Solar question. roof top panel and ground panel

[skip1221]

Good afternoon. Sunny and 94F today so a perfect day to work on my solar upgrade. I replaced my 2 Acid batteries with a pair of Lithium 12v 100 AH ones. I also upgraded the controller from the 75/15 to the 100/50. As I wanted to add a second panel.. On the victron app The roof top panel is a steady 132 Watts. Even though it is a 200 watt panel. I am trying to add a second 200 watt panel on the ground using the Zamp plug.. I reversed the wires to match the zamp plug But when I plug the second panel in It doesn't raise the input watts. I tested the zamp plug and it said there were 18 volts going through the plug so Im thinking the rooftop panel is pushing that. When I test the ground panel volts it shows 22 coming from the panel on the ground but again when I plug it into the zamp plug Nothing changes the amount it is still showing 134 watts coming in. Am I doing something wrong? My victron settings are correct

 

[chuckster57]

The solar on the side may not be going through the controller. They are generally for a panel that has its own controller and goes pretty much straight to the batteries.

 

[RacerX-KEY]

What he said…. That Zamp side port is wired directly to batteries. Do not hook your panel to it without a charge controller. You could send too high voltage to your batteries. Hopefully your new lithium batteries have high voltage protection, and the BMS would protect you, but you definitely need to be careful as you could damage your batteries.

 

[skip1221]

yikes..lol so I need a controller for the roof panel and a controller for the zamp plug.. Glad I kept the original controller as well. So can I splice into the battery line going to the roof controller or do I have to run a new line to the battery as well separate from the other controller? and thank you for the information. .I had pulled the Zamp plug out of the camper and it looked like it was spliced to another line so I thought that was from the roof.

 

[RacerX-KEY]

I was just coming back with another concern. Hopefully you didn’t present 18 v for too long but it isn’t just the batteries that could be affected as I believe you could accidentally be providing 18v to your entire 12 v system…..that could affect other appliances in your rig.

Also….you do NOT want to splice into the battery connections on your charge controller…. That would do the same thing.. You COULD splice into the solar Inputs to the charge controller but would need to consider how you wanted to connect your panels. Splicing at the charge controller Solar inputs would make a parallel connection.

If you still have your 75/15 it would be easier to put that between your ground panel and the Zamp port and then use the Victron app to network the two charge controllers together.

You already mentioned the reverse polarity on the Zamp port. With no solar panel attached to it you should read 12 V. At that port. (12-14v with your lithium batteries ). Make sure you consider that reverse polarity when you connect to your charge controller..

 

[flybouy]

As has been established the connector for a portable solar panel is connected directly to the battery. The reasoning is that most "suitcase" portable units have a built in charge controller. Working with any electrical circuits and devices can bite you if the proper information is not understood before starting the project. Thankfully, you came to the right place for advice.

 

[skip1221]

As has been established the connector for a portable solar panel is connected directly to the battery. The reasoning is that most "suitcase" portable units have a built in charge controller. Working with any electrical circuits and devices can bite you if the proper information is not understood before starting the project. Thankfully, you came to the right place for advice.

Exactly why I came here.. I can repair your car as smooth as the day you bought it. I can do a lot of things but when it comes to solar on a RV I am like a 60 year old going back to grade 4. And I know just enough to get me in a lot of trouble as shown in this thread alone..lol so I thank you all for the heads up and the help