Solar for battery charging only |
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teampitt
Newbie Joined: 09 Oct 2018 Location: Virginia Online Status: Offline Posts: 15 |
Topic: Solar for battery charging only Posted: 14 Jul 2019 at 8:06am |
I'm thinking about getting a solar panel and controller just to maintain the charge on my 12v battery r pod battery. I won't be boondocking but plugging in to 120v where it is stored is not particularly convenient. So I'm thinking that solar might be easier. What wattage system should I consider?
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podwerkz
Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966 |
Posted: 14 Jul 2019 at 8:13am |
If you install a battery cut-off switch (or manually disconnect the battery) then a small 5-10 watt solar panel with clamps hooked up to the battery will do the job. If this panel does not have a built-in controller, (only a blocking diode) then the panel should be allowed to be in sunlight for only a few hours of sun per day. Partial shade for part or most of the day will be fine.
If you plan to leave the battery connected to the 12v trailer systems, then a 50 watt panel (with solar charge controller) is a good size to use, and this assumes several hours of strong sunlight hitting the panel per day. Fifty-watt panels are cheap and easy to find (and store) but you could go larger if you ever plan to boondock. With the trailer 12v systems connected and operating, there are 'phantom loads' on the battery that must be offset by the higher wattage panel.
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r・pod 171 gone but not forgotten!
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offgrid
Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290 |
Posted: 14 Jul 2019 at 8:25am |
+1, don't go over 10 watts if you don't also install a charge controller, and that's only if you're using flooded type batteries. Do also continue to check battery water levels monthly or so while the trailer is in storage. If you don't get direct sun at your storage facility then its probably best to forget it.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
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teampitt
Newbie Joined: 09 Oct 2018 Location: Virginia Online Status: Offline Posts: 15 |
Posted: 14 Jul 2019 at 8:53am |
Awesome input. Thanks.The location gets plenty of sunlight and I likely will install a battery cutoff switch, but 50 watts sounds like a good option.
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2654 |
Posted: 14 Jul 2019 at 9:55am |
What you're talking about is a solar powered battery tender. It won't need a lot; just enough to handle the parasitic loads plus enough to keep the battery topped off. Something like this, which is available in 5, 10, and 15 watt variants.
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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teampitt
Newbie Joined: 09 Oct 2018 Location: Virginia Online Status: Offline Posts: 15 |
Posted: 14 Jul 2019 at 9:58am |
Oh, cool. Thanks for the link.
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podwerkz
Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966 |
Posted: 14 Jul 2019 at 10:22am |
In fact, a 50 watt panel will allow you to do 'lite' boondocking, and assuming good sun exposure, will keep the battery happy when dry camping if you are very sparingly using the bare minimal r-pod systems, (and also assuming LED light fixtures) and you arrive at the campsite with a fully charged battery. I have done this myself.
In other words, running the fridge on 12v (battery power) while towing for more than an hour or so will partially deplete the r-pod battery...and towing for several hours with the fridge on 12v (battery power) will likely drain it beyond the 50 watt panel's ability to recharge the battery. This is true even though you probably have a 12v charge line to the trailer thru your 7-way trailer plug. Most vehicles only supply about 5-10 amps thru this connection and the fridge pulls more than that when set to 'battery power'.
The 50 watt panel will NOT be enough to offset the power drain when using laptops, inverters, TV, game consoles, charging power tools, etc. |
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r・pod 171 gone but not forgotten!
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offgrid
Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290 |
Posted: 14 Jul 2019 at 10:54am |
Based on your original stated purpose, battery maintenance during storage, I think podwerks' original suggestion is right on. Assuming you have a flooded battery, install a battery disconnect (or manually disconnect) and install a 5 watt solar module. No charge controller needed, cheap and simple, check your water level monthly, you should be good to go. I've been maintaining batteries that way for decades now, no problems.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
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teampitt
Newbie Joined: 09 Oct 2018 Location: Virginia Online Status: Offline Posts: 15 |
Posted: 14 Jul 2019 at 3:05pm |
Hmm .... interesting solution. I might check that out as an initial option. Thanks.
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ToolmanJohn
Senior Member Joined: 23 Apr 2014 Location: Connecticut Online Status: Offline Posts: 451 |
Posted: 14 Jul 2019 at 4:15pm |
Although a small bit costlier than small wattage panels, I recommend 150 Watts WITH a good charge controller.
My 2017 camper has a 150Watt panel and I'm not even aware of the brand panel, but it does have a STECA Solarix PRS 2020 controller. It was a factory installed option, have had it in the camper since new, and I have never removed my 2 GC2 batteries since installing them myself in spring 2017. Every Spring and November, the Ph tester confirms good acid level and charge level, a 100 AMP load test confirms good, and all I have to do every couple months (especially Summer) is check water levels. The STECA controller also had a battery equalization mode which it runs every 21 hours automatically (if there's sunlight). It keeps the cells from sulfating. (PS: Holy crap those batteries are 62 pounds each and inside the nose of the trailer and are a back breaking pain to install, so I have never removed them LOL.) Batteries that are outside, on the trailer tongue in battery boxes (R-Pod) should have water levels checked monthly, or more, if the weather if hot. My Pod batteries (2 x 12 volt marine/RV deep cycle) were in separate boxes with a Blue Sea systems battery switch. But the water levels would go down during storage. Had to peek at them every couple weeks and top off with distilled water. |
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2017 ATC 7X20 Custom Toy Hauler
2013 R-Pod 177 (SOLD) 2013 VW Touareg TDI |
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