Change the Zamp panel connection from parallel to series? Any easy way?

[Overland]

On the other hand, I found this Victron video, where at 5:10 he explains why connecting the panels in series would be beneficial. 

So there’s definitely a trade off. If you spend most of your time in full sun conditions, then maybe rewiring your panels in series would be wise.

Of course, your MPPT controller would work automatically with either, which has me wondering if you could create a simple way to switch between the two configurations to match whatever conditions you’re in. 

[mjrendon]

25 minutes ago, Overland said:

Of course, your MPPT controller would work automatically with either, which has me wondering if you could create a simple way to switch between the two configurations to match whatever conditions you’re in. 

The obvious solution is one very large panel.

[John E Davies]

I think much of the conflicting info is due to residential vs mobile applications. For your home you have a very fixed set of conditions so you can plan exactly for angle and shadows. Obviously those conclusions do not translate well to an RV rooftop.

I ran across an interesting spec: Victron MPPV units are 98% efficient. PWM units are typically 75-80%. I tried in vain to find a number for the Zamp ZS-30A. The fact that they don't mention it says to me that it is low. Has anyone seen an exact figure? If you can gain 20% efficiency by simply changing types, that seems like a very logical first step for those seeking more amps.

John Davies

Spokane WA

 

Edited November 30, 2020 by John E Davies

[SeaDawg]

On the boat, with six x 100w panels on the hardtop Bimini, Paul compromised. Each two panels are wired in series, then all three strings in parallel. The two panels in series were selected by likeliness of being shaded at the same time. 

But then, we have all those shading obstructions, mast, boom, and, underway, sails. 

The Victron equipment has been great. We haven't had to plug in since the install, and even when the alternator failed in the last trip, the batteries were always charged.

Edited December 1, 2020 by SeaDawg
Typo

[mjrendon]

The biggest loss with PWM is related to the voltage drop from the PV (~19V) to Vbat (13-14.5V) through the charge controller.  Vdrop is ~6V * ?Amps = lost power. Other losses may occur in ZAMPs controller but they are going to be small relative to this loss.

[SeaDawg]

I remember reading in a number of places that mppt vs. pwm was not a big deal in efficiency in small installations. I do suspect the marginal gain of an mppt controller is most important to those of us who live on solar, and stay put for more than a few days at a time at unserviced campsites. 

The availability of service for Zamp probably drives Oliver's selection of Zamp as their product. All the big manufacturers use Zamp. And, it's well built and reliable, from what I've read.

Edited November 30, 2020 by SeaDawg

[SeaDawg]

I am really glad this topic is once again being discussed.

After we finish the Oliver install (upgrading the panels), we've been thinking about an additional panel on the outriggers of the radar arch, where we would have far fewer shade issues. 

I  was looking at a fixed high wattage single panel, from a different manufacturer.  I'm rethinking this solution,  as adding another controller won't likely be easy. And, we have plenty of room on the Victron controller for a 300 watt panel of similar voltage. 

We'll see. More time to think. One install at a time.  

Edited November 30, 2020 by SeaDawg

[mossemi]

JD, I saw a statement today indicating that MC4 connectors should never be used inside a vehicle.  They did not elaborate on their point of view, but it made me think about your desire to eliminate the Zamp roof cap SAE connections.  I think you could replace the SAE port with a stainless fender washer and gasket and mount a bulkhead MC4 connector to it.  Just thinking out loud!

Mossey

[carnivore]

This thread really motivates me to add solar to my 2019 LE2. Mossemi has already giving me plenty of advice and recommended a good book on the basics. My trailer came with the panel wiring already in the walls. One end of the wire is bundled under the street side bunk and it is also visible passing through through the area behind the stereo and then continues upward to the roof somewhere between the hulls.

My biggest unknown is exactly where is the top end of the panel cable located on the roof between the inner and outer hulls. I don’t have an opportunity to get a close look at another Oliver with solar already installed.

Can anyone shed light on how to locate the top end of the wire and where to drill the hole for the port.

 

[AndrewK]

2 hours ago, carnivore said:

My biggest unknown is exactly where is the top end of the panel cable located on the roof between the inner and outer hulls.

Can anyone shed light on how to locate the top end of the wire and where to drill the hole for the port.

You will need to use a sound generator/toner to locate the wire.  It will be approximately 17" to 18" forward of the Maxxair fan and off set to the street side a few inches.

I can provide you with more detail and direction on the complete install.  If you would like to discuss further, please PM me with your contact information.

Andrew