Yeti Pro 4000 Nominal Voltage

scottnichol67
scottnichol67 Member Posts: 5 ✭✭

So, I had an incident recently where, after sitting unused for a few days my Yeti 4000 started beeping with the CHGMONERR warning. There was also an alert telling me there was a battery fault. The only way I could get the unit to power on was to plug the AC charging cable into the back of the unit. Even with it plugged in and powered on, the inverter wouldn't power the AC outputs.

Device Info menu showed me that the voltage was at 41.1 V, even though the front panel was showing 100% charge. I read some other posts here where it seemed like others were reviving the Yeti with a direct DC charge. So, I pulled out my Nomad 400 panel and plugged it in. Almost immediately the voltage started to rise. Then when the voltage got somewhere into the 50s, I was able to power up the AC outputs.

I plugged in a nearby shop vac and started it up. It ran for a few seconds, then shut off and the Yeti showed 0% charge instead of the 100% it showed just seconds ago. So, it seems to me that after sitting idle for a few days, the voltage drops and the unit doesn't display the corresponding drop in %-charge.

I guess my question is, what is the nominal voltage for the unit? Mine is currently holding steady at 53.3 V. Also does the current firmware version 1.5.8 do a better job at either reflecting the voltage drop on the front panel through the state-of-charge %, or does it better maintain the voltage while plugged into AC input power? I would think that this would be essential for emergency preparedness where the unit can sit idle for weeks until needed and the voltage could potentially drop over time.