0
\$\begingroup\$

I have MPPSolar PCM5048 MPPT which is connected between the solar panels and the batteries. It was working well until yesterday as a sudden it reads negative amps on the battery current. it keeps changing values between (-0.5 to -4 amps at 8 am. while this read should be the same but positive).

Note: I get the negative read on the Battery Current display

MPPT IN and OUT reads:

note: these reads at 8 am while the inverter is off. "no loads on the battery bank"

  • voltage input: between 90 - 100v

  • Voltage output: between 24 - 27v

  • Amps input: between 1 - 3 amps "positive" (depending on day time and battery State of charge percentage).

  • Amps output: between 3 - 5 amps "positive" (again depends on battery SOC and load).

Things I did.

1- I switched off the power inverter to make sure there is no load on the batteries. the result was getting a read between (-6 and -10 amps).

2- I switched off the breaker between the MPPT and the batteries. The result was getting a read between (-18 and -22 amps).

3- I unplugged the batteries and turned off the breaker between the panels and the MPPT and let them for 6 hours. the result was the batteries voltage was 13.1v each. (the batteries are in a good condition)

4- I re-plugged the batteries and switched on the breaker and the problem still the same.

Questions

  • What could cause this issue?

  • Is it possible that the mppt gets a faulty read? what to do if it does get a faulty read?

  • Anyway to reset the MPPT other than unplugging it?

  • Could something else other than the MPPT cause this problem?

Diagram

\$\endgroup\$
2
  • \$\begingroup\$ Schematic or it didn’t happen. Welcome to EE.SE! ”-18 and -22” What? Joules? Watts? Ohms? \$\endgroup\$
    – winny
    Mar 3 '20 at 7:46
  • \$\begingroup\$ @winny amps. I edited the post and uploaded the diagram, but looks like there is an error on the link. it does not show the uploaded image. \$\endgroup\$
    – Jaz
    Mar 3 '20 at 8:30
0
\$\begingroup\$

I have found the solution for my case.

Note: This is for my case only.

I just disconnected the earth wire from the power inverter (that's because I found that the MPPT is grounded) and connected the inverter to the battery bank. That seems to solve the problem I had.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.