I am about to pull the trigger and order a bunch of components, but first I want to make sure I’ve got the right parts to be fully integrated. I’m trying to keep it as simple as I can, but still have the GX Touch display.
Lithium NG Battery, 25.6V - 300 Ah
VE.Bus BMS NG
CerboGX MK2
GX Touch 50 Display
MultiPlus-II Inverter/Charger 24/3000/70-50
SmartSolar MPPT Charge Controller 100V/30A
Up to 360W Solar (undecided on brand yet, need to see what fits)
S5U Tank Level Sensor, 1-1/2NPT - 19" (33-240 ohms)
Nations Alternator 24V 140A Alternator with WakeSpeed 500 Controller
From what I gather all of those components will talk to the CerboGX and give me a full readout on batteries, charge (alternator and solar), fresh water tank level, AC use, etc.
Does that check out?
Lastly, with the NG batteries having a built in shunt will the CerboGX give that data to the WS500 or do I need an external shunt for that? I’m not finding much about integrating with the NG batteries.
At the moment I do not think that the VE Bus BMS reports battery current and SOC to the GX device so you will need a SmartShunt to provide that info.
The VE Bus BMS leaves each individual charger to work on its own charging protocol, it does not set system wide charging. It only uses DVCC to turn the chargers off on a battery fault. The WS500 will integrate with the GX device and should be able to pick up DVCC commands, but I am not 100% sure about this. You will need to fit a shunt on the alternator output (just a simple dumb shunt) if you want to see all info on the GX device and DVCC to work properly. I have the Lynx NG BMS and WS500 and this works well and that is what most of the available info relates to.
The VE Bus BMS will not shut down any 24V DC loads, so you will need a Battery Protect for that running from the BMS ATD output. Details in the manual.
The VE Bus BMS does not isolate the battery on extreme faults so if a charger goes rogue it will keep charging. Some installers add a Tyco contactor to provide this.
By time you have added a Smartshunt, battery protect and Contactor you might like to think about the Lynx NG BMS.
Do not forget about fusing, that battery will need a high AIC rated fuse like a Class T, NH or Adler EF3.
The Victron site says the VE.Bus NG BMS doesn’t need a separate smart shunt. “It also receives current and state of charge data directly from the batteries, so there’s no need for a separate SmartShunt.” Maybe that’s a recent update for the NG model??
I’m guessing the Lynx sets system wide charging? If so, what is the benefit of that? Just trying to understand the large cost difference of the VE.Bus and Lynx. Even with the VE.Bus, Battery Protect, and a contactor I’m not halfway to the cost of a Lynx without the DC Distributor. I’m not opposed, I just haven’t discovered the justification yet.
Good point on the Battery Protect, I forgot that on my list. Everything will also be adequately fused and there will be a main shut-off as well.
A rouge charger wouldn’t be fun, I was thinking the VE.Bus’s ability to shut down the charger with the DVCC in the event of a high cell voltage would take care of that, or is that different? What are folks using to control the tyco contactor?
Thanks, I asked from some additional clarification.
I was thinking I could use the charge disconnect port to open a contactor in the event of a overvoltage/overtemp condition that isn’t corrected thru the used of DVCC.
The VE Bus BMS does not isolate the battery on extreme faults so if a charger goes rogue it will keep charging.
I am not finding any reference from Victron that shows the Lynx will isolate the battery from over charging/over voltage, only that it will tell the charger to stop charging via DVCC. A Battery Protect is still recommended with the Lynx.
I can only find where the Lynx will isolate the battery for low voltage issues.
Section 1.2 of the manual. I have a Battery Protect on my DC loads driven from ATD so they are shut down prior to the contactor opening so I still have 2 layers of protection on that. Everything else has DVCC and contactor as 2 layers of protection.
Contactor
The built-in contactor serves two purposes:
It acts as a secondary safety system to protect the battery in case the primary controls (ATC and ATD contacts as well as DVCC) fail to disable the loads and/or chargers when required.
It can be used as a remote controlled main system on/off switch via the VictronConnect app, a GX device (only Standby and On), as well as using the Remote on/off terminals.