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rithym1964 avatar image
rithym1964 Suspended asked

Target voltage

I'm quite new to Victron MPPT controllers having used other brands for about 9 years. Nowhere on any of the various data streams - Remote Console, Dashboard or VRM can I see Target voltage ie what voltage the controller is trying to maintain allowing for charge state and temp compensation. The controllers are connected VE CAN & VE Direct cables to a Venus GX. Has this information been ommitted for a reason I see this as paramount feedback to tell the overall situation at a glance just from knowing the target voltage...

voltage
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2 Answers
Alexandra avatar image
Alexandra answered ·

@rithym1964

It will be targeting the voltages that were set on the mppt by whoever programmed it, and is goes through several stages of charging like contant voltage and constant current.

Telling SOC from voltage is inaccurate in most caes anyway, as batteries under load are drawn down in voltage. If you really want to know the State of Charge use a BMV as it counts power in and out of the bank.

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rithym1964 avatar image rithym1964 commented ·

Sorry you misunderstand my query. On my older Tristar MPPT controllers (that were on a TCP/IP network so could be read from any PC browser using the local IP) information was shown that included Target Voltage & Actual Voltage. This information alone tells you, at any time during the charge cycle what mode the controllers are in... Bulk, Absorp or Float. Comparing these two readings is paramount to understand if you have enough PV to continue the absorption cycle undisturbed when certain loads kick in and out. Otherwise you are cycling your batteries up and down several times a day which severly shortens their life. Ideally you want to bulk & absorp at the necessary current then drop in to float where the controller just reacts to loads and supplies enough current whilst staying in float. If this doesn't happen then most probably you don't have enough PV to look after the batteries and run the loads. This is why being able to see the controller Target Voltage & Actual Voltage is critical to determine this.

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rslifkin avatar image rslifkin rithym1964 commented ·

The Victron controllers tell you the current state (Bulk, Absorb, Float) and the current battery voltage. So you should be able to figure out much the same idea with that information. You just might have to do a little math based on the battery temperature reading to determine what voltage it's really targeting with temp compensation in a given mode.

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wkirby avatar image
wkirby answered ·

The Victron MPPT controllers do not read out the target Voltage in the data stream for any given charge stage stage. Just the various stages - Bulk, Absorb and Float are read out which is enough practical information to ensure your PV power is sufficient or not. For example, if you have not reached Absorb by a certain time of day that you usually do, then reduce your loads.

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rithym1964 avatar image rithym1964 commented ·

quote "Just the various stages - Bulk, Absorb and Float are read out"

No they are not. I have just checked my Remote Console & Dashboard on VRM... none of them show what stage any of the controllers are in on the monitoring page. Yes, you can dig in to the sub menus and find this information and also fire up VictronConnect but for basic 'at a glance' monitoring, the set target voltage should be right next to the actual voltage... comparing the two at any given time gives a wealth of information.

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rslifkin avatar image rslifkin rithym1964 commented ·

The "Advanced" view has a widget that will show the charger states over the course of whatever time period you want for each MPPT. So you can look back at the previous day and see if they dropped back to bulk after hitting absorb or float, for example.

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bathnm avatar image bathnm rithym1964 commented ·

Yes the charging status is displayed. Mine are externally controlled due to having a BMS and DCCV enabled.

the data is also displayed in the Victron Connect app, when you are connected to the controller. The second screen shot is from a demo device as not near my system.

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