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DubleDeuce · 10-03-2009, 04:14 PM

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

HowieE · 10-03-2009, 06:14 PM

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.

Phoenix · 10-04-2009, 09:22 AM

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.

magwa · 10-05-2009, 11:28 AM

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.

DubleDeuce · 10-05-2009, 08:32 PM

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

HowieE · 10-06-2009, 07:39 AM

Quote:

Originally Posted by DubleDeuce

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.

SilvrSausage · 11-23-2009, 09:32 PM

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.

klattu · 11-24-2009, 09:03 AM

Too much information

Gator113 · 04-20-2010, 05:55 PM

"Saturday I bought two Golf Cart batteries from Costco for only $75 each. I'll give them a try but friends say they are just as good (and heavy) as the Trojan T105s."

How did that work out for you? I am a rookie with AS and I bought my first 20 days ago, 2007 25' Classic-limited. I will soon be upgrading the batteries, so I am trying to determine the best way to go.

mello mike · 04-20-2010, 06:46 PM

Quote:

Originally Posted by Gator113244

"Saturday I bought two Golf Cart batteries from Costco for only $75 each. I'll give them a try but friends say they are just as good (and heavy) as the Trojan T105s."

How did that work out for you? I am a rookie with AS and I bought my first 20 days ago, 2007 25' Classic-limited. I will soon be upgrading the batteries, so I am trying to determine the best way to go.

A good and timely question. For several years I've used 6v golf cart batteries and loved them and never had any problem with them at all (see my earlier post in this thread). That was until last weekend. Saturday evening the (-) negative battery post separated from the battery while charging and it killed all the 12v power to my Sovereign.

Boy that really sucked!!!!

So the moral of the story is if you only have room for two batteries go with 2 12v Size 27 batteries. If you have room for four go with 4 6v batteries (the likelyhood of two batteries failing is astronomically small). I returned both 6v batteries to Costco and got two 12v Size 27 batteries instead.

Gator113 · 04-20-2010, 11:17 PM

Thanks for responding so quickly, Mike. The batteries are 3 years old and don't seem to hold a charge very long , so rather than have a bad camping trip, I'll replace them now. I don't really have room for 4, so I will likely stay with the 2 12v.

I have a Honda 2000i and I intend to get a second, so I think I'll be covered.

Thanks again,

Dan

mortond · 04-21-2010, 10:07 AM

Hi,
For what it's worth: I have just purchased (5) 115 AH, 600 CCA, 750MCA deep cycle batteries from Concord, CA Costco. They cost $67.50 each plus $9 core charge.
I shall use one as a SLI battery and 4 as house batteries. I am removing the Airstream supplied battery combiner (it's nearly as old as me) and replacing it with a Blue Seas 'Add-a-battery' setup. The five batteries will all be connected together during charging: shore power battery charger, alternator, generator charger.
Whilst connected to shore power I shall use all five as house batteries. If shore power is disconnected I shall switch to isolate the SLI battery from house discharge (but not charging)
Next financial stage is to install four solar panels (AM100-m's) and a Blue Sky MPPT solar panel controller and battery monitor control unit.

When purchasing batteries insist on getting the current months production units.
I was told my Costco restocks on Thursday that's when I went there.
Batteries self discharge when filled (wet) so sitting on a store shelf depletes the useful life, they are not usually charged in any way by the stores.
I used these same batteries on my houseboat and had no problems with them.
As battery making is a nasty business and the EPA is active (for once) there are only 4 or 5 manufactures in the US so labeling doesn't mean too much. Costco's brand is Kirkland. They have a vested interest in not selling crap soooo!

Hope this is of some interest

David
1989 36' Land Yacht

rustyrivet · 04-21-2010, 10:43 AM

When I got my Honda 2000i, there was a warning in the instruction book about using it to charge deep cell batteries. Something about charging too quickly and possibly over-charging and damaging the batteries. I contacted Lifeline (the maker of my batteries) and they told me that their batteries would accept the quicker charge without a problem. Has anyone else seen the warning in the Honda 2000i booklet? jc

mello mike · 04-21-2010, 01:29 PM

Quote:

Originally Posted by Gator113244

Thanks for responding so quickly, Mike. The batteries are 3 years old and don't seem to hold a charge very long , so rather than have a bad camping trip, I'll replace them now. I don't really have room for 4, so I will likely stay with the 2 12v.

I have a Honda 2000i and I intend to get a second, so I think I'll be covered.

Thanks again,

Dan

Dan,
One Honda 2000 is more than enough to charge your batteries. Unless you intend to use the pair to run your air conditioner.

kmpro · 04-21-2010, 03:35 PM

Good thoughts in this thread guys. Just remember, anytime you are buying a battery it is like buying a Banana. Life is limited at best.
when a post separates off, something besides age causes that. Stress on the cable, excessive vibration or tension, could be a number of things. I have found waay too many side -post batteries ruined by over-tightening the cable bolts. 7 lbsFt torque is plenty. On top-post units proper cleaning and tightening of cables is important too. Most of all, CHECK the electrolyte level once monthly. If needed, add distilled or RO water only! A healthy battery uses 1oz of water per cell per month. At least that is what Electric Storage Battery Co says. Keep the top of the battery clean and dry to minimize leakage of the charge. Treat it like a Banana. Care for it, and clean and protect it. Makes 'em last. My last 4 6V house batteries were 7 years old and still going strong when I sold the unit.
Mike

mello mike · 04-21-2010, 04:27 PM

Quote:

Originally Posted by kmpro

When a post separates off, something besides age causes that. Stress on the cable, excessive vibration or tension, could be a number of things. I have found waay too many side -post batteries ruined by over-tightening the cable bolts. 7 lbsFt torque is plenty. On top-post units proper cleaning and tightening of cables is important too... My last 4 6V house batteries were 7 years old and still going strong when I sold the unit.
Mike

Good points, Mike. I'm sure that stress and tension were the culprits in my recent 6v battery failure. I recently installed a Xantrex Freedom 10 Inverter-Charger and I opted to install the big 2/0 cables. I'm sure there was a lot of tension from these cables that caused the failure. I really loved using the 6v batteries, but this recent failure made it clear that if you only have room for two batteries, go with the 12v Size 27s (If I had room for four I'd go with 6v batteries any day). Having no 12v power (no lights, water, and refrigerator) really sucked the last day of our trip.

kmpro · 04-21-2010, 11:09 PM

Roger that Mike. When the frige goes out, it's all over with me. Don't blame you for the change either. I'm trying to engineer a way to successfully fit in 4 6V batteries on my Silver Hornet. Looks like a major overhaul of the battery tray along with a real-world converter/charger for my rig.
Mike

Gator113 · 04-22-2010, 11:50 PM

Quote:

Originally Posted by mello mike

Dan,
One Honda 2000 is more than enough to charge your batteries. Unless you intend to use the pair to run your air conditioner.

Yes Mike. Locally, I should seldom need an air conditioner, but should we dry camp someplace hot, I require it in order to breath without difficulty. I don't like spending the money on another one, but for me, it's better safe than sorry.

I also have an oxygen concentrator and a C-PAP that I require for sleeping, so I need dependable power. It's a pain, but I've learned to just work around the issues as they come up. ;>)

Now if I could just get my hands on a portable nuclear reactor....