Victron 712 Monitor Settings

[eric1514]

I ran another test, this time bringing the percent full down to 78% and down 92.8 Ah.

I plugged the RV into shore and oddly, the converter started in normal (absorption) mode. I forced it into Boost (bulk).

After about 4 hours, I was at
96%
13.98v
12.1a.

Then the converter switched to normal mode and these were the readings
96%
13.5v
3.43a

I forced it back to boost and it went back to
96%
13.98v
12.1a

After another 2 or so hours, I was at
100%
14.3v
3.1a

I switched it to normal mode which showed 13.6v and .32a and after an hour of that I switched it to storage (float) mode where it sits now at 13.22v and 0.0a.

If I hadn't switched the converter to bulk mode initially and then again after 4 hours, the monitor would never have read 100% because I've set the trigger voltage at 14.3 and the converter will only reach that high in bulk mode. Now whether the batteries would have reached 100% charged anyway, I don't know and I can't easily test with a hydrometer because the batteries are not easily accessible at the moment. It's something I might do later as a winter project. But in normal day to day usage I don't expect the monitor to ever read 100% while I'm on the road unless the alternator causes it to happen as the converter will not typically start in bulk mode. It may show a really small tail current but that's only half of the equation for the monitor.

[markopolo]

Sounds like your testing has given you really good insight into all of this.

The PD converter only works when the RV is plugged into grid power or if you run a generator. So if you're away from home and plugged in then you don't need to be concerned about the batteries (with a PD converter).

If planning to camp often without access to grid power then solar becomes valuable. The combo of alternator for bulk charging and solar charging to finish it is very effective if done adequately.

[booster]

Originally Posted by eric1514

I ran another test, this time bringing the percent full down to 78% and down 92.8 Ah.

I plugged the RV into shore and oddly, the converter started in normal (absorption) mode. I forced it into Boost (bulk).

After about 4 hours, I was at
96%
13.98v
12.1a.

Then the converter switched to normal mode and these were the readings
96%
13.5v
3.43a

I forced it back to boost and it went back to
96%
13.98v
12.1a

After another 2 or so hours, I was at
100%
14.3v
3.1a

I switched it to normal mode which showed 13.6v and .32a and after an hour of that I switched it to storage (float) mode where it sits now at 13.22v and 0.0a.

If I hadn't switched the converter to bulk mode initially and then again after 4 hours, the monitor would never have read 100% because I've set the trigger voltage at 14.3 and the converter will only reach that high in bulk mode. Now whether the batteries would have reached 100% charged anyway, I don't know and I can't easily test with a hydrometer because the batteries are not easily accessible at the moment. It's something I might do later as a winter project. But in normal day to day usage I don't expect the monitor to ever read 100% while I'm on the road unless the alternator causes it to happen as the converter will not typically start in bulk mode. It may show a really small tail current but that's only half of the equation for the monitor.

Most of that test look very normal for AGM charging, including the time to recharge only 22%. By 4 hours you were considerably tapered on amps at 12.1a and at that point the charger timed out of boost mode. What is a bit unusual is to be that full and low on amps and not have the charger putting out full setpoint voltage of 14.4v.


The 3.1 amps is .7%C so not bad at all, but as you have seen it takes a long time to get there.


It is very possible that on the road you would not get a reset without intervention, and that is why Victron had the settings so conservative. They made the call to prioritize getting resets over the accuracy at recharging to full point. They do that because without a reset every few cycles the entire range will of readings will be inaccurate and get worse with each cycle. As you have seen with your PD, most chargers will not get the batteries to true full on their own, but with the PD you can intervene to make it happen.



When you say that the converter will never start in bulk, I assume this is because the voltage is held up by the charging from the alternator surface charge? This is pretty common and issue as most chargers look at system voltage and only run a bulk cycle if it is under 12.6-12.8v type point. Our Magnum is the same and will often get fooled by the solar, too, and require forcing to bulk to run a full cycle. Magnum knows this is an issue, as the charger will always run a cycle regardless of voltage in CC/CV mode, but not in Multistage, and they claim they will be changing it, but they haven't done it that I know of. The Magnum can't overcharge because it ends charging based on the tail current from it's internal monitor.



With the PD, you would just need to force it to bulk when you plug in if it doesn't go by itself and check the charging amps. It will probably be at higher than setpoint amps so just let the charger run until the monitor resets to 100% and then force the PD to storage mode.


The very long time needed to top off the lead acid batteries is one of the big reasons we, and others, have solar even on big battery banks with big alternators. It makes it so even short driving runs get the batteries to the point where the solar has enough output to finish the charging without shore power or more driving.


Now that you have confirmed that all is functioning as it should and understand the resetting routine Victron uses, you will have to decide if you want to do the manual interventions like you did in your test to be the most accurate and get resets, or go to more conservative settings so the meter resets more regularly by itself with no manual charging interventions but unkown if the batteries are really full or not.

[eric1514]

Originally Posted by booster

...

When you say that the converter will never start in bulk, I assume this is because the voltage is held up by the charging from the alternator surface charge? This is pretty common and issue as most chargers look at system voltage and only run a bulk cycle if it is under 12.6-12.8v type point.
...

That's interesting. I had forgotten a very important detail until now. During the day, I was trying to run down the batteries and had turned on my inverter and plugged in 2 electric throws. That evening, I unplugged everything and turned off the inverter and there was only the typical (for me) background draw of .13a. When I went to bed and also in the morning when I plugged in the charger, the battery voltage was 12.6v. The charger saw it as full and that's probably why it didn't start in bulk mode.

Even though I was down over 20% of my total 420Ah capacity, the batteries read full if you used voltage as the measure. Just goes to show you how inaccurate those idiot light gauges are and how deceiving they can be.

Also, as you noted, the PD charger will reach the tail charge parameter of 1-1.5% well before it reaches the voltage parameter of 14.3v.

[eric1514]

Originally Posted by markopolo

Sounds like your testing has given you really good insight into all of this.

The PD converter only works when the RV is plugged into grid power or if you run a generator. So if you're away from home and plugged in then you don't need to be concerned about the batteries (with a PD converter).

If planning to camp often without access to grid power then solar becomes valuable. The combo of alternator for bulk charging and solar charging to finish it is very effective if done adequately.

This has been a big project for me and the next step is solar panels. I've installed the controller, its remote monitor, circuit breakers, etc. My panels are on back order (2x200w) and I have yet to figure out how to mount them. I think I have the wire run figured out but the RV has quite a crown on the roof and these 2 panels need to run east/west. If I take a length of pipe and lay it on the roof where the panels will be, the ends are 1.5 inches off the surface. First world problem, evidently.

[markopolo]

Here`s an idea for DIY custom mounts: https://www.classbforum.com/forums/f....html#post2557

[eric1514]

Originally Posted by markopolo

Here`s an idea for DIY custom mounts: https://www.classbforum.com/forums/f....html#post2557

I was going to try something made from uni-strut but I kinda like where you made different height legs to level the panels. I can't do anything like tilting because the RV has no ladder for getting on and off the roof.

[booster]

Originally Posted by eric1514

I was going to try something made from uni-strut but I kinda like where you made different height legs to level the panels. I can't do anything like tilting because the RV has no ladder for getting on and off the roof.

Our homemade mounts are similar to Marko's, but I only used one piece of angle and than a piece of flat stock up that mounts to the side of the solar panel which they said was OK for our panels from Grape solar.


A nice thing about using the aluminum angles is that you can bend them off of 90* fairly easily by clamping on leg in a good vice and using a couple of crescent wrenches to bend the other leg up. Makes it easy to get the one leg vertical on a curved roof.

[JohnnyCLE]

Reading through this and other treads regarding proper battery maintenance it would be nice to have more consistently defined and used charging states:

First when voltage level has recovered to the maximum recommended voltage - I think this is generally recognized as the State of Charge which the Victron Monitors highlight.

Second when current flows drop to a level which show that the maximum recharge absorption has been reached even when being hammered home at absorption level voltages. This would be something like State of Recharge which is not highlighted by the Victron Monitor but the information is there to identify it.

Third would be the percentage of original Amp Hour capacity which is available. This would be something like State of Capacity and probably could only be approximated by recalibrating with a periodic load test.

Getting a measure of "State of Capacity" seems elusive and difficult and is what many people mistake for "State of Charge". It would be wonderful if the monitor people would add the ability to display all three states as prominently as "State of Charge" is displayed.

Perhaps some day.

[booster]

Interesting observations.

Originally Posted by JohnnyCLE

Reading through this and other treads regarding proper battery maintenance it would be nice to have more consistently defined and used charging states:



I agree, but some of the manufactures seem not to. Lots of the items have various names from the manufacturers.


First when voltage level has recovered to the maximum recommended voltage - I think this is generally recognized as the State of Charge which the Victron Monitors highlight.


I would not call this completely correct. The maximum voltage the monitor sees is not the biggest part of recharge % of full, only part of it. The OP's example, as mentioned earlier, is kind of odd in that the voltage is rising so slowly as the charge nears the end. It is very, very, common to reach full absorption charge voltage while still at only 80-85% full for the battery. You need to also have the amps drop to the correct level for a full battery to actually know the battery is really full. The Victron looks at both of those items in determining when to say the battery is full.


Second when current flows drop to a level which show that the maximum recharge absorption has been reached even when being hammered home at absorption level voltages. This would be something like State of Recharge which is not highlighted by the Victron Monitor but the information is there to identify it.


I think this goes back to the previous statement just above this one. The amps do not reflect anything to do with when absorption stage is reached. You start charging in bulk charge and voltage will be below the absorption rate (unless you are very near full already). The voltage will steadily climb with amps running at the max the charger can deliver. At the point that the absorption voltage is reached, the voltage quits climbing and shortly after the amps will start to drop. The BIG thing to remember is that this point has absolutely nothing to do with being an indicator of the % state of charge of the battery. A huge charger may get to that point at 60% SOC, but a small charger on the same batteries may not get to that point unit 95% SOC because they can't supply the amps needed to raise the voltage. If you only watch the voltage on a monitor, most of the time you are barely better than a plain voltmeter or idiot lights unless you are very familiar with your system and have tested what SOC the batteries are at with your charger. That stage change will be relatively constant with similar discharges but can vary with varying discharge depths. The % battery capacity is also not stellar on recharge cycles, but is on discharge cycles after resets. Charge efficiency variations muck up the recharge accuracy. Bottom line for me if I want to know how close we are to full while charging is to look at the charge amps.


Third would be the percentage of original Amp Hour capacity which is available. This would be something like State of Capacity and probably could only be approximated by recalibrating with a periodic load test.


This is one of the issues that people that battery monitor critics bring up regularly, and it certainly is true. The battery % readings are completely based on what the actual capacity is, and can't be done any other way that I know of. I have found that a full capacity test is not what I want to do as it puts some hurt on the batteries by taking them to only 10.5v and you have to maintain an exact amp load at varying voltages during the test so not easy to do at home. When we got our new battery bank, I did ten cycles down to 50% with recharge based on volts and amps. I then did a 50% and 80% discharge set of cycles, letting the batteries rest overnight before checking voltage. Rested voltage can give you pretty consistent SOC indication for repeatability, but you don't know what the actual SOC is. Since I used the rated capacity and discharged by amp hours to the 50 and 80% those points should repeat over time, so I do that same test to determine if I have lost capacity. As it turned out the voltage matched very closely to what Lifeline said it should be rested at that SOC levels. I do that test every couple of years now, and they have not changed at all, so we are doing well on taking care of them, it appears. There is also the question of if you should program the monitor with rated capacity or usable capacity (whatever % you choose to discharge), but that is another discussion and personal choice thing.


Getting a measure of "State of Capacity" seems elusive and difficult and is what many people mistake for "State of Charge". It would be wonderful if the monitor people would add the ability to display all three states as prominently as "State of Charge" is displayed.


While this would be nice, there is really no way I know of to measure what the actual capacity is in real time, no matter what Smartgauge says they can do. If you take very good care of your batteries and check capacity every 1-2 years, based on what I have seen with our system you really won't have a problem. If you have a system with poor quality batteries, bad charging and very deep discharges all the time, you might need to replace batteries every other year, so it certainly is problem with those setups as capacity will constantly dropping.


What you didn't mention, which I think is really one of the elephants in the room is that the monitors success at keeping track of what is going on is almost completely held hostage by the charging systems. If the charging is incapable of getting the batteries full so monitor can reset to a consistent accurate SOC, you stand almost no chance of accurate readings on use or recharge. The "bandaid" that even the monitor makers and installers are using is to set the monitor up to reset way before the batteries are full as they feel it is better than not resetting at all. This is what the OP had run across and found out it is difficult and time consuming to get batteries full unless you have the charging stuff that will do it automatically.


With good consistent charging, the monitors work extremely well and accurately, but without it aren't nearly as useful except as an amp hour counter. We all had hopes that quality charging equipment would find it's way to low/mid price levels, but it hasn't happened as it appears most consumers believe the claim that all the not very accurate chargers are able to charge perfectly on every system based on timers, voltage, and algorithms.


As far as to how complicated good charging is, the premise and needs are very simple, voltage and amps thresholds at the same time. It is in the implementation and integration, plus cost, that it gets tough to do.


Perhaps some day.

[JohnnyCLE]

I think we are in violent agreement.

It is clear better definition and use of terms is needed to clear up the confusion.

What your earlier posts illustrated was that the Victron monitor with factory defaults was little better than a voltmeter.

As you indicated changing defaults better captured when a battery is "full" or closer to 100% "State of Recharge". "State of Charge" seems to mean different things to different people. I am not proposing using my terms but more precise terms would be nice.

While a definitive measure of "State of Capacity" may not be possible it would seem that some indication of "Loss of Storage Capacity" should be possible given the current puts and takes and historic "State of Charge" and "Recharge" levels. This would encourage more people to pay attention to their battery care.

Given that most RVs have multiple charging sources we only need one of the sources to provide a more fine tuned charging profile. The traditional bulk charging sources of shore power Charger/Inverter and Generator seem least likely and most costly to replace. As you pointed out, many people are using Solar for absorption & float so perhaps improved solar controllers is where the biggest hope is, or maybe a DC/DC charger from a UPS source like a Lithium Ion battery would do the trick. These don't seem like overly expensive components.

[booster]

Originally Posted by JohnnyCLE

I think we are in violent agreement.

It is clear better definition and use of terms is needed to clear up the confusion.

What your earlier posts illustrated was that the Victron monitor with factory defaults was little better than a voltmeter.

As you indicated changing defaults better captured when a battery is "full" or closer to 100% "State of Recharge". "State of Charge" seems to mean different things to different people. I am not proposing using my terms but more precise terms would be nice.


It would be more appropriate, I think, to call the turning down of the monitor to match the poor charging from the sources "user defined acceptable state of under charge from charging", but that won't happen The premise that the defaults better capture when a battery is full or close to full I don't understand as they don't do that. The just show when the battery hits the user defined state of charge that is under 100% by a small or large amount or anything in between. The Victron defaults will leave many battery banks at only 80% full when it resets to 100% which is not very close to me. If there is any curiosity of how much capacity you have when full, just shut down the charging sources and disconnect the battery as soon as the monitor says full. Let it sit and then check the voltage for AGM or specific gravity for wet cells to get a somewhat accurate indication of state of charge and thus capacity at those monitor settings. If using voltage, be sure to go by the battery manufacturers voltage to SOC chart or graph, not generic ones.


While a definitive measure of "State of Capacity" may not be possible it would seem that some indication of "Loss of Storage Capacity" should be possible given the current puts and takes and historic "State of Charge" and "Recharge" levels. This would encourage more people to pay attention to their battery care.


How about loss adjusted capacity?


Given that most RVs have multiple charging sources we only need one of the sources to provide a more fine tuned charging profile. The traditional bulk charging sources of shore power Charger/Inverter and Generator seem least likely and most costly to replace. As you pointed out, many people are using Solar for absorption & float so perhaps improved solar controllers is where the biggest hope is, or maybe a DC/DC charger from a UPS source like a Lithium Ion battery would do the trick. These don't seem like overly expensive components.

One source certainly can be enough in many cases, but the other sources need to be able to be prevented from doing anything dumb, which, depending on the source happens a lot. If you have a good solar controller, and there are at least two that I know of, they will take care of the most common fault of not getting to 100% full. There is also at least one shore charger that will do the same. If you have either of them you can do good charging regularly as long as the whatever other sources you have always undercharge so can't overcharge the batteries. They can also be made so they are disconnected when the monitor has determined batteries are full.


Alternator charging is the toughest of the bunch to do, even with a standalone alternator and remote regulator. Without a regulator you have to be able to turn them off when the batteries get full as they regulate for the vehicle at too high a voltage. If you have a remote regulator or B to B charger, they will mostly undercharge so safer is set to do that. Then the solar can finish off as long as there is enough capacity to do it in solar.


I am afraid we may actually see less of the good charging stuff for lead acid batteries, not more or better, as the manufacturers are all putting the attention on lithium now. The current pricing would indicate that if you just upgrade the solar controller you might get by for $500 or so depending on which you get. Both the common ones come with built in battery monitor so you save that cost. Good shore charging is upwards of $2500 or more. Standalone alternator and regulator probably $1500. All prices are guesses and just parts without install, so taking good care of batteries is often not economically feasible or a good idea for many users. Those are the users where the default setting work with mainstream chargers and counting on getting maybe 75-85% of rated capacity and some amount of shorter life.