Will a battery charger backfeed to solar panels?

[Silver_Is_Money]

Will my 40 amp x 24 volt battery charger backfeed to the PV modules and potentially damage them, or do charge controllers have internal diodes which would prevent this? I.E., should I throw the disconnect on my PV modules before plugging in my battery charger?

[Living Large]

Will my 40 amp x 24 volt battery charger backfeed to the PV modules and potentially damage them, or do charge controllers have internal diodes which would prevent this? I.E., should I throw the disconnect on my PV modules before plugging in my battery charger?

The answer must be "no" or else this topic would come up all the time, and there would be people forgetting and blowing up their solar arrays.

Here is something else to consider. The battery bank itself would "backfeed" to the array, if what you suggest could happen.

I just looked at some CC schematics, and in both I see a series diode as well as the main current passing device that will only function in the desired direction.

[inetdog]

If you try to connect panels to a battery without using a CC, you could have problems with backfeeding. The panels would not be damaged, but the battery could run down during the night.
Battery maintainer panels that do not require a CC usually include a built-in blocking diode.