[RE-wrenches] Adding battery to grid tie

[Tyrone Houck]

In case anyone is curious about the practicality of AC coupling with the MN
AIO, I have three sites(one being my home/beta test site) running AC
coupled (without any DC PV) working flawlessly. All connected through the
AC coupling terminals. All are on early firmware versions and are solaredge
inverters...I'm sure functionality has only improved with the recent FW
updates. Just my experience. I don't want to encourage ones to do anything
counter to what Zeke and Logan are advising.
Sunny Regards,




On Thu, Aug 14, 2025, 7:46 AM Zeke Yewdall via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> While the AC coupled PV system can be added to the AC backed up loads
> panel, this defeats a lot of the functionality of a dedicated AC coupled PV
> array input on the AIOs and is not recommended by most of them.   In
> theory, yes, it works on most inverters to just add it as a negative AC
> load -- and I've even AC coupled an old Trace SW, and it works fine on
> that, despite being designed and built before AC coupling was thought of.
>
> But, if it's just on the AC loads output, the inverter does not have the
> ability to drop the AC PV array separately from the load if it needs to for
> high battery charge regulating, does not have the ability to measure the PV
> array input on monitoring, and may have other issues.
>
> Zeke
>
> > *Subject:* Re: [RE-wrenches] Adding battery to grid tie
> >
> > Correct me if I'm wrong:  I believe AIOs can accept AC coupled power
> > through the load 'output' port. That leaves the Grid and Gen inputs free
> > for their roles as labelled.
> >
> > The AC coupled inverters connect via a breaker in the critical loads
> > panel.
> >
> >
> > William Miller
> > Miller Solar.com
> > 805-438-5600
> > www.millersolar.com
> >
>
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