Microcontroller Resets automatically.

drolleman · Joined: 03 Feb 2011 Posts: 116

check your grounds. they may not be connected to actual ground. I had one floating at 30v. I was blowing a lot of devices before I found the problem. I stuck a screw driver 10' from the building in the ground and found I had a difference of 30v to the panels ground. someone used the gas line as the ground. when I installed a new ground rod problems were gone

Ttelmah · Joined: 11 Mar 2010 Posts: 20059

As I said:

"Are you sure that the bottom pin of the UPS battery is itself grounded?. I'm not sure you will find this always to be the case.".

On quite a lot of units there is a FET between the bottom of the battery and the 'ground'. This switches when the unit changes from charge mode to running.

I find the whole idea of using the internal battery 'dubious'. You may well find that it'll cause the UPS to think it has a battery failure. Most monitor how quickly the voltage drops for the load being drawn, and will give a 'failed' status if it falls faster than expected. Honestly far easier to have a small gel cell, and a suitable charger for this, and keep the system separate from the UPS.