Charging while towing

[4x4chvy]

The CTEK DUAL is now available in the USA. Took me awhile to find a vendor who would admit they had any, but with the help of CTEKs North American representative - success.
I realize most of you plug into AC power but for those who don't, you may want to check out the CTEK D250s DUAL.
It's a DC to DC charger which charges from both alternator AND Solar
http://www.ctek.com/EN-AU/dcdc/d250s-dual.aspx
Simple explanation video here:
http://www.youtube.com/watch?v=LPtawOngxWA
Best price I found with free shipping:
http://www.etrailer.com/Battery-Charger ... D250S.html
They're a Certified, Approved Ctek vendor.

Hope this helps someone.

[Shadow Catcher]

On top of the regulating the altermnator voltage to a multistage charger it is also an MPPT solar regulator. It is tempriture compensated and quite frankly I wish I had encounterd this a while back.
The manual http://www.ctek.com/files/manual/D250S-Dual_uk.pdf
The disadvantages I see is that it has a max solar panel voltage of 22V a fixed 14.4V (some deep cycle batteries need 14.8V to charge fully) and there is no adjustability for line loss.

[eamarquardt]

I'm not sure what advantages this thing offers. Seems like you could get the same functionality from a single pole double throw switch (to switch between the solar panels and alternator as a charge source) and a solar panel charge controller for half the cost. Of course you'd have to flip the switch on occasion but it would be easy to remember as you disconnect your trailer from the tow vehicle.

There you have it again, "The world according to Gus".

Cheers,

Gus

[Shadow Catcher]

Gus ya really gotta look at the manual.
This thing balances all the inputs, solar and alternator to get proper charge to vehicle and trailer battery.

[bdosborn]

it has a max solar panel voltage of 22V

I wouldn't be able to use this controller as my Kyocera PV panel has an open circuit voltage of 22.1V at standard test conditions, and I think this is a fairly common value. It would *probably* be okay but I think the NEC requires 25% headroom on the charge controller as there are certain conditions (cold day with snow on the ground) where you can exceed the Voc at STC. It's an interesting idea to use the MPPT section of the controller to boost the alternator voltage but I think an upsized charge wire on the TV and trailer will do the same thing.

I think most people have trouble charging their trailer batteries because the charge wire on most factory tow packages is way too small. My truck with the factory trailer package had a 14# charge wire and I had all kinds off trouble trying to charge the battery and run an RV fridge (10 amps). I was seeing 12.6v at the trailer battery and was actually draining the battery as I drove (luckily the PV panel was picking up the difference). I finally figured out what was going on and upsized the truck charge wire to a #6. Now I'm seeing around 13.8v with the fridge running. Not the best but it's charging the battery a little now.

Bruce

[eamarquardt]

Gus ya really gotta look at the manual.
This thing balances all the inputs, solar and alternator to get proper charge to vehicle and trailer battery.

I looked at the manual and got confused with the complexity (I drove over 300 miles today, took about 37.5 mg of Nucynta, and am tired so I'm not firing on all cylinders tonight). There is the D250S Dual and the Smart pass. Not sure why you need all this stuff.

I've never had a problem with any car's alternator not keeping the starting battery charged when the system is intact. I'm not sure why one would need to use a solar panel to charge the starting battery in your tow vehicle. IMHO it's not a good idea to use your starting battery for powering a trailer (just as I never used my reserve starting batteries to power the systems on our sloop when away from the dock) as it is not a deep cycle, not intended for extended draw down, and it's nice to be on the safe side and keep it separate from the trailer's power needs. So I'd just leave well enough alone and not modify the charging circuit for the tow vehicle's starting battery.

I think that if your trailer is connected to your tow vehicle your alternator will do a sufficient job of charging the "house battery" and any auxillary charging systems (solar, wind, generator, fuel cell, cow dung converter, beryllium spheres, flux capacitors, etc.) could/should be disconnected w/o any loss of charging capability. A car's alternator will put out far more than most solar set ups.

When you disconnect your trailer from the tow vehicle you flip a single pole double throw switch to connect any auxillary charging systems that you have to your "house battery". The auxillary charging system should its own dedicated "regulator" or "controller" tailored to the auxillary charging systems voltage and current.

I think what I've outlined above would be consistant with the KISS principle and be cost effective to boot.

Cheers,

Gus

[Kharn]

How does charging-while-towing interact with something like a Power Dynamics Intelli-power 4000? Would the power center and the charging wire from the TV both connect to the battery's terminals, or would you need a DPDT switch?

[PcHistorian]

@kharn Power Dynamics Intelli-power 4000 is a charger/converter from 110vac and SHOULD think that the battery is charged and do nothing while driving (no external 110vac connected while driving.)

Personally I like the "Isolator" idea. It keeps the two batteries separated when the TV is not running and charges what needs to be charged when running.

1.
That being said... (here's where everyone gets some BIG laughs.) I once went the route of connecting a second battery through a switch and 10ga wire. When I went to start the car I got many feet of 10ga wire with no insulation. Reason being, the car tried to start drawing from the spare battery. SO, 40 amp, self resetting breaker, sounds FANTASTIC to prevent that.

2.
I found that a second battery connected through from the first battery, had the first battery drop the voltage too much to get a charge on the second battery after going through the intervening wiring also. The resolution was to connect the power flow for the second battery to the source where the first battery got it, the wire from the alternator, at the alternator or close to it and not the battery itself. (for the positive wire.) This worked great as then both batteries had some drop from the charging wiring and the average of both batteries is what the alternator/regulator got to adjust from/for. (that's why the isolator should be in the wiring from the alternator output wire.

3.
What IDIOT(!!!!!) ALLOWED SOME ELECTRICAL MORON(!!!!!!!!!!) to plan the wire color scheme for the 7 wire connector, where the 12vdc positive is the BLACK wire and the red wire is now a turn signal color?!?!?!?!?!

How about WE vote to keep the yellow, green, brown, white of the normal flat 4 for the next, new 7 connector. Use red for +12vdc and black for -12vdc, and then some other color like orange for the brakes?
(I didn't even have to call on Scotty to come back in time and break the time prime directive for that. (kiss = keep it simple stupid?))

I think I'll stick with the flat 4 I have, and put in a LONGGG #10 +/- with a 10amp self resetting breaker and a "lighter type" connector at the trunk/rear hatch of the towing vehicle. (a rectifier would be nice to keep the trailer battery from trying to start the car or discharging into the primary battery, but then I'd need a 10 amp self resetting circuit breaker and a 10 amp rectifier, both radioshack parts I think. (and a really big heat sink for the rectifier) but it would be the ideal system then. Ignition-off would keep the first TV battery from discharging into the RV battery.

[rossjools]

, Just a quick question here. Do you Amercian friends have Anderson plugs over there? These are a grey 2 pin plug and 2 pin socket used for running charging wires to a trailer. They come in various sizes up to 50 amp. We also have the 7 pin round and 7 pin flat plugs and sockets here but the smallest number of pins in an Aussie plug is 5 and these are round plugs and sockets.

,
Ross.

[Dale M.]

Yes we have Anderson plugs.... Do we use them, not to much for trailer towing, for "other high amperage applications, yes... Like portable electric winches for "off road" and some tow trucks (recovery ) use them has "jumper cable" access on both ends of tow trucks...

Most US vehicles will either use the 4 pin flat connector and usually only have road lighting and no brakes or charging circuits, all other have pretty much fallen into the 7 pin "round" RV style (flat blade type) connector category which usually has all road lights, a connection for ELECTRIC brakes and a 12 volts source the can be used for "anything" like battery charging on the road...



Not everybody follows same color schemes (even electrons are color blind) but most people do wire pinouts by "function" ... For a pretty good across the spectrum compatibility...

Dale

[bdosborn]

I have a jumper that I stick into the #3 and #4 positions of our 7 way plug. It turns on the running lights of the trailer. I saw somebody do it at a teardrop gathering and its kind of a fun way to make your trailer standout at night in the campground.

Bruce

[shootr]

As you can tell from my post count I'm as noob as you can get.

As I formulate my design this summer to start a build in the fall, I'll be searching and asking a lot.

For this thread:

My 2012 Tacoma PU has a 400W min. inverter factory installed, with a 110 outlet in the bed of the truck. My super simple first idea was to have a small battery charger on the tear batteries full time, and just plug an extension cord in from the bed to the trailer to charge while driving. Any overcharging issues would be handled by the charger's electronics, it doesn't draw 400 watts, so is there anything else I'm missing (besides the disgusted looks of others at my podunk solution)?

Thanks!

[Richard A.]

My 2012 Tacoma PU has a 400W min. inverter factory installed, with a 110 outlet in the bed of the truck. My super simple first idea was to have a small battery charger on the tear batteries full time, and just plug an extension cord in from the bed to the trailer to charge while driving. Any overcharging issues would be handled by the charger's electronics, it doesn't draw 400 watts, so is there anything else I'm missing (besides the disgusted looks of others at my podunk solution)?

It might work just fine ... or not.

What I see as the biggest problem is that most inverters are not "true sine wave" inverters. They are (what the industry calls) "modified sine wave" inverters. After looking at the waveform I prefer to call them "modified square wave" inverters .. but that's just me.

Such inverters often have a problem powering certain electronic devices. Depending on how sofisticated your battery charger is (and some of them can be quite sofisticated) it may, or may not, have a problem. Frankly there is no way to tell ahead of time. I would not connect a "dumb" battery charger (also called a "manual" charger) since they have NO smarts at all and will overcharge if left on too long.

[Mloves2camp]

Just heard about this gizmo today while hanging at the river with my son & his clan. This would be to charge up the trailer battery off the car once we're parked. It's jumper 'cables' that you plug into your 12V outlets. Figured this way, the car kinda regulates the charge & there won't be as many worries about frying any computer stuff with the car. I have the charge monitor thing for back up. Any thoughts I may want to consider? Should work, right? Figured this would be just as easy as having to mess with wiring & such, which I don't know much about. Yay or nay?


Sharper Image Easy Quick Car Jumper Kit - Replaces Jumper Cables

http://www.ebay.com/itm/170746939542?ss ... 1497.l2649

[Richard A.]

Just heard about this gizmo today while hanging at the river with my son & his clan. This would be to charge up the trailer battery off the car once we're parked. It's jumper 'cables' that you plug into your 12V outlets. Figured this way, the car kinda regulates the charge & there won't be as many worries about frying any computer stuff with the car. I have the charge monitor thing for back up. Any thoughts I may want to consider? Should work, right? Figured this would be just as easy as having to mess with wiring & such, which I don't know much about. Yay or nay?

Don't think it is a good idea. If you do this while parked .. are you going to run the engine? If not you can drain your car battery down. Also the wire is fairly thin. It won't handle much current. Both ends are cigarette lighter plugs .. you would need to adapt one end and also add wire to reach the trailer. All in all more negatives to this than positives.