Solar controller replacement

[Mikey B]

Hello All, Just joined with a view to asking the following :-
Years ago I set myself up an experimental solar pv system to merely power/switch on/off under cabinet lights in my kitchen. 12V solar battery, sensor under one unit to detect movement, I purchased a panel from eBay to fit on the kitchen roof (still waiting to put it on - at the moment it is leaning against a tree) it has worked well for many years. this winter it failed and I deduced it was probably the controller. I got a cheap one from eBay which looked pretty identical. however it keeps cutting out and loosing the display. having looked into it more and checking voltages etc I have found the following.
Panel output is around 36V, the battery is good voltage at 13.0V+
The issue seems to be the old controller stated input up to 40V solar input and 12V output
The new one says 12V battery 18V panel - 24V battery 36V panel. but load voltage would match the battery voltage
So here is the question (finally!) does anyone know of a reasonably priced controller which will accept my panel 36V supply but give me 12V output load and support my 12V battery? -- or is there another answer?  (maybe buy another battery to take the system up to 24V and turn the output to 12V via a DC/DC converter)
Sorry it has been a long winded question but any help will be much appreciated.