150 watts of solar using Lance factory wiring????

[pirlbeck]

I picked up 3 Kyocera KT50 50Watt panels today for almost nothing and would like to put them on my 2009 Lance 845. These are older panels that I think have been discontinued, but the person I got them from says they were never used and while it may be hard to tell, they sure look like that may be true. I have 2 Crown 31DC130 130AH batteries and may decide to add more solar watts later. This Lance will mostly be used as a traveling camper and will not spend many days in one spot, so I am hoping the larger truck wiring I installed takes care of most of my charging needs. That being said, I can also see us taking the camper off occasionally if it looks like we are going to spend several days camped in a base camp and travel to other tourist sites in the general area. I do have a generator for backup but would only like to use it as a last resort.

Here is the spec sheet on these panels.

Kyocera KC50 specs.

Anyway, I would like to use the Lance factory 12ga solar wiring from the roof down to the charge controller. I can use larger wire/cable from the controller to the batteries, so that is not an issue. I really would like to avoid pulling or routing new, larger wiring from the roof down to the solar charge controller. I installed a Trimetric 2030 and wired in a second battery that sits in the bed of the truck and pulling new wires/cables is not a lot of fun in a smaller truck camper like this 845. If possible, I would like to just plug into the Lance installed molded connector already on the roof, but if I have to remove the plug and install a roof junction box, it would not be a huge deal to me.

My main questions are as follows.

1, AM I wasting my time starting with just 150 watts? Open roof space is somewhat limited on this roof, but I think I would be able to find room for at least another 100 watts.

2, Can I wire the panels in parallel and use the 12ga Lance wiring from the roof to the charge controller. I am going to guess that the total length of this wire would be under 10ft, maybe around 7-8 ft. If I went this way I would probably use the Bogart SC-2030 as it will interface with the Trimetric 2030 I already have installed. What is the largest total watts I could get by with running with this set up?

3, Wire the panels in series and use a MPPT controller. If done this way, I would want to add some bypass diodes to the wiring to limit the effect any shading had on the output. From what I have seen, MPPT controller are more expensive then a PWM controller and Bogart does not offer one that would interface with the Trimetric. Anyone have a recommendation for an affordable MPPT controller with a remote panel?

Thanks!

[Lwiddis]

You are correct, 2.

[2oldman]

Lwiddis wrote:
2oldman, all day and only 10 amps? He'd get more than 10.

50 amp hours, not 50 amps. 10 amps is his highest instantaneous output.

[time2roll]

10 amps is correct.
50 amp/hours is also a good estimate.

[Lwiddis]

2oldman, all day and only 10 amps? He'd get more than 10.

[KD4UPL]

If you wire 3 in series to MPPT now you can always add a second series string of 3 more in parallel with what you have. Or all 6 in series if the controller has a high enough input voltage window. Your wiring is probably good for at least 3 parallel strings of 3 (or more).

[2oldman]

Lwiddis wrote:
"AM I wasting my time starting with just 150 watts?"
No. You should be able to make 50 amps on a reasonably sunny day..

No, more like 10.

[2oldman]

pirlbeck wrote:
but putting them on the panel output is better then (than) no bypass diodes at all when wiring in series

Yes, it would be better to shut down the shaded panel.

Series wiring eliminates the combiner box and your #12 wiring is good to many more hundreds of watts.

[pirlbeck]

OK everyone thanks for the help.

Now I need to decide.....wire panels in series and go with a MPPT controller or wire panels parallel and use a PWM controller. If I go with MPPT and wire in series, adding more panels in the future may be more of a problem due to voltage limits of controller......along with shading being more of a problem. Is this correct?

Or wire panels parallel, which may mean I have to upgrade the Lance installed wiring if I want to add more panels in the future. Advantage here would be using the Bogart controller that would interface with my Trimetric.

More thoughts or input appreciated.

Thanks!

[pirlbeck]

2oldman wrote:

pirlbeck wrote:
.. series and use a MPPT controller. If done this way, I would want to add some bypass diodes to the wiring to limit the effect any shading had on the output.

I don't know of any way to add bypass diodes to a panel, which is where they go.

I think in this case the bypass diodes would have to be installed in the wiring, most likely in the combiner box. I have read a little about it online and if I understand what I read correctly, the best way is to have panels with multiple bypass diodes built in, but putting them on the panel output is better then no bypass diodes at all when wiring in series.

If I am misunderstanding this more input or corrections to my thoughts are welcome.

Thanks!

[pirlbeck]

OldShu wrote:
Are you a member of LOA (Lance Owners of America) ?

They have a whole section devoted to solar on their website for life time members.

Yes, I am a lifetime member and I have spent a little time reading about some solar installs over there. I guess I felt like this site may get a little more traffic.

Maybe I should post these questions over there.

Thanks!

[2oldman]

pirlbeck wrote:
.. series and use a MPPT controller. If done this way, I would want to add some bypass diodes to the wiring to limit the effect any shading had on the output.

I don't know of any way to add bypass diodes to a panel, which is where they go.

[fitznj]

AM I wasting my time starting with just 150 watts?

No - I started with 165W and it served me well - I upgraded to 300W when we had
3 cloudy days during a winter camping trip (when usage was high);

150W will see you through if you have reasonably sunny days.

[Lwiddis]

"AM I wasting my time starting with just 150 watts?"

No. You should be able to make 50 amps on a reasonably sunny day...that's about the use I average. With 300 watts my batts are full by noon most days. Too bad Lance cheaped out with 12 gauge wire.

[time2roll]

https://www.solarelectricsupply.com/kyocera-50-watt-solar-panel-kc50-308

Vmp 17.4
Isc 3.31

Basically this will be 10 amps max and will work great with the Bogart controller/monitor.
Existing #12 will be fine at .261 voltage drop or about 2 percent.