Best I can see in documentation DVCC is not to be used with stand alone Lithium batteries like battle born. Can someone tell me why please?
asked
Why no DVCC with stand alone Lithium batteries?
Those batteries don't communicate their charge voltage and current limit to the DVCC controller (GX device). DVCC is more than just sharing voltage and current information among the chargers or manually limiting the charging current. In order to enjoy the full program, the battery must communicate its needs (stop charging, stop discharging, limit charging current, limit charging voltage, etc.) to the GX device. Battleborn does not.
"Those batteries don't communicate their charge voltage and current limit to the DVCC controller "
Correct, neither to AGM batteries and doc says enable DVCC.
"DVCC is more than just sharing voltage and current information among the chargers or manually limiting the charging current. "
I'm still confused, if it will do this with AGM why not stand alone Lithium?
I am using DVCC with Battleborn batteries. Works fine to share voltage and current readings among charging sources and limit the overall charging sources.
Unless you are using ESS, the charging sources are not synchronized. That is, they won't necessarily be in the same state (bulk, float, etc). I'm not sure why this is. It's one of the ESS features I'd like to see without using ESS since I can't use it in my travel trailer.
The reason I spent the money on the Cerbo GX is so it will control/synchronize multiple MPPT smart chargers and control a Multiplus charger. Sharing info provided by the smart shunt with battery temp sensor to all was also part of the deal. Is this a disaster?
No disaster.
The DVCC will also manage charge currents so that the maximum set in the DVCC configuration will not be exceeded. This assumes the GX device has control of the charge controller. DVCC can not control Orion DC-DC or Styla chargers.
As bathnm describes below, it simply means that all charge sources won't alwauys be in the same mode. But if charge algorithm settings are set to the same values then modes will be "pretty close".
I have DVCC enabled on my system which has standalone Lithium (and Lead) Batteries. You need DVCC enabled to be able to share a common Voltage (SVS) and Temperature (STS).
I haven't tried the Current and Voltage limiting functions as I just let the chargers deal with that and don't think I am losing out not having those.
Take a look at the VenusOS manual on this, available here. It gives two examples, one for managed Lithium batteries, aka CAN connected, which are sharing charge and discharge information (CVL, CCL, DCL). Another, is for Lead acid. As the standalone Lithium batteries are not connected to the VenusOS and supplying any information they behave like explain 2, a lead acid battery.
In example 1, the Lithium batteries, which are controlling things are providing the charge direction and charging algorithm, the charge devices are just doing what they are told. This means they are not following any bulk, absorption, float charge algorithm.
In example 2, with just voltage, current and possibly even temperature sense information being shared, the charge devices are making their own charge decision. They will decide when to enter bulk, transition to absorption and finally float. Our to the local processing and decision making they may not always transition simultaneously. Therefore for short period of times one may be bulk while another is absorption. That is assuming the device is able to handle voltage, current and temperature sense which Victron devices will over VE.Can, VE.Bus or VE.Direct.
Section 8.3 has a good definition of internal or battery driven charge algorithm.
Hope that helps.
Ah, I did not know to fully understand the Cerbo GX I must read the VenusGX manual. Okay thanks.
