I have an ongoing issue with my Multiplus 2 not charging my Lithium batteries. I have read quite a few posts here about others with similar problems.
Originally, my Honda EG6500CXS with digital AVR would charge the 8 x 200AH AGM batteries. I have since replaced with 4 x 100 AH Lithium batteries. If they run out of charge. The generator will begin charging but will be thrown off at about 20% charge. Generator continues to run the house power but will not charge batteries. Only panels and MPPT will charge.
System is about 6 years old. Batteries 3 years old.
I have changed settings via the MK3-USB Interface connected to my phone and App. Reducing the Input Current Limit and disabling the UPS Function.
System is monitored by a BMV 702. When batteries run flat, it pops back to say they are 100%.
Batteries are connected to each other by RJ45 cable but NOT to the Multiplus.
I suspect I have missed something in the settings, or the BMS in the Lithium Batteries and the BMV 702 are conflicting.
I have attached photos of system, batteries, and latest settings.
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A BMV is not really sufficient to monitor a lithium based system.
You need the GX device to monitor your batteries’ BMS data.
That being said, does the charge current drop to zero before the multi goes to pass through, or does it cut off while still charging? Does the BMV share data with the multiplus?
The BMV going to 100% too early, suggests that the BMV voltage parameters are set wrong, the charged voltage and Charged time may need to be increased.
For further help, please post your Multiplus and BMV detail settings.
If it is not generator rejection (as in the inverter is disconnecting from the generator) and you mentioned it remain powering loads; then it is either a charge related setting related or the batteries are rejecting charge.
Thanks for reply.
I recently installed an Ekrano GX, but have not tried plugging the Lithium batteries into it.
Have not noticed if the charge current droids to zero veggie Multiplus guess to pass through. I think it just cuts off while still charging and guess to pass through.
BMV shares data through the Ekrano like SOC and Batt Voltage (about 0.10 difference).
Photos of setting via the Ekrano, Fiction App, and main BMV setup settings by hand.
Just checking, for your set up no ess found it correct.
Raise your dc low shutdown to 48.
Restart to 49v.
Does the same behaviour on charge happen when the inverter is switched into charger only mode?
That is a 6.5kVA generator is it not? Why are you onky pulling 6A from it it can theoretically do 15A
You have a 3kVA inverter at 6A that is a 1389 wastt from the generator. If yohr loads are around or above that then it definitely wont be charging the battery.
You might check to see what the Multi is using for its battery state of charge. The Multi has one built in with it’s own settings and these could still be set for AGM and telling the Muti the batteries are charged before they actually are.
What you should use for battery SOC depends on your battery’s integration with Ekrano and what information it supplies. If you continue to use the BMV, make sure DVCC is on in Ekrano so it feeds info to the Multi, and make sure its parameters are set for your LFP batteries.
Also make sure the BMV does not reset SOC on power up. This last item may explain why the SOC jumps to 100% on discharge.
If you are able to use the battery’s BMS, make sure it is selected in the Ekrano so all devices see the same information.
There is a “Battery monitor” selection under System in the Ekrano Settings / System menu. This defaults to automatic which will usually select the BMV over the one in the Multi. Not sure what auto will select if it sees a BMV and a battery’s internal BMS.
I understand that your batteries are not currently connected to Ekrano but it may be possible and allow you better information than the BMV.
Ok. Got that. When I changed to the Multiplus monitor the Ekrano showed system was discharging, even though we have some sun. So I changed it back to Auto.
To connect lithium batteries to Ekrano, I presume I use the CAN port in photo and connect to CAN port at back of Ekrano. Do I need a special cable or would any cable with RJ45 jack do?
The battery monitor in the Multi can only monitor DC power in/out of the Multi so with other devices (like solar charge controllers) you must have an external monitor like the BMV.
To make sure, the Battery negative connects to the Battery terminal on the BMV and NOTHING else. Everything else goes on the System or Load side, including any chassis grounding.
You will need more than a straight through cable to connect your battery bank to Ekrano. Very often, the pinouts on each end of the cable will be different. It is not guaranteed that your battery will communicate with Ekrano. You will need to find documentation specific to your battery and to Victron “GX devices”.Victron does list some compatible batteries so that’s a first thing to try. Your battery may indicate its protocol matches another battery type that Victron does support. Beyond that, you will likely need a special “driver” to make your battery appear. Sorry I can’t be of more help here since every battery will be different.
Benefits to connecting your battery to Ekrano is that the battery can then control charging and discharging based on the battery’s actual state (SOC, temperature, etc.) The Multi and Victron solar charge controllers will follow this control from the battery but other DC loads, charging sources may not.
