Diodes, Dudes!

[Bill Abbay]

I also wanted to reexamine the whole "charging the trailer battery from the tow vehicle" topic. I'm still not persuaded that raw amp-hours are returned to the trailer battery in any volume. Some capacity may be returned but not much.

...And that's it in a nutshell. While diode isolators prevent unwanted discharging, they also prevent any sort of proportional charging, as does, for that matter, any direct wired with-or-without-relay system. I've driven 300 miles assuming my 145 amp alternator was charging my trailer battery that was down only 10 or 15 AH from the previous night, only to find it was still down

An intermediate module that senses the condition of both batteries and proportions the alternator output according to discharge state needs to be inserted into the circuit. I think this is the creature.

[Steve L.]

That device looks "sweet" as the kids would say.

If I were running the company, that would be among the parts of the world class trailer tow package I would offer. Class III/IV hitch, 7 pin connector (It needs to be far enough away from the receiver to allow use of after market pin locks. Mine isn't.), brake controller, this separator. What else I wonder?

[Darwin Maring]

Just put a small windmill generator on the EGG and let it charge the battery while U R driving.

[Mike Taylor]

I don't worry about isolators or relays as I never hooked up a charge line to my trailer. I have 3- 15watt solar panels on the roof of trailer going to a solar charge controler and the battery is always full at end of day whether I'm driving or camped boondocked for a week. Theres still room on the roof for a couple more panels if I need more charge power but the controler usually shuts off about mid-day so everything is fine now. Mike

[Brian B-P]

Windmill? While we're thinking "out of the box" (and not really seriously)...

The wind thing seems a little indirect to me. Why not power an alternator or two from the trailer wheels, to make power from the towing action without an electrical hookup to the tug - just like the old bicycle headlight generators! Fiber Stream owners could put in four of them for lots of redundancy.

[Darwin Maring]

The wheel thing would work really well and put out more power.
Windmills are readily available because they use them on sailboats.

Just think, put a solar collector, windmill, water wheel, and wheel generator on the thing and you would have power rain or shine, day or night.

Weld the front end of a front wheel drive electric car to the front of the EGG and have a completely self contained, green, camper able to go anywhere at a moment's notice.

[Rob S.]

At one pint before I tore my trailer apart for resoration and I had a different tow vehicle I used a Battery Cut Off Switch. Inside the trailer I just turned the key and I was cut off from the tow vehicle without having to unplug. I seemed to work pretty well and allowed for the occasional tie in to the vehicle battery when amps were low at the end of the trip.
There are many types but this is the one I used. Cost was about $14 US, much cheaper than isolators.
http://store1.yimg.com/I/yhst-953602...69_1849_613774