Updated firmware on Multiplus 5 kVA from 155 to 433 as well as installed Venus GX and now Multiplus does not go into Bulk or Absorption mode - it just charges in Float mode. I restored configuration as I had it before . Charger set to Adaptive +Battery safe
Hi how was it reading its reference voltages , ie what battery monitor
was the GX on FW 2.23
I have the 48/5000 multiplus on FW433
and a venus GX on FW 2.23
and have not problems in this area
make sure DVCC is off unless you are using it
No DVCC is off , I have no MPPT's , Multiplus is just used as a grid connected UPS. The BMV is now off course integrated with the Multiplus via the Venus GX so perhaps something there - I see I had "Enable battery monitor" and State of Charge when bulk is finished ticked at 85% , however I only discharged by 10% ( SOC 90% ) - could that be something to do with it as I guess it never detected a Bulk as now its using the BMV as a Bulk detector ( previously did so internally )
Are you sure that you loaded the correct firmware version for your Multiplus unit?
Did you verify that the first 4 digits of the firmware number exactly match the first 4 digits on the sticker located on the IC chip inside your Multiplus?
I think the issue is that it does not go into Bulk mode. Goes straight to float after a discharge ( tested is down to a 10% discharge ) . Found this thread https://community.victronenergy.com/questions/175/how-do-quattro-and-multiplus-decide-to-switch-from.html
It seems to bulk mode voltage has to be 5.2 V ( 48V system ) below float setpoint before it triggers Bilk mode . I have not been able to test this yet . This certainly was not the case previously , if would always always go into Bulk with a more than 1 % drop in SOC during a discharge. Now the question when does it detect this trigger voltage - immediately after switching to charge mode ? or after a time period
That is to 're-enter' float mode after a cycle has already been completed. If the unit is off and you either turn it 'on' or to 'charger only' it should go directly into bulk phase.
Are you also having the reported issue when you just turn 'on' the Multi?
Or is re-entry into bulk phase your concern?
Have not tried switching the unit off and then on - what I'm concerned is going from inverting to charging during a normal power outage - previously would always go to bulk . Could not get that whole sequence with the mode switch right - I switched the mode switch back to ON when the Absorption LED came on and it went to float - perhaps I was to late with that , can try that again but really that is such a cumbersome way - is there no elegant way via the portal to switch to Absorption mode / bulk mode
OK, based on your latest reply it seems that your concern is bulk phase 're-entry', rather than it not ever happening.
To prove obviously just turn the unit off for a few minutes & then back on.
Although it would be nice to have an adjustable threshold trigger to 're-enter' bulk phase, in general the default logic is a good thing. You don't want the Multiplus to keep repeating multiple full charge cycles (bulk + absorption) in a short period of time when there is minimal capacity depleted from the batteries - this is not good for your batteries.
The float phase will keep things maintained until the next cycle is triggered.
You could also increase the frequency of the auto 'repeated absorption interval' if you wish.
Yes it is possible that the trigger threshold changed with the different firmware revisions.
Your comment about the on/off sequence is to activate 'forced absorption'. This requires the rocker to be rapidly switched between 'on' - 'charger only' - 'on' - 'charger only', then finally back to 'on' when the 'absorption' light is illuminated.
Thanks Mark , yes I went through that all and never got it right - I needs some practice I'd admit. Did get it to Bulk after switching off , then on as suggested. Wish you could do it with a simple command though!
Good to know it worked after turning it off.
With the 'forced absorption' sequence, just have good read of the procedure & give it a another go. I think that the key is to 'skip' the off position, but to wait 0.5 to 2 seconds when in the 'on' or 'charger only' position. Then finally you need to wait until the 'absorption' light comes on before the final switch to 'on' position.
If you really want a new charge cycle to occur regularly, then just change the 'repeated absorption interval' from 14 days to every 1 or 2 days. This way it will be automatically triggered for you.
Also maybe revise your settings for 'max absorption time' & 'repeated absorption time'. I don't know what type of batteries you are using, but for lead acid based batteries 1h max is way too short when there is a deep discharge. The Multi will automatically shorten the time if there is not a deep discharge.
Also it does not make sense to have the 'repeated absorption time' at 4 hours, which is longer than the absolute maximum - normally it's the other way around.
yep - just wondering what determines the start time fro the repated absorbtion cycle? Does it reset after reseting the device, does it reset after a discharge / charge ( with absorbtion ) cycle? How can one determine when the next repeated cycle is about to start
I don't know for sure - the timer could commence at the start or the end of end of absorption phase.
If this is important & you want to know for sure/exactly, the easiest & quickest thing would be to try it for yourself (taking note of the time when charge phase changes occur).
It would not matter what 'triggered' the previous charge cycle (complete reset, forced absorption, battery voltage falling below the threshold or repeat absorption based on the timer).
A 'new' charge cycle could also be triggered earlier/independent of this timer, based on battery voltage (dropping below the threshold).
