Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-02-2009, 04:48 PM   #15
Silver Mist
 
LI Pets's Avatar
 
1977 31' Sovereign
Riverhead , New York
Join Date: Aug 2006
Posts: 3,008
Images: 28
Quote:
Originally Posted by jimmini View Post
If you use 2 6V batteries and one goes bad you have NO 12V system.
If you use 2 12V batteries and on goes bad you still have one to power your 12V system..
Good point, can you mix the batteries?

2 6V and 1 12V

or maybe the best bet is 4 6Volts
__________________

__________________
Bob
'77 Sovereign Intl 31' CB
WBCCI R2 Rep VAC 11411 Metro NY VP

LI Pets is offline   Reply With Quote
Old 10-02-2009, 04:52 PM   #16
Rivet Master
 
DaveFL's Avatar
 
2000 31' Land Yacht
Central , Florida
Join Date: Aug 2007
Posts: 1,479
Images: 15
If you don't dry camp why change. Simplest change if you are going to replace batteries due to age would be to go to a type 31 deep cycle, more amp hours without much difference in size and weight.
__________________

__________________
DaveFL is offline   Reply With Quote
Old 10-02-2009, 05:40 PM   #17
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,813
Images: 12
Automotive batteries are NOT suitable as "house batteries" as they are designed for EXTREME amperage draw in short bursts of time. House batteries are of a different design internally and are designed for slower discharge, longer discharge, and deeper discharge. An automotive battery subjected to a deep discharge (to 0 terminal voltage) will be irrevocalbly damaged and in many instances, distroyed, while a deep cycle battery will not be the worse for wear after many such discharges.

What is the designation for HOUSE BATTERIES?
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 10-03-2009, 05:48 AM   #18
Silver Mist
 
LI Pets's Avatar
 
1977 31' Sovereign
Riverhead , New York
Join Date: Aug 2006
Posts: 3,008
Images: 28
Quote:
Originally Posted by jimmini View Post
If you use 2 6V batteries and one goes bad you have NO 12V system.
If you use 2 12V batteries and on goes bad you still have one to power your 12V system..
Good point, can you mix the batteries?

2 6V and 1 12V

or maybe the best bet is 4 6Volts
__________________
Bob
'77 Sovereign Intl 31' CB
WBCCI R2 Rep VAC 11411 Metro NY VP

LI Pets is offline   Reply With Quote
Old 10-03-2009, 02:54 PM   #19
1 Rivet Member
 
DubleDeuce's Avatar
 
1982 31' Airstream310
Lilburn , Georgia
Join Date: May 2009
Posts: 17
<<What is the designation for HOUSE BATTERIES?>>

Do you mean what constitutes a house battery in a motorhome or, what technical designation does a house battery have?

Batteries are batteries. Hook 'em up and go. Their output, amps (electricity) and volts (electrical pressure) are not destingushible to the appliances found on a motor home.

The ISSUE of what constitutes a house battey is essentially a simple one, that battery (or batteries) that make up the power source to run the various appliances in the motor home. these can be lights (powered off of the direct batter terminals) that are of the 12V pursuasion) or any of the 110V appliances that are run off of the vehicles power inverter, which draws its power from the "house batteries".

The distinction above is accurate and workable as for as is goes. But in operation the two types of batteries manufactured in the world for the purposes of automotive use are not the same internally. The two types of batteries are "automotive" and deep cycle". House batteries are generally of the deep cycle variety.

In operation, "house use" batteries must sustain long periods of negative discharge and still hold SOME minimal terminal voltage. The inverter will draw down the current (think of current as gallons of gasoline) and convert it to a higher operating voltage. (110V) But eventually, the terminal voltage will fall to a very low point and the effectiveness of the converter to continue to provide minimal voltage (110V) will fail. Many units have an internal automatic "cutoff" switch to prevent heat damage to the converter or appliances due to "low voltage".

As for the batteries themselves, they don't care one way or the other. their internal construction will permit them going all the way to 0 terminal volts (ask any fisherman WHY he carries a paddle in the boat) and when it comes time to recharge them they respond in kind and take the charge. It is worth noting here that even a "deep cycle" battery has only so many charge/discharge cycles in its lifetime and eventually they must be replaced as a group.

Automotive batteries on the other hand have a totally different job function. Their job is to prvide INSTANT and sustained (for a short period of time) amperage at a minimum terminal voltage (usually 9.5V) for the purposes of getting the engine to start in very cold conditions. This requirement can exceed 2000 amps in certain conditions (0 degrees F and a large diesel engine). For this job several batteries are grouped together in paraell to deliver the required amperage.

The type of battery needed for this job MUST have low internal resistance in order to deliver such massive amounts of current and mantain minimal terminal voltage. An automotive rated battery cannot sustain a total discharge (to 0 terminal voltage) and be brought back to life and be expected to last through its normal life time (think of warranty time). Sooner or later, it will fail prematurely.

The difference in the two types of batteries are to be found in their construction. I won't go into great detail here other that to say that one type, deep cycle, are more expensive to produce, than are the automotive type. And, because of the differences, they are not candidates for interchanging into the motorhome system as a function of OEM design.

True, one type can be used in place of the other for a short length of time, but irrepairable damage will come to the automotive type while the deep cycle type might not be able to deliver the "zing" needed on initial start.

THAT is the difference in house batteries. Do NOT look for the designation "House Battery" when shopping for them. You must ask for deep cycle.

The Deuceman




__________________
DubleDeuce is offline   Reply With Quote
Old 10-03-2009, 03:57 PM   #20
1 Rivet Member
 
DubleDeuce's Avatar
 
1982 31' Airstream310
Lilburn , Georgia
Join Date: May 2009
Posts: 17
...(and, also, maybe to figure out how to get a charge from the alt while driving).

You did not mention the towing vehicle make or model.

The solution to charging the "house batteries" while driving is a simple one. LONG, but simple. Source a constant duty rated (NOT a BOSCH type plug in) power relay (about 60 bucks) and mount it in the engine compartment. Using the RATED power of the vehicles' alternator as a guide, select a wire gauge appropriate to handle the expected charging load. (If your house batteries are very low and you attempt to charge from the towed vehicle, the initial charge rate will be quite high so chose wire gauge accordingly)

Run a separate switch (with control wire) to the power solenoid control terminal. Some power relays are base grounded (ground through the mounting base and have only ONE control terminal) while other power solenoids have TWO control terminals. The two terminals are actually the beginning and the end of a coil of wire. To make this relay work you will need to apply power to one terminal (it does NOT matter which one) and route the other terminal to a ground source. Applying power to the non-grounded terminal will cause the relay to operate and will connect the two large terminal lugs electrically.

Route one of the large terminal lugs to the positive battery terminal (or equivalent) Route the other terminal lug along the vehicle frame to a point meeting at the trailer electrical plug connection. The plug will have to be upgraded to a large capacity 9 position trailer power plug. You can use the center plug for the hot lead into it.

On the trailer side of the connector plug, continue to route the same gauge wire onto the trailer tongue and into the trailer (I guess duct tape and a large 2" hole in the side of the trailer will do)

Once inside the trailer and at the house battery positive lead (it can even be attached at the shore power connection point) connect the alternator lead.

You have a couple of options on how to control the charging system. If you want to throw caution to the wind, just hook up the solenoid control wire to the "HOT in run" position of the key switch. OR, if you want more control, mount a House battery CHARGEON/CHARGE OFF switch on the dashboard between the solenoid control terminal and HOT in run key position. Under NO circumstances should you hook the switch to a constant HOT source as it COULD cause an unintended back feed if you leave the switch on accidentally and a short were to occur. It is also a good idea to fuse the circuit at 100 AMPS to protect against a short circuit.

One more thing, in the solenoid selection process DO NOT accept a solenoid with the control terminals marked in raised letters, such as 'S' and 'I'. This is a solenoid for ignition systems that run on 6Vs (old Chevy/GM pre 1974)and needs a ballast resistor in the circuit. This is NOT a power control solenoid, but rather a starter solenoid and is rated intermittent duty. It will fail with in two hours of installation.

If you or the salesman are unsure about the rating (constant duty or intermittent duty) of the solenoid, just run an Ohm meter across the control terminals (small ones). Anything over 10 Ohms is intermittent duty and should be rejected. The lower the Ohm meter reading, the better.

Now you can haul ass all day and arrive at your new destination in the evening and be all ready for Sunday Night Football on the Plasma screen TV.

The Deuceman
__________________
DubleDeuce is offline   Reply With Quote
Old 10-03-2009, 05:14 PM   #21
1 Rivet Member
 
DubleDeuce's Avatar
 
1982 31' Airstream310
Lilburn , Georgia
Join Date: May 2009
Posts: 17
In the last post I recommended installing a constant duty solenoid but gave no recommendation as to what to buy The Cole Hersee Co of Boston, MA sells a compatible unit, P/N 24812. It is a heavy duty unit designed for constant duty use and the company makes excellant products. Dealers can be found in many cities under the guise of heavy duty truck parts outlets and distributors. If they don't stock it they can get it.

http://www.colehersee.com/pdf/H-Relays.pdf

The Deuceman
__________________
DubleDeuce is offline   Reply With Quote
Old 10-03-2009, 07:14 PM   #22
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,813
Images: 12
DubleDuece

In your charging description you do not account for what controls the alternator. It is my impression that once the regulator in the alternator see a charged battery it will cut back on the charge rate. If the TV batteries reach a full charge and the alternator cuts back what good is this system.

On the other side I have had a condition where having run around all day without the trailer and many starts of the TV during the day without sufficient time recharge the TV batteries. The following day with a fully charge set of trailer batteries the TV batteries were dead after the second or third start that day. I had always figured the alternator was seeing the fully charged trailer batteries and thus had cut back on the charge rate.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 10-04-2009, 10:22 AM   #23
Rivet Master
 
2005 19' Safari
GLENDALE , AZ
Join Date: Aug 2004
Posts: 2,441
By the way, Optima (and I am sure other manufacturers) make some batteries that seem to share both starter and deep-cycle characteristics. I would guess that these would work in boats and motorhomes, which may need a battery (or batteries) that can do both.

I am sure this is a compromise, and probably doesn't work as well as two dedicated systems (one for the engine, and one or more to power the RV appliances and electronics), but these are available. Check out the Optima Yellow-Top series.
__________________
Phoenix is offline   Reply With Quote
Old 10-05-2009, 12:28 PM   #24
2003 26' Land Yacht-"Bud"
 
magwa's Avatar
 
coarsegold , California
Join Date: Jul 2009
Posts: 24
My Mistake

DD: "You did not mention the towing vehicle make or model."

Aaaaah! I wasn't very clear.

I was hoping to figure out how to charge the new stand-alone system from the MH alternator.

I'm (only) pretty sure it charges the in-place "house battery" system now as I drive. But I'd like to have it charge both, as I intend to tow the Jeep only from time-to-time.

__________________
magwa is offline   Reply With Quote
Old 10-05-2009, 09:32 PM   #25
1 Rivet Member
 
DubleDeuce's Avatar
 
1982 31' Airstream310
Lilburn , Georgia
Join Date: May 2009
Posts: 17
For Howie,

<<once the regulator in the alternator see a charged battery it will cut back on the charge rate.>>

This essentially true...IF all of the batteries, house and towing vehicle, are hooked up in a locked parallel condition. The "solenoid"" I spoke of above prevents this condition from happening. As a for instance, if the MH vehicle has a low charge condition, the alternator will see, through the solenoid, that low terminal voltage and the alternator will continue to charge until both sets of batteries are equal.

I have seen MANY instantces of complaints about batteries not charging properly. The scenario that you present <<I have had a condition where having run around all day without the trailer and many starts of the TV during the day without sufficient time recharge the TV batteries.>> appears to be one of a failing tow vehicle battery. (unable to take and hold a full charge). If the system is hooked to a solenoid as described above (NOT a solid state battery isolator) you can be certain that both batteries will receive the proper and full charge.

As a point to consider, I have, over the years, seen many a misdiagnosis of a customer's vehicle charging system. The most common repair made in these instances of misdiagnosis has been to replace the battery with a new one. The great thing about this approach is that it demonstrates to the customer that his/her car will now start AND it is quite profitable. The downside to this kind of slam/bang repair is that the car will be back in 3-4 days time. It takes about 3-4 days of AVERAGE driving for a new battery to be exhausted to the point of failing to start the car. This is when you get to see the customer again.

In your case, having run around all day, is not sufficient time to run a good condition battery down to the point of failing to start the engine. Odds are that the battery is on its last leg and you would do well to replace it now.

Another STRANGE occurance (as far as the customer is concerned) is the sudden and total colaspe of the vehicle battery without warning. The scenario goes something like this; battery is well into 80% of its usable life, customer lives/works some 10-15 miles from work and heads home intoa rain storm or snow. The driving is slow and all electrical systems are on. Heater motor trying to keep the windshield clear of ice, windshield wipers going full blast, headlights on, and stop and go traffic. Other than the serious threat of accident due to the roads and traffic, all is well that ends well as the wife gets home, relieved of the ordeal. the next morning the temperture drops to maybe 35-40 degrees as a front has moved in. She goes out to start the car and WHAT? Click, click, click.

What happened? the car was working perfectly last night.

What actually happened was the battery died. Pure and simple. What is not so easy to understand is WHY the car performed so well the hight before.

That is a simple answer as any of you who have seen this before can attest to. The battery was perfectly capable of starting the car the day before as the weather was warm and mild. Most any 97 lb weakling can start a car in this condition. On the way home the use of all of the electrical appliances coupled with the slow vehicle speed conspired to draw down the terminal voltage of the battery by taking out more electricity than was being put in. The alternator is often a suspect in these situations but as often as not, it is not true. The battery is now put away for the night with only maybe 10-15% of its "rated" capability due to the excess drawdown.

In the morning, the temperature drops to 35 degrees, and according to the laws of physics, WHATEVER amount of electrical current that was present in the battery when the car was shut down, is now cut in HALF. This is true EVEN for a BRAND NEW BATTERY. 1/2 of 15% of almost nothing equals that anoying click, click, click.

Get one of them new "Bunny Batteries" with a Hot Pink case.

The Deuceman
__________________
DubleDeuce is offline   Reply With Quote
Old 10-06-2009, 08:39 AM   #26
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,813
Images: 12
Quote:
Originally Posted by DubleDeuce View Post
For Howie,

<<once the regulator in the alternator see a charged battery it will cut back on the charge rate.>>

This essentially true...IF all of the batteries, house and towing vehicle, are hooked up in a locked parallel condition. The "solenoid"" I spoke of above prevents this condition from happening. As a for instance, if the MH vehicle has a low charge condition, the alternator will see, through the solenoid, that low terminal voltage and the alternator will continue to charge until both sets of batteries are equal.
I think I would have to see a diagram of your solenoid installation to see how it isolates the 2 sets of batteries from the above condition.

Years ago I considered a system of switching transistors to switch between the 2 sets of batteries at a very high cyclic rate, The transistors were just out of the question price wise do to the size.

Yes the isolation diode system, sold for years, can not work because of the .7 volt drop across the diode.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 11-23-2009, 10:32 PM   #27
Streamline Imperial
 
SilvrSausage's Avatar
 
Currently Looking...
Bellflower , California
Join Date: Jan 2007
Posts: 109
Post

Isolation diode system works fine when your regulator senses battery voltage rather than alternator voltage. Depending on the type of tow vehicle, this may be easy or hard to design in to your system.

Plus, isolators are easy to cascade for multiple battery banks.
__________________
It seems I love the mountains and deserts more than my friends do. I sure miss them!

1971 Streamline Imperial project "Silver Snausage", 1985 Coleman tent trailer, 1964 Little Dipper, 1975 Northwest "Proto Toyhauler", 2004 Harbor Freight folding, still seeking my Airstream.
SilvrSausage is offline   Reply With Quote
Old 11-24-2009, 10:03 AM   #28
Liberator
 
klattu's Avatar
 
1972 Argosy 24
1989 34.5' Airstream 345
Heart of Dixie , Alabama
Join Date: Sep 2006
Posts: 1,646
Images: 834
Too much information
__________________

__________________
Your opinion is valued, please not your opinion of someones else's opinion.
Click To See Me Wet
1989 Airstream 345 Liberator...
1972 Argosy 24'...
1954 Feathercraft Vagabond
klattu is offline   Reply With Quote
Reply

Tags
12 volt, 12v


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
12 Volt Golf Cart Batteries? Phantom Batteries, Univolts, Converters & Inverters 20 11-28-2007 07:29 PM
New Lifeline 6 Volt Batteries lewster Batteries, Univolts, Converters & Inverters 0 04-22-2007 07:24 PM
Can I Replace 12v light with AC fixture and still work off 12v M&M CAPECOD Electrical - Systems, Generators, Batteries & Solar 5 07-11-2005 11:58 AM
Two 6 volt batteries on International AS nayl 2002 - 2005 International 9 03-24-2005 09:23 PM
Wiring Sequence to hook up 2 x 6 volt battery pack to your 12 volt trailer battery TobyJH Batteries, Univolts, Converters & Inverters 0 05-21-2004 01:04 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:00 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.