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We currently have a Zamp 160 watt portable solar collector connected to our battery bank via the sidewall charge port. We are planning to add another 340 watts of solar panels on our roof and install a charge controller and battery monitor. Mellow Mike, I read in your blog from last March that you were not happy with how the charge two charge controllers (from the portable array and the rooftop array) worked together. You called them Duelling Controllers, and the Zamp tricked the main controller into thinking the batteries were full when they weren’t. How did you resolve this, and what advice can you give me concerning my upcoming installation so we don’t have that problem. Would also appreciate any advice about the controller we purchase and a battery monitor. We have 3 AGM group 31 12v batteries and a 400w inverter. There is not a lot of room in our camper for a very large controller/monitor. We’d like to keep it simple. Any suggestions or advice is appreciated.
Thanks2014 Northstar Arrow U
2012 Ford F-350 4x4, CC, SRWThanks for replying to my inquiry, Mike. How difficult was it to tie into your main controller? What size wire did you use, and what sort of charge plug did you use? Were you able to use the same sidewall port that you put on the back of the camper? Sorry I’m not more knowledgeable about making these types of electrical installations. I liked the easy plug and play of the Zamp, but it needs to be able to work with the new roof panels and controller that we are having installed.
2014 Northstar Arrow U
2012 Ford F-350 4x4, CC, SRWBe aware that your controller(s) need to have sufficient amp capacity for total maximum amp output plus 10% additional headroom to allow for the lense effect…The AGM wire gauge should be of sufficient amp capacity too.
Another thing to consider when mixing-adding panels (using just one controller) is that the higher voltage panel will drop to (default to) the voltage of the lower voltage output panel, thus its best to find panels with specs as similar as possible…
If it is not possible to use just one controller, then avoid using a second (i.e. in parallel) ‘multi-stage’ type controller – Having previously had the problem you’re addressing, I found an acceptable alternative which has proved to work quite well by using a second less sophisticated single-stage type controller on the second set of panels. These are available in various amperes.
My set-up is 300w on a multi-stage MPPT controller, and separately (in parallel) 140w with the single-stage controller. In practice, one system shuts off a bit earlier than the other (near the final charging stage), but this is offset with the gain of the additional panel wattage which greatly compresses available harvest time ensuring that the batteries are restored.
BTW, Some controllers have adjustable output voltage settings which when used with a second controller can be adjusted to minimize any adverse effects..
Phil
Thank you, Phil for the information. We will be having 2 monocrystalline panels of 170 watts each on the roof of our camper. The controller we plan on installing is a Blue Sky Solar Boost 3024iL MPPT (30/40 amp) with a Blue Sky IPN-ProRemote battery monitor. The Zamp portable is 160 watts (2- 80watt panels) and comes with a ZS-15AW PWM controller. So if I understand what you’re saying, if we took out the Zamp controller and wired those panels into our main controller, that would cause the voltage of the 170w rooftop panels to drop to the voltage output of the 80w Zamp panels?! I don’t think we would want to do that. Would we be better off keeping the systems separate (as is with the two different controllers) and only use the portable Zamp when we need extra solar power or are parked in the shade? Or should we replace the Zamp controller with a single stage controller like you have? I’m unsure of how to proceed now.
Mike, did your voltage in your rooftop panels drop to the voltage of the Zamp 80w panels? Or do the 2 Zamp panels act like one 160w panel, which would be close in size to our 170w panels? I’m confused.2014 Northstar Arrow U
2012 Ford F-350 4x4, CC, SRWI’m not familiar with your controller specs, but when mixing different panels (using one controller) the difference in wattages won’t matter but the differences in voltages can…Its may not be possible to find panels with ‘like’ voltages, but ideally try to stay within about 10% of each other and you should be fine – a small voltage drop will likely be offset by the extra output (Yea!!)…Make sure that your single controller and AWG wire gauge is adequate for the total amp load + 10% headroom.
Keep in mind that with solar, you are in a race against the Sun over ‘peak harvest’ hours lasting approx. 4-5 hrs depending on season and latitude. In my case I did mix panels on the 300w MPPT system alone (consisting of two 100w and two 50w) with a slight difference in voltages, but due to the extra wattage the net affect helps to optimize peak harvest time…This is the real goal…
Phil
FWIW, I just stumbled upon this great article on solar here on this forum!!
https://www.truckcamperadventure.com/2017/05/building-a-great-solar-powered-truck-camper-rig/
I am wondering if using lithium batteries would be an advantage or disadvantage in using a solar system with fixed and portable panels.
Aside from their greater, uh, make that MUCH greater expense, Lithium batteries cannot be safely recharged if the batteries are below freezing.
Regards
John
I don't like to make plans. They cause the word "PREMEDITATED" to get used in court!
DON'T FEED THE VULTURES!
My Body is a Temple! Ancient, Crumbling, Probably Cursed . . .
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