Ve Configure & Pylontech DVCC Battery Capacity

[sahmdahn (Sean Traynor)]

I have 4 US5000 Batteries with x2 48/5000-120v Quattro’s running in Split Phase with Cerbo.

In the Victron/Pylontech Guide found [here] (Victron & Pylontech UP2500, US2000, US3000, US2000C, US3000C, US5000, US5000B, US5000C, Pelio-L, UP5000, Phantom-S, Force-L1 & L2 [Victron Energy])
it mentions in Section 5.1 that the Battery Monitor for the Quattro’s needs to be enabled. I understand that I need to set the battery capacity to the specs of the US5000, but I am not sure what capacity to use. Usable or nominal?

If I use Nominal Capacity, I get 100Ah (at 48v), so 400Ah for me, but the usable capacity is only 95Ah (at 48v) per battery. It seem Section 5.1 is telling me to set it to 100Ah per battery, but I was trying to understand why.

Any help is appreciated.

[DuivertNL (Marc)]

You have to set it at nominal, so 400Ah

[WhiteCitySolar]

I’d be interested to know what the purpose of adding the capacity is when using a battery with a BMS as the inverter/charger isn’t doing any SoC tracking.

[sahmdahn (Sean Traynor)]

I have been wondering that myself. Really confused what the point of it is. I came across a few Community Posts that mentioned to follow the programming guide to the letter, so I did, but it left me wondering a lot. Always hoping to learn more.

[nickdb (Nick)]

It may relate to it being used by ESS for dynamic cutoffs…

[lxonline (LX)]

Yeah. It is the only setting necessary for ESS assistant. (So charge efficiency, soc when bulk finished make no impact)
The ve bus soc synchronises to the battery soc.

[sahmdahn (Sean Traynor)]

Good to know. Thanks all!