Pylontech acceptable forced discharge

Question

question

markess asked Apr 19, '23

Pylontech acceptable forced discharge

I have x5 US3000C pylontech batteries, so 370Ah (17.5kWh) in total in a Victron ESS residential system.

I'm looking to discharge them constantly from 100% for 3 hrs in the evening (over the summer months), since I get paid reasonably well on my export tarrif.

They are relatively new. Is there an acceptable max discharge current for this 3hrs to keep them healthy in the long-term?

Theoretically the recommended discharge is up to 185A (37A x5), but I currently set export to a total of 40A (~2kW) for 3 hrs, to be more sympathetic (so guess that's ~8A per battery)

Does any longer term pylontech users have any thoughts as to what that could be increased too?

I have a 15% min SOC set in any case, but at the minute go nowhere near that (I would go from 100% down to ~66% in 3hrs).

Thanks.

Pylontech discharge level

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2023-04-19T21:50:08Z

snoobler answered · Apr 19, 2023 at 09:50 PM

I don't have any Pylontechs, but I have some experience in their troubleshooting and optimization.

Generally speaking, LFP are really happy with 0.2C discharge while being capable of 1C discharge. Also, most LFP can discharge 2X their charge rating. Pylontech seems to follow these conventions.

I wouldn't hesitate to send 0.2C based on the total bank capacity.

Another data point - check the max CHARGE current values the batteries are sending to the GX in VRM. Select a value HALF that for a very conservative discharge.

Your existing 40A discharge is very conservative. Twice that would be near the 0.2C level.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question