On a recent trip out West, we had a stretch of 7 nights dry camping with stays of 2-3 nights at a site. I was disappointed that my batteries did not recharge very much on the drives between camping sites. So when I got back home, I did some checking and found that my charging system from the Tundra needed an upgrade.
First, the charging wire size was only 12 gauge, while 10 gauge is often recommended for trailer battery charging. Secondly, the truck's alternator was suppling power to many devices and could overcharge my HiLo batteries if I did go to a heavier wire.
I ended up with a CTEK D250S Dual 20 amp charger that takes 12 vdc. power from the alternator (I put in a 8 gauge wire with 30 amp fuse and ignition activated relay) and boosts it up to the voltage level that it needs for "smart" charging of the HiLo. It also serves as an MPPT controller for my 100 watt solar panel and will supplement the solar panel power with alternator power. In the one trial I've done so far, it charged off the truck's alternator at 10 amps. Apparently that's all my batteries needed then because my "smart" 110 vac charger also only charged them at 10 amps.
I won't really know until an extended field test, but the system is working well so far.

__________________
camperD
2307C and 2010 Tundra 5.7L Double Cab
Marietta, OH

Thanks for the info. I recommend you also check out "Jack and Janets" post on his install of a pair of solar panels which he installed with the intent of increasing his charging while on the road driving. You have done a good mod with the vehicle charging but more would be better if you like boon docking. Solar would be more. The only thing I would do different than what jack did is figure a way to detach the panel easily for placement away from shade which we get a lot of back here in the Midwest. Arizona not so much.

Rick

link: http://www.hilotrailerforum.com/f28/...allation-4354/

__________________
2201 TL

2010 Nissan Titan king cab SE
4x4

Yes, I too thought Jack's solar panel mod was excellent. My solar panel is not currently roof mounted, as we try to get sites with the trailer in the shade. But after reading his mod, I am thinking about mounting it on the roof, but in a removable tilt frame so I can use it both ways. I have other HiLo projects that are higher priority, so that one is on the back burner.

__________________
camperD
2307C and 2010 Tundra 5.7L Double Cab
Marietta, OH

Just a note about solar panels and shade. In general, we've camped where there is "partial" shade, so, there's been several hours when the trailer was in sun. And, this has always worked just fine.

But, our last stay at the North Rim of the Grand Canyon had us in nearly FULL shade. (Pretty dense Ponderosa pine forest, and, we were parked facing west so the panels were mostly not in sun until afternoon and then we tended to have clouds, which reduced the light even further.)

So, I had to break out the generator and use it a couple hours in the morning and evening. This was the first time in two years - it worked, but not well due to the 2-year old gas in it. (Wouldn't run steady unless it was on half choke.) When I got home, I found the spark arrester was almost totally clogged, and I had to clean the jets. Now it runs good again and it's been stored with no gas in it.

So, I guess the generator is still a needed "standby".

- Jack

Yeah, I was monitoring our battery status pretty closely during our boondocking this summer and sweating out making it through. Having a back-up power system to the batteries and solar panel was one of the reasons I went with the CTEK charger. In effect, my tow vehicle is my generator since I can plug into it and charge my batteries. No additional weight to haul around, no additional fuel supply, and no additional storage space needed. The CTEK is about the size and weight of a brick and the 10 amp charge test I did was with the truck idling. So no significant wear on the engine. Just in case (probably more like when) we run the batteries down while boondocking, we'll have a back-up.

__________________
camperD
2307C and 2010 Tundra 5.7L Double Cab
Marietta, OH

Backup plan "C" would be to get a small Harbor Freight type generator (400W ?) and an automotive type battery charger. Just plug the charger into the genny and you are all set - direct charge to the battery. Plus you are saving wear and tear on your tow vehicle by not having to run it. Just saying..................

Bob

__________________
2014 FR Heritage Glen 282RK
2013 F250 HD 6.7L Diesel
Formerly Owned: 1995 22D Fun Chaser & 2901L Classic

Bob, if you use an inverter generator (one that supplies 117V power like mine) you can just plug the shore power cord into it. Or, if it's like mine, you can connect it directly to the battery too using the 12V output.

- Jack