Charging question.. just to make sure I understand correctly

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41Woodie

Charging question.. just to make sure I understand correctly

Post by 41Woodie »

if I turn the master disconnect beside the driver's seat to the off position can I connect the house batteries to a charger without harming anything. My concern is that the factory charger/converter is isolated from the batteries when the switch is off or does it matter.
The plan is to attach a Deltran Battery Tender to the house batteries and plug the Tender into shore power.
In addition if I add a 12v accessory plug to the Battery Tender could I simply attach the shore power to the coach, plug the tender into any wall socket in the coach and plug the Tender into the accessory plug, or do the dash mounted accessory plugs connect to the car battery only?
I just re-read the question and hope some of you make sense out of what I'm asking.lol
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whemme
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Joined: Mon Aug 15, 2005 8:05 pm

Post by whemme »

If you turn off that battery master disconnect switch, your house batteries are totally isolated and not connected to anything. So hooking a Deltran Battery Tender to the house batteries will not cause damage to anything.

The dash mounted 12 vdc cigarette lighter power sockets are connected only to the chassis battery and not to the house batteries. This is what you could do to keep your chassis battery charged while your coach is in storage. With the battery master switch off and with the coach plugged into shore line power, all 120 vac wall sockets in the coach are powered so you could plug the Deltran Battery Tender into one and then plug the 12 vdc output plug of it into one of the dash mounted coach mounted 12 vdc cigarette lighter power sockets to keep the chassis battery charged.

Or you could use the alligator clips that I assume the Deltran Battery Tender came equipped with and connect them to your isolated house battery terminals to keep them charged. You can't charge both your chassis and house batteries at the same time from a single Tender, you would need two of them to do that.
Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
41Woodie

Post by 41Woodie »

I'm assuming that it would be better for the house batteries to turn off the master disconnect, and charge with the Deltran rather than the charger/convertor when camping and connected to shore power for several days, correct?
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Mel Wilbur
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Joined: Thu Aug 11, 2005 2:39 pm

Post by Mel Wilbur »

Keep in mind that with the master switch in the off position when camping you have no lights, water pump or anything that utilizes 12 volts.
Mel & Connie
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whemme
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Joined: Mon Aug 15, 2005 8:05 pm

Post by whemme »

What Mel says is true but only when dry camping with no shore line power hookup. All DC powered appliances in the coach will run from the charger/converter with the battery master switch off if the coach is plugged into shore line power.

If plugged into shore line power for an extended period of time with the battery master switch on, once the house batteries reach full charge status any further charging will result in over-charging, slow boiling out of battery electrolyte and damage to the house batteries. This assuming that your coach is equipped like most with the original single-stage Parallax 7345 Charger/Converter. You can avoid this over-charging problem and not have to use a Tender battery charger if you want to consider changing out the Parallax 7345 for a modern 3-stage charger converter such as the Progressive Dynamics PD4655 Charger/Converter.

Refer to my post titled Converting Parallax 7345 Charger/Converter to PD4655 system in the Coach Modifications section on this website. Click this for a direct link to that post: http://www.bornfreervclub.org/bulletin_ ... php?t=2482
Last edited by whemme on Thu Aug 09, 2012 6:00 pm, edited 5 times in total.
Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
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Mel Wilbur
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Joined: Thu Aug 11, 2005 2:39 pm

Post by Mel Wilbur »

Bill, good catch, I forgot to add the words dry camping to my post. Thanks
Mel & Connie
41Woodie

Post by 41Woodie »

So to recap if I'm parked for several days and hooked to shore power it would be kinder to the house batteries to turn the master disconnect to off and hook up a battery tender to avoid over-charging and boiling the house batteries as could happen with the stock converter/charger.

I've just added a 12v accessory plug to the side of the battery enclosure. I added it to furnish a plugin for a 12v bilge pump that I'm using to pump water into the tanks from aqua-tainers when camping without a water supply. I could purchase a male 12v plug attachment for the battery tender and plug it in to the female to avoid using the clamps or hard-wiring that comes stock with the Deltran chargers. Or save up my pennies and purchase a modern 3-stage converter this winter.
Thanks for the info guys it's much appreciated to have another set of ears to make sure I'm correct before doing something that could lead to disaster.
Now to start saving up for some solar panels and necessary accesories for a winter project. MH
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whemme
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Post by whemme »

Actually, if you are parked for several days hooked up to shore line power, it would be good to shut off the house batteries master switch to prevent over-charging. However, I don't really think it necessary to hook up your Deltran tender battery charger to the house batteries for such a short stay of several days - they will not discharge any significant amount during a stay of several days.

Where you would want to use the battery tender would be when your coach is stored and inactive for a month or more at a time.
Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad
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