly backwards ...

To expound, (2) 6 volt batteries are wired together in series to form a 12 Volt bank. Then the next (2) 6 volt batteries are also wired together in series. Finally the 2 banks of batteries are wired together in parallel to make a new bank of batteries with output 12 volts but with (theoretically) twice the amperage.

DAN L · 08-11-2013, 01:58 AM

Quote:

Originally Posted by jerichorick

Please forgive my ignorance here. If the parallel batteries are connected with good clean connections how is placing the cables as described above going to affect the current? Physically it makes no sense. If a battery is bad in the multi-battery string the placement of the cables will not increase the current or assure a better run time. Not in my experience. My past life job was installing and maintaining battery strings for the phone company. If you can convince me, I am very willing to learn your sound reasoning.

check this resource.

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

John Hilley · 08-11-2013, 07:47 AM

Quote:

Originally Posted by jerichorick

Please forgive my ignorance here. If the parallel batteries are connected with good clean connections how is placing the cables as described above going to affect the current? Physically it makes no sense. If a battery is bad in the multi-battery string the placement of the cables will not increase the current or assure a better run time. Not in my experience. My past life job was installing and maintaining battery strings for the phone company. If you can convince me, I am very willing to learn your sound reasoning.

Quote:

Originally Posted by DAN L

check this resource.

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

It isn't going to affect the current, but it will determine which batteries get drawn down the most.

bobpie · 08-11-2013, 08:02 AM

Dan L, Great info. Thanks. Just added to my favorites.

jerichorick · 08-12-2013, 06:06 AM

Thank you both, Dan and John, for correcting this old man's tradition. I like method 3 over 4 because of the neetens of it. I have been thinking about this since I wrote my 'errored message' and was starting to consider what you showed in that link.

Tradition: A mom was preparing a ham to bake. Her daughter asked why she always cut the end off and placed it on top of the main ham? Mom told her that her mother did it that way. Let's ask grama why! A call to grama answered the question clearly.

"The pan I had was too small for the ham so I cut the end off."

I guess the phone co taught me to 'cut the end off'! Forgive my ignorance folks.