Charging battery from TV & generator ?’s

[bmklawt]

My TV is a 2005 Silverado, it is my understanding that when the battery is charged the alternator drops the current below charging level. If this is the case how do I charge my trailer battery when towing or is my Inteli power 9200 series converter doing the charging, is the 12 volt power at the trailer plug independent of the charge system on the truck. I’m confused.

Second question is there a 120 volt generator that can be mounted directly to the engine in my truck. I like the idea of having the generator permanently attached to the truck as appose to lugging a separate generator around. I would like to be able to use this to power the house in the event of a power outage also.
I know I can put an inverter in but isn’t a generator more efficient.

[HowieE]

The cost and the space required just about cuts out the generator in the truck. You could mount an inverter that would give you 120 but there are limits there.

Yes the alternate will drop back as soon as the voltage to the field is up thus halting the high charge rate generally put out after stating the truck. Now while on the road and any load is put on the truck battery the charge rate will go up again and all batteries will benefit with the trailer batteries getting a lower rate because of voltage loss in the length of the wires to the trailer.

About the only way to guarantee you are charging the trailer battery wile driving would be to install a second alternator and have it wired so it only sees the trailer batteries.

Do not get sold on a so called trailer battery Isolator. There is a diode in all of them and the voltage drop across a diode is .7 of a volt thus you are at a loss before you start, but Camper World has to make a buck some how.

[boondockdad]

There are Power-Take-Off generators, but I can't imagine they'd be very cost effective without a diesel truck

[Finch]

what about running a invertor in the TV to run a battery charger in the trailer

[CanoeStream]

Originally Posted by Finch

what about running a invertor in the TV to run a battery charger in the trailer

Too many inefficiencies in this plan -- inverting to AC through small wires from cig lighter and converting back to DC. Length of the wiring runs would only compound the problem.

Alternator output has a variable and frequently fairly small excess of amps that it can spare for the umbilical. Allowing for a 50% discharged deep cycle coach battery (the most you'd want to discharge a lead-acid on a routine basis), word of mouth is that we shouldn't expect substantial coach battery recharge until a couple hundred or more miles have been driven. Results may vary depending on whether the alternator is being hit up to run headlights and air conditioning too.

[Jammer]

Originally Posted by HowieE

Do not get sold on a so called trailer battery Isolator. There is a diode in all of them and the voltage drop across a diode is .7 of a volt thus you are at a loss before you start, but Camper World has to make a buck some how.

This used to be true but isn't, necessarily, any more, though there are still cheap diode isolators out there. Avoid them.

There are two other kinds.

One uses a MOSFET or similar device to do the switching. These are semiconductors, but don't have an NP junction like a diode. No junction, no diode drop. The problem with them is that they are expensive and are easily damaged by overcurrent, and the ones that are big enough to handle a short long enough for the fuse to blow are really expensive.

The other kind uses a big relay, operated by logic of varying sophistication. The simplest of these close when the voltage goes up above 13.5 or so and open when it goes below 12.7. Others incorporate time delays to minimize nuisance cycling.