A basic 12V question - where should I put it?

[splyb]

We're replacing everything. Everything. In pondering the electrical system, some basic questions occur to me.

1) I've read that the batteries and converter should be as close to each other as possible. Something about voltage loss over long wires. Is that true?

2) If so, where should I put all this stuff? We're considering a converter > 50 amps and two deep discharge 6 volt batteries - the golf cart kind. Haven't decide Lithium or not but one thing seems certain: This grouping, assuming they have to be close together, will be SERIOUSLY heavy. Each battery could weigh > 100 pounds, right? My instincts tell me to put the whole mess over the axle, or as close as possible. But my observations are that most folks put them well to the rear and others well to the front.

What factors should we consider when trying to decide where to put these things?

Jay & Lisa

[switz]

In a perfect world, the battery and converter location would be over the axle. Airstream usually puts the battery(s) on the tongue in the battery box and the converter under the front bed.

No mention of solar, but the solar charger equipment is typically under ten pounds.

In our 23D, the 84 pound 300 amp-hour lithium battery (actually lighter then the two stock Interstate batteries) is immediately in front of the street side wheel well under the "sofa". The solar charge controller and switches are wall mounted just forward of the battery. The Magnum MSH-3012 inverter/converter is just in front of the furnace under the dinette seat with a new 30 amp main circuit breaker box and a real automatic transfer switch to allow power from the custom installed front power inlet or the standard rear one.

The front battery box is now storage for wheel wedges and base plates for the stabilizers.

One can get creative with a clean slate to work with.

[idroba]

The converter/charger and batteries don't have to be immediately adjacent, given a decent wire size between them. If you are planning on an Inverter, they really need to be pretty close to the batteries, if they are a high wattage variety. Wet cell 6 volt golf cart batteries weigh about 65 pounds each.

[splyb]

Thanks for those comments. I've no plans for an inverter (yet). I might try to put some of this stuff under the curbside gaucho which would let me get it over the axle - more or less. On the opposite side I'll have a fridge and furnace to balance side to side.

[switz]

To really know what you are working with, a weighing of the individual wheel weights now would form the basis for an informed decision on parts placements for any upgrade. I was surprised that the weight balance was off with one tire supporting about 100 pounds more than any of the other three.

While mechanical components will change over the years (typically getting smaller), planning ahead for the wiring and parts placement now will save lots of future relocation expenses. Installing the runs of wire for the future while the cabinetry is out is always a good idea.

If it takes five hours to remove and five hours put back the interior, that is a considerable expense at shop rates that could possibly be saved with good preplanning.

[splyb]

"A weighing of the individual wheel weights"? What's that?

[switz]

The trailer is taken to scales where the weight of the load on each tire is determined. That provides the necessary data to determine the minimum rated tire capacity (as printed on the sidewall of the tire) one needs to have a reserve load capacity so the tire is not carrying it's maximum rated payload on a continual basis.

For most trailers, when weighed, the report is the weight of the single, double or even triple axles being on one scale with the rear axle of the tow vehicle on another plate and the front axle on a third plate. The report gives front axle, rear axle, and trailer axle(s) and the total of the rig weights.

Averaging the trailer axle weights does not give the true story. One may find with the individual wheel weights report that one axle is carrying more weight than the other and or one side is heavier than the other. The owner can then ss if they can adjust the payload inside the trailer to balance the load.

In all three of our trailers, there has been one wheel that was carrying 100 to 150 pounds of more weight than the other three. That weight was related to the location of the shower in one, a battery system in another and cabinetry in the third. I set my minimum tire pressure so that the tire with the heaviest load had a good reserve capacity while still less than the maximum pressure on the sidewall of the tire.

I carry 44 psi in the 15" Michelins installed on the 23D and 72/73 psi in the 16" Michelins on the Classic. The Dill 1506-453 TPMS reports that the tire temperature and pressure rise when moving is within limits at these pressures.