Help...Charge Controller Problem

[ConBon]

My Renogy 30amp DC to DC W MPPT charge controller battery led is flashing slow red which means the battery is undercharged. When I start my engine it changes to green and all 12v items in the van work fine. The moment I turn off the engine the red light starts flashing and my puck lights, maxxair fan and caframo fan no longer operate. I drove over 10 hours in the last 2 days so the battery should have plenty of power. Also, my Victron smartshunt app says the battery is at 100%.

 

[Camper]

First thing I would do is to check the battery voltage with a digital volt meter (not what an app says it is).

 

[abnorm]

Welcome.......you've been having electrical problems for a while.....I don't KNOW how/what you are set-up BUT troubleshooting blind from here:

Sounds like a fuse is blown to the House Battery..........(the Battery isn't connected to the system)

The DC-DC powers the devices/system while the engine is running BUT the voltage can not reach the battery since the Fuse is blown

Yuma ?

PirateCamp is in the Quartzsite LTVA South til Wed......Then on to Van Aid on Plumosa Rd if you need help.

 

[frater secessus]

If the battery really is full and the house has no power at all when the engine isn't running then @abnorm has presented the likely culprit. It could happen in a scenario like this

DC-DC --> positive busbar
Battery pos --> FUSE --> positive busbar
positive busbar -> house loads

If the battery pos fuse/breaker has opened the DC-DC would provide power to the house but could not charge the battery, and the battery could not power house loads. The good news is fuses tend to be relatively cheap and it would likely be near the pos terminal of the battery bank.

Digression: itt will be a PITA at first, but making a list of all the components (brand and model) and some photos will really help both you and us understand how your system is set up.