I have a 4s2p 24v set up. I have Mc4 cables coming from opposing pos/neg that plug into Mc4 connectors on the charge controller.
The voltage at the set from the battery bank read 26.5 on my meter.
I connect the positive together but when I go to connect the negative terminals the terminals fuse themselves together and the charge controller does not turn on.
I have verified that connections are good. I have rewired the mc4 connectors 3 times with the same result. I have also tried making the connections without the plastic housing of the mc4 to verify that the connection is solid and get a very large spark as soon as I touch metal to metal on the negative. This spark fuses connectors together, making the connectors not reusable.
I have this same set on multiple other 12v battery banks with no issues. The charge controller is 24v compatible.
Like I said, the cables from the batteries test 26.5v at the mc4 terminals. Any ideas of what can be happening?
The voltage at the set from the battery bank read 26.5 on my meter.
I connect the positive together but when I go to connect the negative terminals the terminals fuse themselves together and the charge controller does not turn on.
I have verified that connections are good. I have rewired the mc4 connectors 3 times with the same result. I have also tried making the connections without the plastic housing of the mc4 to verify that the connection is solid and get a very large spark as soon as I touch metal to metal on the negative. This spark fuses connectors together, making the connectors not reusable.
I have this same set on multiple other 12v battery banks with no issues. The charge controller is 24v compatible.
Like I said, the cables from the batteries test 26.5v at the mc4 terminals. Any ideas of what can be happening?