Charging the truck battery with solar- will a 1.5W panel do?

Yeah, camper is on the truck full-time and currently I'm leaving the 7-way plug unplugged (would like to leave it in eventually). Indeed the goal is to be able to jump the truck from the camper's battery bank! Months at a time- that's my objective.

I'll check the glove compartment, and anything else simple, the next time I'm climbing around it...

Sentinelist wrote:
Separately, I'm about to setup 200W of solar on top of the camper with a 30A controller and a separate battery bank (see earlier thread today regarding my Lance for install spaces). I'm hoping to use a battery isolator to tie these two together better than the camper's 7-way plug that currently connects it to the truck with a single marine battery and just drains the snot out of my truck batteries. Solving problems by complicating them!

Is the camper on the truck full time? If so you can forget about that 5 watt nonsense and let the 200w feed all batteries. I use Trik-L-Start to jump over the truck isolation relay. Truck and trailer sit for months at times and the batteries are always tip top 100% charged. The long 7-pin connection works just fine in storage.

My truck use to sit for weeks at a time with no problems. Then my battery just started to die after a few days. It took me a long time to figure it out. Some papers in my glove compartment kept the light from turning off that is all it took to drain my battery in just a couple days. That light in the glove compartment is not that big.

When I bought my 03 Chevy I would not drive it for weeks at a time. When I would go to drive it the battery was dead

...our 2004.5 Silverado 2500HD OFTEN sits for 1 or 2 months after we reconstitute it from winter storage, with absolutely no issue whatsoever vis starting (no battery minder connected, and the batteries never disconnected). We've been doing this since September 2004-- almost 10 years. Our truck batteries are OEM factory, and are just about as strong today, as the day we bought the truck. I did use a battery minder one winter over the past 10 years of storage, however, the other 9 years, no supplemental trickle charge at all.

I would say that perhaps rust has played havoc with your electrical system over the years? I rust-proof every square centimeter our truck chassis (both undercoating and the engine compartment, and every linear centimeter of brake line)) twice a year, right from the hour we took delivery from the showroom new almost 10 years ago. I wouldn't replace this 10 year old Silverado even if I was given a brand new one free from GM (I go on record here with this statement).

I can relate to the computers drawing down your battery's. When I bought my 03 Chevy I would not drive it for weeks at a time. When I would go to drive it the battery was dead. I took it to the dealer they did all sorts of tests and everything was fine. They put a big battery in it still did not fox the problem.
After I retired and I drive the truck more often, well no more dead battery problems.

if your vehicle has a computer in it. the computer will draw down the batteries in a few weeks. if the draw is large say batteries drain in less than two weeks something is wrong..
i agree, you need larger solar panels to keep the system charged.
i use a little fence/gate solar panel on my old ranger... it has -0- electronic loads..

Thanks, all. It sounds like I have a parasitic draw- I just chased one of these down in another of my vehicles last month so I'm well versed! I'll start there. After I take these puny panels back to Harbor Freight... I'm now looking at a couple good 10W panels rated highly on Amazon that I can replace them with on my dash with a charge controller each. Of note, the batteries are actually already running in parallel. I'm assuming with a charge controller on each, it won't be an issue interfering with that.

The goal is to be able to walk out after 3 months (or something) and have the trunk crank right up.

Separately, I'm about to setup 200W of solar on top of the camper with a 30A controller and a separate battery bank (see earlier thread today regarding my Lance for install spaces). I'm hoping to use a battery isolator to tie these two together better than the camper's 7-way plug that currently connects it to the truck with a single marine battery and just drains the snot out of my truck batteries. Solving problems by complicating them!

If they are draining to where they won't crank the truck after a few days without the TC plugged in the batteries are failing or you have a pretty significant parasitic draw (short somewhere). The batteries just sitting in truck should last several months. Start chasing down that short

To answer your question directly - for large batteries use 10watts per battery if not using a controller.

I recommend 5 watts to 10 watts per battery. If you have parasitic loads then aim for the high end.

Better to get 40 to 100 watts and a small controller.

Probably way too small. 12 watts would equal about 1amp with no losses.