42 replies to this topic

[JaSAn]

Wire size, depending on year of manufacture, is a great question for Stan ...Stalking Light..you have a single panel @ 100w...would the current 160w panel be sufficient to keep the batteries up to snuff, assuming sunshine of course.

 

My head is spinning with all the solid info in this thread...Question:  How would a FWC owner know if the alternator is providing enough current to charge a pair of batteries in the camper?  Run the batteries down on voltage and then see if that is restored?

 

Thanks...

 

Phil

 

200W solar, 208ah batteries running a 2.1 cu. ft. refrigerator, fan, LED lights, charging MacBook and iPhone.  I am usually back to 100% by 11 AM.  Only once this last year was I not back to full by end of day and that was in 90+F temps with heavy overcast.  So far I have not even hooked up charging from the truck.

 

Quickest way to test charging is to run the battery down below 80%, start truck charging and use a volt meter and clamp on ammeter to see what is happening at the battery.

 

Question for the electrical gurus:  If my solar charge controller is providing 15 amps at 14.5 volts and my truck is providing 60 amps at 13.5 volts (at battery), does the alternator current help charge the battery?

 

jim

[wuck]

Question for the electrical gurus:  If my solar charge controller is providing 15 amps at 14.5 volts and my truck is providing 60 amps at 13.5 volts (at battery), does the alternator current help charge the battery?

 

jim

 

No. Simply speaking, current will flow from a given voltage towards a lower voltage. Now, if the camper connection was at the alternator instead of the truck battery, and the alternator voltage output was more than 14.5 volts, and there was no drop in the wiring or separator, then it would contribute. That's why a short, fat connection is best.

[K7MDL]

Marker lights on my 2014 Hawk are apparently driven directly by truck circuit via the third wire in the Marinco connector rather than by camper battery.

Paul

I ran the 3rd wire up to my engine compartment fuse holder to a fuse that was ignition switched using an add-a-circuit fuse tap.  At 0.5A pretty much any circuit can handle it.  That means the marker lights are on all the time the truck is running, but I was in a hurry.  Ideally I would track down the trailer tail light wiring and see if that will work.  In the 2016 F150 the trailer power is switched by relays and I have not verified if 0.5A will be enough to trigger the trailer power relay on.  The truck detects each lamp and warns of a bad bulb/connection on the dashboard.  It also trigger trailer configuration profiles for brake effort, miles towed, and backup assist pro feature.

Edited by K7MDL, 15 May 2016 - 11:49 PM.

[DannyB1954]

DannyB, do you have more than one of those relays in parallel? They're only rated for 30 amps normally.

 

I like the right Voltage Sensing Relay (VSR) or Automatic Charge Relay (ACR) because they won't close and connect the camper battery until the starting battery(ies) have been recharged. Searching either of those two names should pull up the many discussions that have been had here about them.

 

I don't own one, yet, but this is my ideal battery charger: http://www.amazon.co...d=I1LW6VAW7Y7TI Takes the place of BOTH the isolator/relay and the solar charge controller. Treats the alternator's output as another charge source like a solar panel, picks the better power source, and applies the same charging logic to the camper battery(ies) regardless of the source.

You can buy the 5 pack and put them all in parallel. As Dynobob said in post #7 there may be a spare relay already in the vehicle. Or you can find a relay that you would rather use. If you do use more than one relay, how would you ever know it if one of them were to fail? It would probably have zero effect. The relays are rated for 40 amp. I don't think that charge rate happens in my application. You could use a 30 amp auto reset breaker to make sure that you did not overload the relay, but I have not had any problems. 

[bfh4n]

Vic,

 

The CTEK D250S alone is rated at 20 Amps but in combination with the SMARTPASS, the rating is 80 Amps. Either way, the 20A rating applies to the MPPT solar charger aspect of the D250S.

 

Again, I haven't used mine enough to verify these numbers. I've installed a Trimetric monitor, so I should have some good data eventually...

 

- Bernard

[ntsqd]

You can buy the 5 pack and put them all in parallel. As Dynobob said in post #7 there may be a spare relay already in the vehicle. Or you can find a relay that you would rather use. If you do use more than one relay, how would you ever know it if one of them were to fail? It would probably have zero effect. The relays are rated for 40 amp. I don't think that charge rate happens in my application. You could use a 30 amp auto reset breaker to make sure that you did not overload the relay, but I have not had any problems. 

If you are charging above 30A and one of let's say two paralleled relays did fail the other would be exceeding it's rating. How it would fail would be speculation, but that it would fail is almost certain. Perhaps not right away because there is some Factor of Safety built into them, but eventually.

I agree, charging over 30A is likely not a common thing. Possible though, and that was my concern.

[Vic Harder]

Vic,

 

The CTEK D250S alone is rated at 20 Amps but in combination with the SMARTPASS, the rating is 80 Amps. Either way, the 20A rating applies to the MPPT solar charger aspect of the D250S.

 

Again, I haven't used mine enough to verify these numbers. I've installed a Trimetric monitor, so I should have some good data eventually...

 

- Bernard

Ah, all good then.

[DYNOBOB]

Again... Thanks to the OP for starting this thread!  We're leaving shortly for a 4 week run to Alaska and this could have bit us in the butt (the house battery not charging while driving because we ran it below the isolater cut out threshold).  In case this situation rears it's head, I've wired a manual 60a switch that bypasses the isolater.  It's hidden behind the access panel and in a minute I can pull the panel and get the house battery charging again.  I have a handy little meter that plugs into the cig lighter and show where the house battery is.

 

 

 

 

 

If I knew six months ago (when I was wiring the truck to camper) what I know now, I'd have done things differently.  It concerns me that FWC only provided one 10ga power and ground to run the camper while there are four unused pins in the camper plug.  I could have run three 10ga grounds and three 10ga hot wires to the battery and still had an easy plug/unplug arrangement with three times as much wire/connector pins to carry the power.

 

 

 

Not having the time or energy to pull the camper and start from scratch, I opted to use the 10ga ground that runs thru the camper plug to the truck battery as a second power wire.  For ground I dropped two 10ga wires from the buss bar directly to the truck frame.  There are now two 30a power feeds from the truck charging system.  I feel 100% better about this arrangement.

 

 

 

.

Edited by DYNOBOB, 13 July 2016 - 11:14 PM.

[rubberlegs]

Speaking of relays and isolators... we just got a Fleet on our Tacoma. I notice when I turn on the accessories, but don't fire up the engine, I get a warning on the dashboard. (I do this to listen to the radio or check mileage, etc.). This doesn't appear when the engine is started (and the alternator is working). So I think the camper battery and truck battery are connected, which the truck "doesn't like". Sorry, I forget the exact message.

 

The question is: we shouldn't use accessories very long, because the batteries will take power from each other? Sound right?

[Vic Harder]

Speaking of relays and isolators... we just got a Fleet on our Tacoma. I notice when I turn on the accessories, but don't fire up the engine, I get a warning on the dashboard. (I do this to listen to the radio or check mileage, etc.). This doesn't appear when the engine is started (and the alternator is working). So I think the camper battery and truck battery are connected, which the truck "doesn't like". Sorry, I forget the exact message.

 

The question is: we shouldn't use accessories very long, because the batteries will take power from each other? Sound right?

This does not sound right.  The isolator should isolate the two systems - Truck and Camper - unless there is power coming in either via the alternator or via the solar panels.

 

Depending on the isolator capabilities and wiring, one of these systems is the "home" system and other the accessory/house/camper system.  Using the truck as HOME, once the engine is running and alternator spinning, the isolator uses a voltage sensing system to check if it is safe to connect the two, to share the power coming in to charge the other system as well.  Before that, there should be no connection and the truck should be unaware of the camper.  

 

As for not using accessories long, are you talking truck or camper accessories?  If camper, then the isolator should separate the truck from the camper batteries when the voltage drops, thus protecting the truck/starter batteries.