How to stop Zappi EV charger completely draining a PylonTech battery on a Solis inverter

brendandonlon · 23-09-2022 10:44am #1

Hello all - apologies if this has been answered in a previous discussion…

I've just installed a 6.75kw Solar PV system with a 3.5kw Pylontech battery attached to a 6kw Solis inverter. Prior to this, I already had a Zappi EV charger.

If I charge an EV on fast mode, the Solar PV battery is drained completely, and then the Solis inverter gives me a CAN_Comm_FAIL error message and the battery goes offline. I have to restart the battery, and set it to be charged off the grid for a few minutes to get it back online again.

Is there somewhere in the Solis inverter settings where I can set a limit on how much the battery can be drained?

Is there a simple way to use the Zappi charger so it doesn't use the battery at all - only grid and excess PV?

Thanks in advance…

jkforde · 23-09-2022 11:10am

not possible on Fast mode, Zappi acts as house load so battery must feed it (DC coupled).

taken from 5kw RHI 5G Solis manual:

OverDischg SOC (10%~40%, default 20%): Inverter will not discharge the battery when the OverDischg SOC is reached. Battery self-discharge is unavoidable, SOC may go lower than the limit if the battery can't get charged for a long period of time.

ForceCharge SOC (5%~OverDischg SOC, default 10%): To prevent the battery going into sleep mode, when the ForceCharge SOC is reached, inverter will charge the battery using the power from either PV or Grid up to OverDischg SOC.

jkforde · 23-09-2022 11:11am

btw, 0010 is the code for Solis adv settings.. down, down, up, down

brendandonlon · 23-09-2022 11:21am

Many thanks - I'm out of the house now but will check these settings when I'm back. Default settings should be preventing what's happening, if I'm reading this right… might need to go back to the installer in case there's a more fundamental issue.

DC999 · 23-09-2022 12:33pm

Separate to that, you don't want a small battery (3kWh house) feeding a large one (car). You incur losses on both batteries. Plus empties the battery that should run the house. Some exceptions of course but wouldn't be doing it routinely.

Eco+ runs from as low as 1.4kW and whatever spare solar excess there is. There was something recently from @Jonathan afaik to set the export limit on the Zappi to stop it using the house battery. In that case it started on Eco+ but kept going as say the battery as solar excess. So it won’t charge the car when it doesn’t see a minimum solar excess. I don’t have a house battery.

Jonathan · 23-09-2022 4:15pm

https://www.boards.ie/discussion/2058264556/how-to-stop-zappi-ev-charger-completely-draining-a-pylontech-battery-on-a-solis-inverter

Set your Solis to "charge" from grid at 0A. This will run your house entirely from grid and will not drain your battery.

https://youtu.be/qCtriOPoS_Y

brendandonlon · 23-09-2022 5:01pm

Thanks - I presume I would need to manually make this change every time I charge the car? And then change it back so the battery gets filled from solar? (If so, I need to dive into automation… 🤓)

brendandonlon · 23-09-2022 5:10pm

Just checked, and Solis defaults are in place - so it should be charging the battery from the grid if it goes below 10%... But it's obviously not doing this. I'll contact the installer and see what the problem is…

jkforde · 23-09-2022 5:22pm

don't let it drain down to zero very often, you'll wreck the battery i believe, I'd charge it up and then set no battery in the inverter for now until installer can check it

brendandonlon · 24-09-2022 5:42pm

https://www.boards.ie/discussion/comment/119656240#Comment_119656240

Belated thanks to Jonathan for this comment – what level of (gulp) automation to I have to dive into in order to be able to turn this kind of setting “on” and “off” without having to climb into my attic and poke around at the inverter itself?

EDIT - just found the answer in one of Jonathan’s replies on an earlier thread: https://www.boards.ie/discussion/2058211660/solis-inverter-settings/p2 - essentially I set a time period overnight (presumably 2am to 4am) where the Solis inverter is “charging” but at 0A… as this has the effect of giving it first dibs on grid power, so when the Zappi looks for electricity the battery will be at the back of the queue. I’ll programme this and give it a try - sounds like it’s the answer. Thanks!

the_amazing_raisin · 24-09-2022 6:41pm

If you're willing to do some rewiring, I'm pretty sure if you put the Zappi on the input AC side of the inverter then the Solis won't allow the battery to discharge to power the Zappi. But it should still allow export of excess solar

Joe Darwin · 11-11-2023 9:57am

Just read the thread having the same battery discharge problem with my new EV at the min.

So I set Solis to 'charge' @ 0A at the same time as the EV needs to charge all should be fine?

What would happen if I set Solis to charge at 50A at the same time as the EV?

Would both charge at the same time from the grid?

Would be ideal in winter when solar is limitied, I could make use of the cheap energy tarrif.

graememk · 11-11-2023 10:29am

Yes it will charge from the grid if you set it to 50a

Jonathan · 11-11-2023 10:35am

https://www.boards.ie/discussion/comment/121354304#Comment_121354304

Yes, configuring the Solis to charge the battery at 0A will result in the whole house running from grid during that period. This means you won't empty your house battery into your EV.

If you set your battery to charge at 50A, it will charge your house battery at the same time at approximately 2.5kW (50A*51.2V).

Joe Darwin · 11-11-2023 10:40am

Great I'll give that a try. Once I get the passcode from my installer 🤣

Cheers for the help

graememk · 11-11-2023 10:47am

https://www.boards.ie/discussion/comment/121354425#Comment_121354425

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How to stop Zappi EV charger completely draining a PylonTech battery on a Solis inverter

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