Dead controller??

Moved over from Lead Acid deep cycle to the Lithium battery on my boat. Ensured the Li option on the Renogy Wanderer 10a controller was selected. Noted fluctuations in the PV voltage between around 14v to 16 v in full sun. After a few days in very hot weather, the controller stopped “seeing” the solar panel. Multimeter showed 20v reaching the controller, but no PV display came up on the controller screen. Battery still full (13.4v). Is the controller fried, or can it simply be reset? What should I do?

My battery is an Ecoworthy 12v 100ah LiFePo4

If you've already downloaded the manual for it, have you run through both configuration and troubleshooting per that manual? Or, are you willing to call in to Renogy's customer support and get assistance? Don't know what you've done yet, so throwing these out ...

Without knowing the exact model of your renogy, is it the correct model for LiFePO4 batteries?

Are there any error codes (if you know how to step through the settings to get to this part, per the manual)?

Do things go back to working if you remove the new LiFePO4 battery, and throw your older battery back onto this renogy model, following the manual to hook things up for such a swap?

Do things work if you power off everything, disconnect all, and then following the manual, reconnect everything in the correct order, verifying connections/polarity as you go?

Plenty of other troubleshooting steps on Renogy's website, found with a quick google search ...

Hope this helps ...

Thanks for the speedy response.
The Controller is a Renogy Wanderer 10a PWM and has the lithium battery option.
The panel is a Renogy 100w 12v flexible unit.
I will go back to the Renogy site - as you say, there are lots of troubleshooting options on it, but none so far that talk to the absence of any PV reading on the controller's screen. As there is PV voltage at the controller itself (measured with a multimeter), I suspect that part of the controller has died.
I will try reinstalling with the old deep cycle and see what happens.
Many thanks for your thoughts.
M

No error codes showing?

How old is the panel, flexible panels can have a short life. Although it may show a voltage, check for SC current, meter set to 10A current range across the panel output wires.
If the panel checks out OK connect direct to the battery as a tempory test, the battery voltage should rise slowly.

Test the battery can deliver load power and can accept a charge.

If the battery and panel test OK, the controller is faulty.

A MPPT controller would offer better performance and could help prolong battery life.