Optimizing AGM charging?

[GallenH]

Booster+Marcopolo. Need some basic help in understanding how to properly charge. I have a Lifeline AGM, a PD controller charger with the wizzard dongle and a victron 700 monitor.

I don't know how to gauge how long to remain in the various modes on the PD and how to force it to comply with the needs of the lifeline. I've never figured out the wizzard's ability to control the stages.

Can you walk me through the procedure?

Many thanks!!

[markopolo]

If Gallen's PD unit goes through the 3 stages + boost automatically when plugged into grid power then the single battery will get fully charged. The absorption phase will be too long but not much you can do unless you're going to watch the current flow and force the charger to float when 14.4V with current having dropped to 1 or 2 amps (no other loads).

If charging by generator then you'd only want bulk or boost modes until current into the batteries drops to 5A? (just a guess) to get the batteries substantially charged with the shortest generator runtime. You could observe a few charge cycles and watch the rate of decline of current into the batteries

Lifeline states:

A voltage settingof 14.3volts ± 0.1volts ...... should be used when the battery temperature is 77°F(25°C). The battery is considered to be fully charged when the current drops below 0.5% of the battery’s rated capacity (0.5A for a 100Ah battery).

PD units lack temperature compensation unfortunately.

[GallenH]

Which brings up a question that I hadn't thought about. My 97 PW is obvioiusly an old guy. I did replace the controller/charger portion of the old Magnatek unit with one from PD that does have multi-stage charging via what they call Wizzard. It also includes a pendant whose function/operation is a mystery to me (hence part of the reason for my post). I have no idea how to actually use it and have relied on its pre-programmed control of charger. I can monitor activity since I have the Victron 700 but don't know how or what to do if something is "off" from the recommended Lifeline specs.

Oh.....the new question that I originally hadn't thought of. What we're talking about above is when the battery is charged via shore. The wire coming from the alternator goes through a 40a circuit breaker that I assume must offer some protection while charging via the alternator. My minimal wiring diagram shows this wire going directly to the circuit breaker to the battery. Ok......here's the ? Does that mean that when my battery charges while driving there is no multi-stage charging happening?

Thanks! Glenn

[booster]

Originally Posted by GallenH

Which brings up a question that I hadn't thought about. My 97 PW is obvioiusly an old guy. I did replace the controller/charger portion of the old Magnatek unit with one from PD that does have multi-stage charging via what they call Wizzard. It also includes a pendant whose function/operation is a mystery to me (hence part of the reason for my post). I have no idea how to actually use it and have relied on its pre-programmed control of charger. I can monitor activity since I have the Victron 700 but don't know how or what to do if something is "off" from the recommended Lifeline specs.

Oh.....the new question that I originally hadn't thought of. What we're talking about above is when the battery is charged via shore. The wire coming from the alternator goes through a 40a circuit breaker that I assume must offer some protection while charging via the alternator. My minimal wiring diagram shows this wire going directly to the circuit breaker to the battery. Ok......here's the ? Does that mean that when my battery charges while driving there is no multi-stage charging happening?

Thanks! Glenn

If you are charging off the van alternator, it may have some very rudimentary turn down when current drops, but it is not much and and not suited to deep cycle batteries anyway. If you drive 8 hours on batteries just off shore power, you probably overcharge them for 7 hours of the drive.


The PD charger will do 3 or 4 stage with a 4 hour absorption, which will be too long for some charges and too short for others. It does not know what the battery state of charge is.


The only item you have that knows what is going on, is the Victron, but unless it is hooked up to control the charging sources, which it likely isn't, all it can do is tell you the batteries are full, or not. Be aware that how accurate the Victron is depends completely on how well the settings are selected to match the batteries.



By watching the Victron, you can manually force the PD charger to go back into absorption if it needs more the the 4 hours, or force it out and to float if the batteries show full before the the 4 hours. You can do the same with alternator charging if you add a disconnect between the alternator and the coach batteries.


The Victron probably can be made automatic control if you do their whole networking setup, but I am not up on that, and I don't know anyone who has done it. Magnum chargers in the MS series and up can do it automatically and accurately as they have monitor in the ARC50 remote.

[GallenH]

Originally Posted by booster

If you are charging off the van alternator, it may have some very rudimentary turn down when current drops, but it is not much and and not suited to deep cycle batteries anyway. If you drive 8 hours on batteries just off shore power, you probably overcharge them for 7 hours of the drive.

So do more current RVs have something different to control current from the alternator? Is this what a DC->DC charger would be used for?

The PD charger will do 3 or 4 stage with a 4 hour absorption, which will be too long for some charges and too short for others. It does not know what the battery state of charge is.

So it is just going by some generic time algorithm?

The only item you have that knows what is going on, is the Victron, but unless it is hooked up to control the charging sources, which it likely isn't, all it can do is tell you the batteries are full, or not. Be aware that how accurate the Victron is depends completely on how well the settings are selected to match the batteries.

Yes there are a lot of settings and I tried to go by Lifeline data and recommendations to set those.

By watching the Victron, you can manually force the PD charger to go back into absorption if it needs more the the 4 hours, or force it out and to float if the batteries show full before the the 4 hours. You can do the same with alternator charging if you add a disconnect between the alternator and the coach batteries.

So I watch the Victron to see where the battery is in terms of volts, correct?
On the PD, is it the output amps that changes from stage to stage? If so would you compare the two and, say, if the battery voltage shows it's reached the end of the bulk stage and the PD is still putting out the amps for the bulk stage, you would force the PD to switch to absorption?


The Victron probably can be made automatic control if you do their whole networking setup, but I am not up on that, and I don't know anyone who has done it. Magnum chargers in the MS series and up can do it automatically and accurately as they have monitor in the ARC50 remote.

I remember a diagram you did on a hybrid of Harry's hybrid system that used a relay controlled by the Victron. I'm guessing something like but more complicated than that setup (which I know was for a different purpose).

So much I don't know. Thanks for helping me understand this. Appreciate it.

[markopolo]

This might help: https://www.progressivedyn.com/rv/ch...emote-pendant/

The Manual Switch allows the operator to check to see if the Charge Wizard is operating properly as follows:
Press and hold the Manual Switch and shortly the Indicator Light will remain “ON” all of the time, indicating the unit went into the BOOST MODE. Continue to hold the switch and shortly the Indicator Light will start blinking rapidly (every 2-3 seconds). This indicates the unit went into the NORMAL MODE. Continue to hold the switch and the unit will go into the STORAGE MODE, and the Indicator Light will start blinking slowly (every 6-8 seconds). Once the switch button is released, the Charge Wizard will again read the RV battery voltage, and after some period of time, automatically select the proper mode of operation.

We should get back to the OP's question about Victron BMV-712 Settings. You could start a new topic about the Charge Wizard if needed.

[booster]

Originally Posted by GallenH

I remember a diagram you did on a hybrid of Harry's hybrid system that used a relay controlled by the Victron. I'm guessing something like but more complicated than that setup (which I know was for a different purpose).

So much I don't know. Thanks for helping me understand this. Appreciate it.

The relay contact in the Victron is probably the most useful for controlling the cutoff from the engine alternator. It could also control the charging from the shore charger but gets more complicated. All if it would be home done or custom bought, I think. Victron makes a centrally controlled setup that ties it all together, but all the products need to be Victron and it is more tuned to big expensive setups.

[JohnnyCLE]

For education purposes, does the Victron show the voltage level and amps coming off of the generator as you drive or just the state of the batteries? Does this vary by engine rpms? Is this controllable anywhere or just as an on / off cutoff switch?

[booster]

Originally Posted by JohnnyCLE

For education purposes, does the Victron show the voltage level and amps coming off of the generator as you drive or just the state of the batteries? Does this vary by engine rpms? Is this controllable anywhere or just as an on / off cutoff switch?

I don't have a Victron, but my understanding of it from manual reading and others comments would indicate it is like other monitors in most respects.


The monitors that are shunt based basically are looking at only the battery voltage and the actual amps going into or out of the batteries. Some have a secondary battery voltage only reading that isn't part of the coach batteries in most cases.


It is wise to understand what it tells you and what it doesn't tell you especially under the various charging conditions from different sources.


First and foremost, I think, is that it only tells you what the the battery is seeing. It tells you nothing about how much DC power is being sent to the coach by the alternator, nothing about how much DC power is coming from the shore charger, nothing about how much DC power is coming from the solar. Any loads in the coach or a closed separator to the starting battery make it so you can't infer anything useful about the charging sources because you don't know how much the coach or engine might be using. It also tells you no information on any AC power anywhere in the system as it is DC only, if the question on generator was referring to AC power generation.


All this is why I wound up putting an ammeter on the cable from the engine to the coach batteries. It is a dual display ammeter, so it also shows the amps to the coach batteries only. This allows me to see how much power is going to coach and how much of that power is going to the batteries while driving, so I can easily tell when to shut off the separator and let the solar take over finishing the coach battery charging. A big side benefit of the added ammeter is the ability to easily measure alternator outputs, minus the engine use, which I needed for setting the regulator field maximum settings to control output amps from the alternators so they can run continuously with overtemp cycling needed. I currently have the alternator outputs set at 120 or 180 amps with a selector switch choice.


The Victron can do similar, but can't tell when the solar would be able to take over the charging, only when the batteries are fully charged, which is fine, too. The Victron internal relay can be set up to to open the separator when the batteries are full for a single or parallel alternator setup, or shut off the alternator field for a standalone add on alternator setup. Having the Victron do this will give very good accuracy engine charging.