Ideal Diode

[DavidRSw]

Some solar panels will use energy stored in the battery during times when the panels are not generating power. Supposedly most panels have diodes to prevent this drain. How do we check? Should we add an external diode? Shockley or ideal? Thanks

 

[Rider]

Solar Bypass Diode Guide: This Is What You Should Know About Solar Bypass Diodes - Power From Sunlight

Solar bypass diodes are built into PV modules (usually into the PV Junction box) for two reasons: they improve overall system performance, and they provide an added level of product safety and are therefore required by regulatory agencies.

www.powerfromsunlight.com

If the panels were approved for use in the USA, it should have a diode set. First pic in the above link shows what to look for.

 

[DavidRSw]

That makes sense for large panels, yet how do we know if there is a bypass diode in smaller panels, say a battery tender solar panel? Or some panel from Harbor Freight?

 

[svetz]

Diodes burn out too, so even if they work when you get them they might not be working later.
Perhaps add a battery shunt so you can monitor both in and out?

 

[gnubie]

If there is any sort of modern charge controller between the panels and the battery discharge through the panels won't be an issue.