I recently replaced my boat’s charger/inverter with a Multi. When external power is removed, Multi automatically switches to Invert mode. When external power is restored, Mutli does not switch to Bulk mode, even if battery level demands Bulk mode. Instead, Multi automatically switches to whatever mode was active when external power removed (Absorption or Float). If Multi power switch is manually turned off and then back on, Multi will power on in Bulk mode. How do I get Multi to automatically power on in Bulk mode when external power restored.
We are going to need to know how you programmed it. If it was updated and what other components are in the system.
There are no other components connected, just two house battery banks. Victron Connect says firmware is V481 and is current. I don’t know what changes were made to programming at time of installation. The only change I made was to adjust the charging voltages slightly to correspond to Lifeline’s recommended voltages.
Let me know if there is a particular setting you would like me to check.
Thanks for,your help.
| LX lxonline Victron Expert
15 December |
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We are going to need to know how your programmed it. If it was updated and what other components are in the system.
What batteries do you have?
Lifeline AGM, 4 x 8D in two 24v banks
17 December |
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What batteries do you have?
The Lifeline manual shows 28.54v absorption and 26.5v float at 80 degrees F., which is what I have set it for. We are in Florida so that is ambient temperature. I also I have the temperature sensor from charger attached to batteries.
17 December |
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What batteries do you have?
So does the voltage drop to the rebulk offset? That would usually be the trigger.
Voltage is low when I restore external power. It should automatically go into bulk charging mode but does not. If I physically turn unit off with switch on the face of the charger and then back on, it goes into bulk charging.
As far as I know for 24V system the voltage has to drop 2.6V below float for bulk to start again for lead acid batteries. This is the rebulk offset and is not user configurable nor is it listed in the manual. This means he batteries have to drop below 23.9V for you which is quite low due to your low float voltage.
That doesn’t make any sense. The voltage should never drop to 23.9v.
Also, when external power is applied after the unit has been off for some time, and the unit automatically restarts in absorption mode (rather than bulk mode), the charging voltage is usually in the 26v range. Absorption should be at 28.54v with decreasing amperage. The unit does not work that way.
Finally, if the unit was in Float mode when external power is turned off, then left off until voltage is reduced to below 25 volts, and then external voltage turned back on, the unit will display Float mode (not Absorption) again with charging voltage in the 26 volt range. Again, if the unit is manually shut off, and then manually turned on, it will go into Bulk mode.
So, under your scenario, shouldn’t the unit utomatically go into Absorption mode at full charging voltage (28+ volts) and then reduce amperage when external power is reapplied? It doesn’t do that.
Update your victron connect so you can update your inverter.
Then use the solar wind priority option, add a gx or a ve bus to Bluetooth dongle.
The only other thing i can think of is maybe you have a conditional ac connect option active?
The voltage can drop to 23.9V when the batteries are down at around 50% SOC or have a large current drawn from them causing voltage drop. As soon as charging is lost and surface charge disappears, the voltage will fall to around 26.0V, full battery. It will then continue to fall as the batteries discharge. If ac is restored before the voltage drops to 23.9V then it stays in float, if it is below 23.9V then it will go into either bulk or absorption depending on the current, the SOC and batteries uptake.
It sound like the ac has never been off long enough for you to deplete the batteries so far or draw high currents for them to reach the rebulk voltage.
Normally float is higher, say 27.2V or higher so the rebulk voltage will be 24.6V and will go into bulk easier.
In your quote, you say if the battery demands bulk, how are you determining if the battery demands bulk charging, typically you need to be below 80% SOC for bulk charging, above that you will be in absorption.
If it will be helpful, I can run some different scenarios, keeping exact notes as to time on/off, voltages, charging status, etc.
Please let me know. It will take a few days to do this, since I will need to shut off external power for prolonged hours each time to let voltage run down.
That doesn’t make any sense. The voltage should never drop to 23.9v.
Also, when external power is applied after the unit has been off for some time, and the unit automatically restarts in absorption mode (rather than bulk mode), the charging voltage is usually in the 26v range. Absorption should be at 28.54v with decreasing amperage. The unit does not work that way.
Finally, if the unit was in Float mode when external power is turned off, then left off until voltage is reduced to below 25 volts, and then external voltage turned back on, the unit will display Float mode (not Absorption) again with charging voltage in the 26 volt range. Again, if the unit is manually shut off, and then manually turned on, it will go into Bulk mode.
So, under your scenario, shouldn’t the unit utomatically go into Absorption mode at full charging voltage (28+ volts) and then reduce amperage when external power is reapplied? It doesn’t do that.
I just looked at setting yesterday. Conditional AC is not active.
To answer your last paragraph, if I manually turn the unit off and then on, it will go into bulk mode for whatever time, short or long, it takes for voltage to get to absorption voltage, and then it will switch into absorption mode. It does not need to be below 80% SOC to do this. It will do this when SOC is 90% or 95%.