<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"></div><div dir="ltr">How much PV do you have. </div><div dir="ltr"><br></div><div dir="ltr">The Outback controllers are slow. </div><div dir="ltr">If they have a lot of PV, they don’t record the high voltage spikes and they can’t regulate them fast enough when the batteries are at high % charge. </div><div dir="ltr"><br></div><div dir="ltr">I assume you’ve adjusted the calibration voltage of the CC to the battery voltage. </div><div dir="ltr"><br></div><div dir="ltr">I’d set one controller voltage setting below the other by a few 1/10’s</div><div dir="ltr"><br></div><div dir="ltr">But you might have to get a new say victron controller. I’ve had to made this change to other systems with similar problems and it’s fixed the issues. </div><div dir="ltr"><br></div><div dir="ltr">Jay</div><div dir="ltr"><br><blockquote type="cite">On Mar 15, 2026, at 4:32 PM, Zeke Yewdall via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><div dir="ltr"><div>I've got a system that is throwing occasional battery voltage sensor errors and shutting down, then turning back on when the error clears a few seconds to a minute later. Stacked system, two VFX3524's, two FM60's, 600AH of LFP batteries (EG4 LL rackmounts) in open loop. It tends to do this when the batteries are full with lots of sun out.</div><div><br></div><div>I am not 100% sure that the batteries are happy -- it's possible that the BMS's are shutting off charging, and that's causing a spike in the bus voltage the inverters are seeing. But if that's so, I don't see anything recording it. Charge controllers both report 28.2 volts as highest voltage for the day. I adjusted the absorb voltage and time down a little bit -- we had set it up a few months ago at 28.2 for 2 hours to try to get the batteries to balance better, but I took it down to 28.0 for 1 hour now. Float was at 27.1, I reduced it to 27.0.</div><div><br></div><div>But, could this be an actual problem with the inverters? Or likely still a programming issue?</div><div><br></div><div>Z</div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr">Zeke Yewdall<div>PV Engineer</div><div>NABCEP #031508-89</div><div><a href="mailto:zeke@darkforestsolar.com" target="_blank">zeke@darkforestsolar.com</a></div><div>303-523-3592</div></div></div></div></div></div>
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