Boulder Briefcase 200 Watt

XtremeD

Is it possible for 4 of these units to be wired in series and connected to a Victron 150/100 smart solar charge controller? This will be used to charge my RV batteries.

XtremeD

After some investigation on my GZ Boulder Briefcase panels I found the following.

It appears Boulder Briefcase 200 Watt panels are basically two 100 Watt panels wired together per GZ. My Boulders 200s are 2020 production, label pic attached.

Vmp 18.1v / Voc 21.8v

Imp 11.05a / Isc 11.76a

Max system voltage is 30V ??? Does this mean the panels can’t be wired in series where the voltage is cumulative and the amps remain the same???

Opening the junction boxes on the back the 2 panels they are wired in parallel with #12 AWG between the two panels with positive to positive and negative to negative. There does appear to be some type of capacitor that connects both positive and negative to a 3rd center terminal in each of the junction boxes … any ideas what this is?

With the panel to panel wiring in parallel then each panel’s voltage is as stated on the label and the amps for each panel is around 5.52 amp. Seems low but it’s the math right?

With 4x 200 watt Boulder panels (8x 100 watt) in the parallel configuration the total amps being sent to the charge controller is around 44.20 amps in the best of conditions.

The GZ 4x HPP combiner is made using #12 AWG on the pigtails. #12 is typically good for 20 amps. The main lead out of the combiner seems much bigger but there is no marking on the cable. Even if it was #10 AWG it’d be too small to handle the potential 44.2 amps coming from the 4x Boulder 200 watt panels into the combiner. I don’t think the GZ combiner should be used for 4x Boulder 200 watt panels, but this is what they sold me when I inquired directly with sales.

If I want to wire the panels in series I know will need to separate the wiring between two panels and I’m comfortable doing that.

Two concerns - does the max voltage of 30v prevent these panels being wired in series? My 335w Spartan panels are rated max voltage of 1500 VDC!

Second concern is the capacitors in the JB. What are the for and does this limit the ability to wire on series?

It does seem that to use these in parallel configuration the 4x combiner cannot be used to connect 4 Boulder Briefcase 200w panels. I’ll need to arrive at a different wiring configuration.

Thanks for any input!

jg164

Hi @XtremeD,

Thanks for the detailed question. It may take me more than one reply to help you out.

Here is the first thing. The small two axial lead components spanning pairs of the 3 terminals inside every Goal Zero solar panel with a junction box, are bypass diodes. AM solar has an excellent post about them here.

Next, our current offerings of solar panels, extensions and combiners were designed to only combine panels in parallel with the MPPT charge controller that has a max input of 50V and 600W.

I am still digging into the MSV value of 30V. I will reply here when I know more.

XtremeD

Thanks … I appreciate the response. I had found the bypass diode answer in the AM SOLAR blog and a few other cases. I will look forward to an answer on the “MSV 30V”.

I hope to be able to use the GZ panels in a parallel configuration with an individual #10 or #12 AWG conductor pair from the panel to a custom built combiner box which feeds (4)200 watt panels to an Victron Energy MPPT SmartSolar controller that feeds a separate battery bank in my RV. The GZ combiners will be used to connect to the Yeti 6000x to charge up that unit.

Thanks