Hopefully it is less than the solar panel controller output voltage.
My solar panel has voltage but low amps.
Simply touch the solar panel leads with the multi meter probes matching their corresponding polarity red to red black to black.
For example if the solar panel is rated at 175 watts and the maximum power voltage vmp is given as 23 6 volts.
Calculate the current in amps by dividing power in watts by the voltage in volts.
It is the same thing as if you had a battery that shows voltage but when you hook it up to a light bulb the battery drops to zero volts.
Short the panel and measure your isc in noon time sun use a 10 amp dmm or use a dc current clamp type meter.
100 watts 17 5 volt vmp 5 7 amps imp.
Another reason is that the panel with 0 amps can t handle any load.
Is it also possible that while rewiring your folding panel to a series connection you mixed up the and leads for the set.
Solar panel produces volts but no amps.
The battery does not have the ability to power the light bulb but will show some voltage at no load.
Open circuit voltage can vary depending on your solar panel but the readings we are usually looking for are in the range of 15 to 23v.
Connect the ve solar controller output lead to the ve battery terminal.
And running 50 feet one way run at 4 amps on 10 awg the voltage drop would be.
Measure the battery voltage.
As the pv modules are connected in series one failing pv module will shut down the entire system.
Zero output is a common problem and in nine out of ten cases it is due to a faulty inverter or charge controller.
Some prefabricated interconnect cable sets are wired in a non standard way and matching colors of the mc4 connectors will cause the panel to be wired in backwards.
Measure the solar panel controller output voltage try to get maximum voltage by angling the panels.
Some exceptions may apply based on panel type.