Charge rate Multiplus

Hi

Multiplus 489/5000/70
MPPT 150/100
Freedom Won Homelite 5/4
About 3kW solar panels

I run “Optimized without battery life” on ESS
Also “Scheduled Charge” from 16H00 to 6H00

I have set “Max Charge” to 40A
When the schedule kicks in there may still be a bit of solar available
The charge is only at about 800W
If I set the current limit to 10A then it limits down fine

Why cant I get full charge rate on schedule charge

Please help

Peter

I have the same sometimes - our supply voltage is quite low. When using a lot of power and charging at the same time, the charge power is limited in order to keep it just above the low voltage reconnect voltage.

There is probably a few other possible reasons too…

Not very clear. What max charge was set to 40A, the configuration on the inverter? Or on the DVCC menu? And is the issue that you’re getting about 15A of charge max instead of the 40A you are expecting? There is nothing in scheduled charging that will throttle this limit, you should see the same issue if you set the ESS mode to Keep Batteries Charged. So you probably don’t have to tinker with schedueld charging, rather just figure out why it cannot charge faster.

First thing to do would be to check the configuration of the inverter. Perhaps that’s configured with a lower limit.

Second question: Is there a can-bms battery in the system? Maybe that is requesting a lower limit.

Third, maybe you have an AC input current limit set.

Fourth, as @tvic said, maybe the input supply voltage is low and that is just the best it can do?

40A set on DVCC
Yes
Used to work but will check the the inverter (What setting?)
CAN - BMS To Freedom Won. Max charge at 100A
A.C. limit set to 32A
A.C. input voltage about 237VAC

I wonder if it’s not a power assist type of limit?


Almost 3 hours to do 2kWh recharge.


Here is what I see …

Perfect looking at the pic - just enough watts from the panels to keep the Eskom draw low.
image

Seems like either 1) loads + recharge was more than panels could produce or 2) bad weather yesterday. Today the panels cover the loads.
image

Perfect, sun is going down, the Scheduled Charge starts - having had not enough “spare” to recharge the batts above the Min Soc.
image

OK I found your site, and for a minute I could have sworn I saw a 12A limit applied to the multi. That would fit the about 800W perfectly (12 times 50, is really closer to 600W of course).

The 12A very closely matches what is reported for the site, so I probably didn’t see something I didn’t see.

A few seconds later it went back to 65A, which is what it is set to in VE.Configure. One possibility is that someone went and reset the inverter, but I see no evidence of that.

So… sorry… if I saw what I saw, it has fixed itself now. If not, then I don’t know. I see you have quite a few sites under your name, so I assume you are an installer?

It is possible that while messing around with settings (maybe turning DVCC off at one point), a 12A limit could have been sent to the Multi. If you turn DVCC off or on, the Multi needs a VE.Bus reset, otherwise it will have old values sticking.

I had a few VE.Bus connection errors to the battery a few weeks ago. Reseated the connectors and seems to have gone away. Not a real installer just the one with the most knowledge in our family. What is the easiest way to do a bus reset?

Everything works fine. I just expect the schedule recharge to charge at 40A not ±12A. Not going to fill the batteries if we only have 2 hours between shedding at night.

The system seems fine now. I can’t see any reason it would misbehave now. Perhaps check it again later and see if it now charges properly.

This is something I did not know.

Still limiting the charging current for some reason! :confused:

I had the same issue some time ago with my two parrallel connected MP 48/3000’s. Everything was behaving strange so I re-configured both inverters back to standalone and then again to parrallel end then loaded the last configuration file I had saved and everything was functioning as it should. I would recommend resetting the device back to factory defaults with Veconfig and set up everything from scratch. Also I would set the DVCC charge limit closer to 100A, which is the battery limit. If I’m correct the DVC charge limit includes charging from all sources eg. 25A from the MPPT and 15A from the Multi’s charger = 40A.
If you don’t want to limit the inverter to much lower than it’s capacity, I would also untick that function. With ESS the system will use the max inverter capacity (wich is 4000W in this case anyway) and draw the rest from the grid (if available).
Also make sure that your voltage sense is connected on the Multi and check the set the voltage settings to FW’s specs if it’s not (55.8V on the eTowers, not sure about the LiTe’s)
I had some “high voltage” errors on my eTowers some time ago and thought one of the cells failed. Had FW to do a diagnostic check and while they were checking everything I realized the battery voltage exceeded 57V at times, even while DVCC is set to 55.8V. I checked voltages everywhere with a multimeter and found the voltage sense wire slighlty pulled out of the connector block on the MP, causing it not to make contact (blame the cat) I fixed that and voila!! no more error messages and voltage running stable at 55.8V.
What I’m trying to say is keep it simple. Don’t use ESS function that’s not necessary, check all connections and if all else fails, reset and reconfigure the system.

Disclaimer: Seeing that I’m a mechanic and not an installer I would not take anything I just said into consideration :face_with_hand_over_mouth:

Make sure your bulk, absorbtion and float voltages are set to 55.8V. I see on that one screenshot the battery voltage sits at 55.5V at 99%SOC which seems to be a little low.

Interestingly it seems to charge to the set current limit from the MPPT but not from the grid.