S18V20ALV No longer working

Hi there,

When we connected two 7.4V LiPos in series with the S18V20ALV regulator, it suddenly stopped producing an output. There was no load connected and so we thought no current was drawn.

Thank you.


What was your setup like when your regulator was working, and what is it doing now? How are you measuring the output voltage? Can you post some pictures of the board and your setup?

- Patrick

Thank you for the response.

We connected a 2s 7.4V lipo to the regulator’s input in order to adjust the output voltage with the regulator’s potentiometer. A voltmeter was used at the Vout terminal to measure the output voltage. No load was connected to the regulator. The regulator worked as expected here. (this setup is in the 1st attached photo).

Then we connected two 2s 7.4V lipos in series to the regulator. Again with no load and using a voltmeter at the output terminals. As soon as the two lipos were connected, the regulator stopped outputting any voltage.

We then went back to one lipo and the regulator still did not work (as seen in the 2nd photo).

This occurred twice to two regulators (S18V20ALV Regulators).

Photo 2 - Regulator Working When Initially Connecting 1 Lipo:

Photo 2 - Regulator Not Working After Connecting Two Lipos in Series, Then Trying 1 Lipo Again:


It appears your regulators are damaged, and from your description I do not have any guess about what could have happened. Please email us at support@pololu.com with your order information and a reference to this thread so we can set up an RMA.

By the way, if that voltage, 11.28 V, is what you want to get out of the regulator for your application, I would recommend using our higher voltage version of that regulator, the S18V20AHV, since you are at the extreme end of the output range for the lower voltage version. This graph on the product page shows those ranges.

- Patrick