Want to add charger to PJ 9000 bought in jan of 2020.

SO........

That's very similar to the loads I run on my "PJ 9kw" that runs my house; it's been running with the original set of FETs for over 2 years, no issues.  Worth noting that the ONLY original parts are the chassis, AC output terminals, battery terminals/wires and mainboard (haha!)  Removed or replaced everything else...high speed GS fans, GS control board, WiFi board, power button, custom transformer.

While I've done a bit of work on the PJ upgrade code towards charge (got distracted with the arrival of GS Rev. C control board prototypes!), I don't know that I'll be able to fully recommend it.  Likely your inverter has a Rev. 10.3 PJ control board, which would make programming the CPU quite difficult.

A GS Rev. C control board / WiFi board would give you a shebang boatload of features.  Down at 3500W, while you'll probably melt the stock PJ tranny with continuous loads, the FETs should survive quite well.  Not sure if your inverter has a single long mainboard or 2 small mainboards--the GS control board only has a single mainboard output.  (Being 2020, it probably is 2 small mainboards.)  If the small mainboards have all 4 caps installed & 6 FETs/board, that's basically what's in the current GS 6kw inverters (with some ferrite beads on the ribbon cable + zener diodes on the MOS boards for protection), so 6kw could be quite feasible.

If you need AC charge, I would say that you definitely would need the still-in-design Rev. C GS control board; it has significant changes/improvements specifically for AC input (as a result of our findings with the current A.1 / B boards).  Unfortunately due to it still being in design, we're looking at at least a month's delay before having any for sale.  (I'm starting to order the bulk parts for a production run now.)

Hi Josh here. I have an 8000LF and it does have the 10.3C board in it. I need to log data from the inverter and looking for a wifi solution or wired serial connection to my PC. It doesn't have the UPS feature but I don't need that function. Can you please point me in the right direction? Thanks!

Unfortunately, there is no out-of-the-box solution for this--as there is no viable data that can be gathered from the PJ inverter in it's original form.  At best, you'll get "startup info" out of the logic-level serial port on the CPU...but no continuous status data.

While we at Genetry Solar used to offer "WiFi board upgrade kits" for PJ inverters (which can do exactly what you want), as a result of multiple incremental changes with PJ inverters, we had to stop offering them.  Basically, it seemed that each hardware requirement we had was soon eliminated from the PJ inverters via modifications on their end:

• v9 and older control boards had a removable CPU board.  Made it very easy to ship a reprogrammed CPU board with the "WiFi upgrade kit."  Enter v10.3...and the CPU is not removable.
• v9 and older PJ inverters had LCD screens, with power monitoring and mounting locations.  PJ has also removed/discontinued these--and as the cases are stainless steel, it's pretty near impossible to cut holes in the chassis to make this happen. 

Starting in 2019, we tried to find ways to improve the PJ inverters.  However, each obstacle we encountered ended up pointing the finger at a particular component used in said inverters--and by the time you replace each part that poses a problem, there is literally nothing left in the original inverter that can be used to make an inverter that's actually better:

• control board needs replaced if you want upgraded firmware. Yes, it could be replaced with a reprogrammed PJ control board...but then you won't be able to fix a number of issues.  However, if you replace the control board with a GS control board, then you'll find that the chassis AC wiring is all too short, the entire front switch panel needs replaced, connectors need made, wires spliced/cut, etc.
• ...with upgraded code OR a GS control board, you'll need a WiFi board in order to get data via WiFi and/or serial, not to mention accessing any configuration...
• ...but the chassis doesn't have a mounting spot for an LCD anymore.
• If you replace the PJ control board with a GS control board, all the MOS boards all need modified (requiring SMD soldering) to prevent random FET failure.  Even if you patch these up...
• ...then if you're hoping to push >6kw, the mainboard itself has a fatal flaw, and needs replaced...
• (let's not mention that the transformer will overheat at ~3kw continuous anyway)
• ...the replacement GS mainboard won't fit the screw holes in the chassis, and for that matter, a replacement transformer won't fit in the chassis.

It is often difficult for people to understand that "you get what you pay for."  PJ inverters are great entry-level units for people just getting started with renewable energy--but as soon as you start to need specifics, you'll need to look elsewhere.

Yes, you're on the Genetry Solar forum...and as of right now, WiFi data access and command control (on local networks AND remote access) are all current features.  (Data can be read from the inverter via local network in JSON format, and from remote access via an MQTT server.  Commands on the local network are handled via HTTP POST to the inverter itself.)

A hardwired serial connection is technically possible on the current units, though not fully implemented in hardware.  The next revision of GS inverters will have electrically isolated hardwired serial communication ports on the inverter itself; you will be able to choose between RS-232, RS-485, and CANbus when ordering.