question

holle avatar image

MPPT 100/30 Battery voltage reading procedure

Hi.

From where does the 100/30 get the battery voltage shown in the Status Dashboard? As I do have a difference of 0.2-0.3V between 100/30 and real measured voltage at the battery itself (battery voltage lower) I guess that there are some algorithms working within 100/30.

Is this the right understanding?

Thanks for a quick answer.
Holger.

MPPT - Solar Charge Controllerbattery system voltage
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
wkirby avatar image
wkirby answered ·

It measures battery Voltage right at the terminals of the MPPT. There are no remote Voltage sense terminals.
When the MPPT is charging (current flowing through the battery cables), you'll observe a higher Voltage at the MPPT terminals than the battery. This is due to the Voltage drop over the battery cables.
At night, the MPPT readings should be the same.

2 comments
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Thanks. Does this mean that the usage of thicker cables from MPPT to the battery will eliminate this difference in voltage?

Thicker cable will minimise the Voltage drop, ideally to a point that it is no longer noticeable.

You cannot eliminate Voltage drop, it's just physics.

anthonyburke1 avatar image
anthonyburke1 answered ·

How often does it measure battery voltage?

2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.