Born Free Leap'n Lions RV Club Info & Discussion Forum

Battery questions
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Author:  mi99amigo [ Thu Dec 29, 2005 11:28 pm ]
Post subject:  Battery questions

Hi all, since this is my first MH, I would like to ask a couple of questions to those who are more experienced.

1. I would like to hook up a trickle charger to my house batteries. Since they are hook up in paralell, do I simply hook the charger to same the terminals that the house cables are attached to? I would think that should charge up both batteries.

2. If I hook up the trickle charger and disconnet the house batteries by turning that big knob in the coach to the OFF position, can I then safely plug in shore power? I would think one should NOT plug in shore power AND charge the batteries with a separate charger at the same time, right?

Thanks for your help!

Author:  Dave&JanPotter [ Fri Dec 30, 2005 12:12 am ]
Post subject: 

You are right about hooking up the external charger as it will charge both house batteries if they are in parallel....just connect positive to positive and ground to ground as you would with one battery. I use a separate length of #10 wire on the ground terminal(s) so that I can disconnect the charger, when I'm done, in a location slightly removed from the battery and avoid any chance of a spark in the vicinity of the battery. Unsealed batteries give off Hydrogen gas which is highly explosive, when charging and batteries should not be charged in an unventilated space or where there is any chance of a spark. You also mentioned using a trickle charger however and this can lead to problems. Trickle chargers have been around a long time and there are many different types. What is commonly called a tickle charger keeps a small current flowing all the time to the battery, constantly charging it. This constant current can boil a battery dry if the water/acid level is not checked and replenished regularly. It is much better to use one of the solid state three stage chargers which effectively shut themselves off when the batterie(s) are charged, thus avoiding boiling them dry. As for disconnecting the batteries from the house circuits (using the disconnect switch) when you charge them using a separate charger, this is a good idea. Many of the solid state chargers sold today have a cycle that comes on automatically whereby a higher voltage is applied to the battery for a period to undo some of the deposits that build up on the plates inside, thus increasing battery life. Not all chargers do it but many of them do so it pays to check it out. As this cycle is automatic, you can't control it and might not want it on the bus of your house system where it might get throught to the circuit boards in your H/W heater, furnace or refer and damage them. Opening the battery disconnect switch while charging with one of these chargers should prevent any possibility of a backfeed like that. I do it all the time with mine and don't have a problem You didn't say what kind of converter you have, some have a solid state battery charging feature built in and some do not. If you have the Parallax Model 7345 that many of us have as OE, it provides a constant 13.8 vdc and will boil your batteries dry if they are not checked/refilled. It is not a three stage charger and either changin it out or using the separate charger as you suggested is a good idea. A search of this forum should give you an excellent write up by Bill Hemme of how he made that changeout. Many others have done it successfully using his guide.

Author:  whemme [ Fri Dec 30, 2005 1:06 am ]
Post subject:  Trickle Charger


If you want to use a trickle charger to keep your coach batteries charged during long periods of storage but not over-charge them and boil the water out of your batteries, then I would recommend the Battery Minder. Check the product out at this factory website address:

You can order it from the factory for $59.95 I believe or you can currently order it from Camping World at a cost I believe of $44.99. Refer to Camping World website address:

If you want to change out your existing Magnetek/Parallax 7345 single stage charger/converter for a very good Progressive/Dynamics PD9160A 3-stage charger/converter that you can use to keep your coach batteries fully charged by just plugging your coach into shore line power, then you should consider this conversion. I have a detailed procedure referred to above by Dave & Jan Potter at this website address:

Author:  mi99amigo [ Fri Dec 30, 2005 9:04 am ]
Post subject:  Battery uestions

Thanks for the wonderfully detailed replies!

Yes, I still have the OE converter from BF and understands the limitations, that is why I wiill be using the outboard Battery Tender 3 stage charger. I will disconnect the batteries from the coach by the house shut off switch. The Battery Tender does come with a semi-permanent cable with a quick disconnect.

Sounds like once I isolated the batteries from the coach, I can safely plug into shore power and charge the batteries at the same time.


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