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BigDaveZJ
04-04-2017, 11:22 AM
So my truck sits outside for extended periods of time, and seems to go through batteries pretty quick. I got a small solar panel and charger from Amazon, but not sure it's enough given the 2 batteries in my truck.

This is the panel: https://www.amazon.com/gp/product/B005MVB524/ref=oh_aui_detailpage_o09_s01?ie=UTF8&psc=1

And the charge controller: https://www.amazon.com/gp/product/B00752TRNW/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1

It seems to be doing better, but I still needed to jump the truck this past weekend when it had been sitting about a month. I have brand new batteries and cables in there, but the truck has had this issue for quite some time. 01 F250 7.3

Contemplating daisy chaining another solar panel in there to get more juice, as well as wiring up a direct connection to the batteries as opposed to the current setup going through the cigarette lighter (which is on when the ignition is off).

I searched on some of the diesel forums, but most of the threads were close to 10 years old and I figure solar technology has come a long ways in that time.

fluxcap
04-04-2017, 07:18 PM
How much of the day are you getting good son solar chargers don't do so much in the shade. Your charge controller should have a place to wire in a second solar panel if so I have one you can borrow

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Stealth Crawler ZJ
04-04-2017, 09:05 PM
I've installed a plug directly to the battery and I works way better than the cig lighter plug.
As long as I'm getting decent sun it has no problems keeping right up

http://www.batteryjunction.com/coleman-58032.html?gclid=CM6ZlOaQjNMCFZ5KDQodVDQPMA
That's the one I use.


Because Jeep.

BigDaveZJ
04-05-2017, 11:31 AM
That panel is like 3-4x the output of the one I have, I'm sure that's contributing as well.

I've been putting my panel on the dash and parking the truck facing west so it gets a lot of sun in the afternoon so it's been getting juice. I'm just thinking my panels are too small. I like that Coleman one too in that it says it can be used in any weather conditions, the one I have is not waterproof. I might see if I can rig something up to mount that to the top of my toolbox or something and then wire it into the batteries, a little more of a permanent installation. I can use the smaller one for the ZJ when we're camping since I'm planning on a fridge.

Ted_Z
04-05-2017, 11:43 AM
I have a 1.5W harbor freight solar panel on mine, sits on the roof. Gets good sun 6 hours a day. Seem to work good enough on the ZJ, but I try to drive it every 2 weeks.

Check and see what your parasitic draw is with the truck off. You shouldn't see much more than about 50mA, 100mA worst case. Most batteries have about 60-ish Ah of reserve, but you don't want to pull out more than 50% between charges for best battery life.

Some math:
50mA X 24h/day is 1.2Ah a day. So you should be good for about a month between charges.
That 4.8W (peak) charger can probably put up 300mA when charging. Figure 6 hours of good sun a day, that's 1.8Ah so you should be keeping up.

Now with 100mA draw
100mA X 24h/day = 2.4Ah. Less than 2 weeks between charges. Put the solar charger in the mix you're not keeping up, but should be good for over a month between charges.

All the above of course is using guesses at actual performance, but you get the point. Less sun, more draw and you're in trouble quick.

Ted_Z
04-05-2017, 11:45 AM
Also, try putting the panel on the roof. The windshield does knock down some of the effectiveness.

BigDaveZJ
04-05-2017, 01:10 PM
I should probably start by measuring the parasitic draw. I always thought that was some super complicated thing to do, but after some quick googling it seems pretty easy. I'm assuming I'd have to disconnect one battery completely though for that part. Maybe do a test with each battery.

fpkites
04-05-2017, 05:33 PM
Parasitic draw came to mind - maybe your alarm/remote start?

BigDaveZJ
04-05-2017, 05:45 PM
Alarm, amplifier, CB, brake controller, any number of things could be causing it. I still want the solar maintainer on it, but if I can lessen its workload that's a win.

Mtn WJ
04-06-2017, 01:04 PM
I use AC plug in style battery tenders wired direct to the batteries on my Jeep and my Mustang. Sure you have a power cord to contend with but I have not had any batteries issues since doing this. I run the power cord through the grill and bring the extension cord to the grill on the outide. The Shumacher brand I have includes a simple bracket to bolt the tender inside the engine bay.

I would be concerned that 1.5 w regardless is not enough for two batteries and suggest at least two and wired direct to battery rather than through the 12V port.