Hello. I am using the auto start (generator) function in the Cerbo to remote start my IP43 charger (relay cerbo and IP43). I have rules for low voltage (ie 23,5V) and low SOC (<80%) witch will start the IP43 to charge the batteries. However sometimes the charger will start and goes into BULK. So far it is ok. The only downside is that sometimes (complete random) the charger will not start charging. No amps going to the system. Could this be a faulty charger? I have this system so that the MPTT’s will charge as soon as solar is available. Only use IP43 in case of the rules i have stated above. It looks like the IP43 freezes sometimes and voltage of output is completely stuck. This only happens when the charger is going from stbye (remote off) to on. Also it only happens once every couple of days. All connections are solid. It looks like the charger does not “see” what the voltage is and won’t charge accordingly.
Bulk voltage set to 27,5V (MPPT’s set to 28,2V)
Float/storrage both on 26V
No smart networking connected to mppt/shunt/temp sensor.
After plug out/in mains of charger it will start normal bulk with appropriate current.
System:
Ip43 25 amp 24 volt charger
Two mppt 100\20
Cerbo s
24 volt lead acid batteries 2*230 ah
Victron smart shunt
Gx touch 50
DVCC off
Connections made via ve direct and ve direct to usb.
Yes, that is dissapointing. I notice you set the SOC for charging is 80%. Could it be the SOC has not gone below 80% when you request charging? I known that doesn’t match the voltage level but maybe the SOC is not tracking correctly?
Hi Trevor
As the auto start conditions are not AND type but OR this should not be the case. The charger switched on due to low voltage and should therefore start charging accordingly. I have now set the charger manually on so it force float most of the time. I will do another test but as far as I can see the charger does not do what it is supposed to do.
@Paul
The rebulk off set is the issue. (And possibly temperature conpensation is complicating it)
It has to drop 2.4v under float. Looking at the screen shot of your settings.
23.87v is slightly above 26v minus 2.4v… just saying alter that one to trigger it on demand.
The re-bulk voltage offset setting is used to determine the re-bulk voltage threshold that will trigger a new charge cycle; the offset is relative to the configured ‘Storage voltage’ (re-bulk voltage = storage voltage - re-bulk voltage offset). If the battery voltage falls below re-bulk voltage threshold while the charger is in float or storage stage and remains below it for one minute, the charger will move back into bulk charge stage.
I will try lowering the rebulk setting. However why does the charger not go to the bulk setting of 27,5V as is the requested voltage? The charger goes on and does go in bulk mode. So why does the charger in this state look at the rebulk offset?
It wait until the battery dips below the rebulk offset before strating a charge cycle.
Maybe with the other charge sources and the no amp draw, the charger is not charging up all the way.
Since are starting and stopping using the GX just set it correctly with the same settings as the other chargers in the system and then switch it on and off as needed.
I thought when the charger was remote off and then restarted it would go directly into bulk mode (as also can be seen in screenshot). I would expect rebulk settings when it was already on in float and then dropped below rebulk voltage. So this looks like a flaw because when it’s remote off then it is expected to start the bulk charge fresh. At the time it was supposed to start in bulk and charge there where no other dc chargers connected.
It is doing what you are telling it to do. The settings are telling it to rebulk at 23.6v.
The storage being the same setting as float are messing with it as well
See storage point 5 here. Usually it is slightly lower than float.
Storage
Summary
The battery voltage is maintained at the configured storage voltage, which is slightly reduced compared to the float voltage to minimise gassing and extend battery life whilst the battery is unused and on continuous charge.
Set it correctly. If it does not behave after that, then it is a problem. Otherwise it is just a issue due to conflicting settings.
I will keep it monitored. I have set float absorption and Rebulk settings to values as advised. Will keep you informed. This will take a time because it has happened only a few times. Most likely as you stated due to conditions where the charge algoritme is confused with the settings.
Today again same issue. Ip43 switches on and goes in bulk. No amps delivered to system only 0,2 amps. Rebulk settings all ok. Inverter switches off because of low voltage. What is wrong with this charger?
To me it lookes like the charger is just freezing up at 23,6 Volts and just stops.
Again my ip43 freezes up on 23,6 Volts. I use generator start function cerbo to start charging on certain voltage and SOC level of battery . See screenshots. Looks like IP43 just randomly does not deliver amps. Will freeze on certain voltage.
See previous post. Will work for several days (10+) and then fails. Looks like voltage freezes when remote start is activated. Therefore the charger does nothing to charge and get voltage back up again. Previous answers where that re-bulk setting was to high but this can not be the case now. My few cents is that ip43 sometimes just freezes completely after remote start is triggered and does nothing. Trigger from cerbo to start charging works flawlessly but IP43 does not do the job.
