question

mhschreiber avatar image
mhschreiber asked

Why does Smartsolar 150/30 show battery voltage even though there's no battery connected?

The device was running fine (on 48V LiFePo4 bike batteried) but one day I noticed the battery is not charged anymore. I disconnected the battery, checked the app the voltage (of the disconnected battery) kept jumping between 48-49v.

Disconnected the PV, reconnected - same issue.


Any advice or idea? Did I fry it?


Thanks a lot!

MPPT SmartSolar
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5 Answers
delf67 avatar image
delf67 answered ·

It is not recommended to have PV connected to an MPPT without a battery connected, but I would expect the output (battery) terminals to show a voltage if there is voltage at the input (PV) terminals.

What voltage does it show with the battery connected?

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mhschreiber avatar image
mhschreiber answered ·

Thank you for the quick reply!

I just checked, it shows the same values (48-49V) when the battery is reconnected.

However, they are not correct. When manually checking the battery, I get 54V.

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delf67 avatar image
delf67 answered ·

If you just have the battery connected and no PV, does it still read the same?

There is an internal fuse in these, but it's not user-replaceable.

Check the troubleshooting guide.

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mhschreiber avatar image
mhschreiber answered ·

I will check later on and answer your question - thank you already.


In the meantime I noticed that the device now tells me th correct voltage, but shows drops in the early morning hours that make no sense. The battery was static and not in use, the drop in voltage makes little sense.1000083127.png


1000083127.png (116.6 KiB)
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mhschreiber avatar image
mhschreiber answered ·

Update: after two restarts the device is acting as expected again, I can't replicate the error.

If the error occurs again, I'll drop a note here

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