Need help with hqst 40 amp controller

[sunshine_eggo]

Controller says 13.8. Meter says 13.8 at terminals. Battery is 13.3 at terminals and shunt. Both meters agree.

13.8V @ MPPT battery terminals, i.e., where the battery connects?

Yet, the battery measures 13.3V @ the battery terminals?

so, there's a 0.5V drop between the MPPT terminals and the battery terminals.?

Have you confirmed voltage readings with a separate meter?

When controller is at 14.2V, what is voltage at the MPPT battery terminals and what is the voltage AT the battery terminals?

 

[Bud Martin]

0.5V Vdrps with only about 4 ~ 6A of current flows, it will be worse at higher current!

 

[sunshine_eggo]

0.5V Vdrps with only about 4 ~ 6A of current flows, it will be worse at higher current!

Yep.

 

[chipster]

Thanks for all your advice. I switched to a victron 100/50 and smart shunt. It seems much better.