I have 3 x 12KW Hybrid Deye inverters with 8 x 10 kwhr batteries, all set up in parallel mode. I'm having this issue where the max charging amps set in the master inverter is not usually applying to each inverter. I have max amps set in the master inverter to 240 and it will only charge the batteries up to 240A. It should be 240*3 = 720A. I am able to temporarily fix the problem by shutting off all of the batteries, then breaking the parallel connection and powering down the 2 slave inverters. Then Powering the slave inverters back up and putting them back into parallel mode and then turning the batteries back on. But the issue is only resolved for a few days and then it goes back to its usual habit of only charging up to 240A (single inverter setting). Are there any known issues where Deye inverters will behave like this? I do use solar assistant with automation to handle my daily needs. So I wonder if one of the settings which gets changed is causing the inverters to fall out of sync in regards to the max charging amps. The way I know it's not working is it will send power to the grid when the batteries are nowhere near full and already charging at around 240A with no additional load at the home to take the excess power. I do switch between load priority and batter priority depending on the day of the week and the first time I discovered and fixed this was starting in battery priority then switching to load priority. I can't say if it was the setting change in itself because I went a few days before there was enough power output to justify charging more than 240A.

Have you tried updating their software?

On 2025/05/03 at 8:46 AM, abd7 said:

Have you tried updating their software?

Yes. Newer firmware doesn't fix it. I've been troubleshooting this for months and I suspect that changing the energy pattern from battery priority to load priority is what bugs the inverters out and reduces the max charging amps to around 80A per inverter. I know it's 80A per inverter because I've since added a 4th inverter to the system and instead of a max of about 12KW of charging, it's now about a max of 15KW of charging. If I break the parallel connection and do a restart then connect them back, the issue is resolved and it can charge up to the max the batteries can handle, which is up to 40KW depending on their SOC

I normally need to switch to load priority for the weekend then back to battery priority for the weekdays but will keep it as battery priority this time to verify with certainty that it's the energy pattern change bugging it out. If this is confirmed, I'll see if the distributor can talk to Deye about trying to correct the issue with a firmware update.

I need to switch to load priority on the weekend because grid electricity is cheap and I only need the batteries to charge if there's excess power. Battery priority will still charge but it'll use the battery instead of the grid as soon as the harvest reduces below the load which is not preferable. I might be able to pull some automation tricks to get around this issue but load priority is ultimately what I need for the weekend.

Confirmed that switching energy priorities is the issue. Can go all week with battery priority and will charge as fast as the solar energy harvest can come in. Switch to load priority for the weekend and it'll only charge a max of 16KW until I do a parallel break and full reset on all inverters. This seems to be some kind of bug with the inverter system. I suspect the master inverter is sending wrong information about max charging amps when the energy priority is changed. I can also bug out the parallel system by changing settings too frequently with solar assistant or around the time when a TOU setting moves to the next time slot. I solved all of that by spacing out automation changes but regardless of the timing for energy priority specifically, it will bug out when changing them. I'm guessing this is only something Deye can solve by reporting it as a bug.

Have you logged a case with Deye so they could possibly fix it in the next Firmware update?

Having same problem did you solve it?

I finally solved this issue. It was the wires to the batteries and probably the wires from the busbar to the inverters. All were of random lengths. The longer wires listed 70mm² on the insulation while the shorter ones were 2 AWG but it turns out the 70mm² was fake. When I cut everything out, it was smaller than the 2 AWG. I ran new 35mm² cables of equal lengths for all of the batteries to the busbar and 70mm² cables of equal lengths to the inverters. All quality tin-plated copper.

I can now charge up to 30KW as expected (70A for each battery limited by the BMS, 100A is the maximum limit but BMS won't allow it and that's fine). I discovered the problem by throwing a DC ammeter onto the closest battery and saw the limitations from when that battery hit 50A. Clearly, it was telling the inverters not to deliver more power and all the other batteries got less than 30A. As that battery went up with SOC, down went the amps. I was chasing inverter problems but it was a BMS issue caused by the "professionals" who installed the system. I knew the wires were not exactly the same lengths but didn't know the big cables were so small. And glad I cut it all out and went fresh because I initially ran all the math to figure how much length to add to each wire and man I would have been pissed at the result not being resolved much.

Batteries required a full drain to get their SOCs fixed too. They were way off, obviously. But even going to full charge and balancing was still way off. Still had to do a full deep cycle to get all of the capacity back. Urgh!

Also, at the start of this thread I apparently only had 3 inverters. I now have 4.