Updating an RV for solar, 4-stage charging, isolated 12V??

[Reflex439]

I have a 2000 Class B RV with an older Magnetek 6345 converter. Its old technology, needs an upgrade to better fit how I want to use the RV. Some of the issues I am trying to overcome;

1. The converter is pretty stupid with regarding battery management.
2. One needs to know the state of charge to know how long it is safe to keep plugged into shore power or risk boiling off the batteries.
3. If the battery disconnect switch is in the off position while the RV is plugged into shore power, it can damage my 12V control boards in the appliances due to the 16.5V it outputs. Needless to say, some members in my family that use the RV are forgetful 😉

I know I can get around all these by micro managing the converter and batteries. But I would rather it just happen properly without my input (outside of routine maintenance of course). I.e., I can plug into shore power and leave it. A day, weeks, or even months, and know the battery is being properly handled.

My thoughts;

1. Remove the converter (Magnetek 645), and re-wire the 12V circuits to a new bus, fused, and connect the battery bank.
2. Install a 4-stage charger to manage the battery charging. The charger would run off a 120V house circuit anytime we are connected to shore power/generator.
3. Install two solar panels, 100W each, one standard and one flexible, with a controller that would work well in concert with the 4-stage charger.
4. If possible, I would like to maintain the vehicle charge via the alternator, but willing to ditch that if it isn’t an easy setup with the solar and 4-stage charger.

My biggest question; what are the advantages/disadvantages of ditching the converter and having isolated 120V and 12V circuits? What advantage do I gain with the converter? What do I loose without it?

Second, can you use a 4-start charger, solar charger, and alternator charge easily and successfully. Is it just another wire run to the battery and the chargers work it out if set properly?

Thanks in advance. I know its a mouth full

[Reflex439]

RoyB wrote:
You are making this very hard.... All that needs to be done is remove the components in the bottom of your....

Now that I know the PD-4645 supplies acceptable power to the appliances regardless if the battery is connected or not, I agree. No real reason to go through all the fuss. And even better, it looks like its a very easy swap.

Done deal, moving on to adding solar 🙂

[CJW8]

I charge my batteries with factory installed WFCO converter (Junk), Xantrex TrueCharge 40 (excellent), Solar and alternator simultaneously, or one at a time, no matter, they all sense battery voltage and do what they do accordingly.

[Almot]

SMK,

Yes, when I read write-ups on Amazon etc on "multistage" chargers, they could mean anything. Button to switch btw flooded and AGM they will count as a "stage", or equalizing mode, or desulfating, or weekly boost mode - and then a single-stage charger suddenly becomes a 4-stage :)... Can't say about converters, it's been a while since I used one.

[time2roll]

Almot wrote:
#1: You don't want to be without converter. Upgrade it, so that it wouldn't boil batteries and would output 13-14V without battery.

#2: Converter already IS a multistage charger. They are 3-stage. Illiterate Amazon descriptions might talk about 4-stage though.

#3: Solar won't have any adverse effect on other charging sources, install it if you want to minimize generator time and charge battery fuller.

#4: You don't want to ditch the alternator. There are ways to isolate the charging of starter and coach battery, if you need to.

+1 on all this.

Although the #2 question... 4 stage probably describes the daily or weekly boost charge.

[RoyB]

You are making this very hard.... All that needs to be done is remove the components in the bottom of your older Magnetek 6345 converter Chassis and just replace the bottom converter chassis electronics with a modern PD-9245 or PD-4645 to keep your same DC Current presently being used.

I would go to a 60AMP Converter unit just in case you add more batteries to the battery bank. If yo ever want to charge your battery bank in a quick three hour time frame you will need 14.4VDC with the capacity of 17-20AMPS DC for each of the batteries in your battery bank.

You keep all of the top boards in place of your current Magnetek 6345 that has the 120VAC Circuit Breakers and 12VDC Fuses. There is no need for wiring changes for any of your RV wiring. You simply remove the large DC cables from the converter chassis in the bottom compartment and replace that with a new converter chassis which only needs to be wired for its 120VAC and the three 12VDC WIRE CABLE going to the top units...

check out this series of photos this guy did with his Magnetek 6300 unit to give you an idea what is required. He is actually adding too much info making it look more complicated then it actually is but he wanted to cover every little detail...

The photos in his report is great to under stand what you will need to do...

MAGNETEK CoNVERSION


When I changed out my 35AMP Converter/Charger sytems all I had was 35AMP boox with four to five fused cables coming out of the back and all the 120VAC and 12VDC where divided up behind the the converter/charger unit and connected using the large YELLOW TWIST typee connections. I had to rewire all of my wiring in the case as I did not have the group of 120VAC Circuit breakers and 12VDC fuses panel... Wasn't really too bad or take very long as all the wires were already there. Just had to hook them up inside the new WF-8900 Power Distribution panel I used. Then in the bottom compartment I added my PD-9260C Converter/charger unit and hooked up the 120VAC cables to above Circuit Breaker and 12VDC cables to the top unit 12VDC DC BAT position lugs where required.

I would get the 12VDC Converter/charger unit problem solved first then start thinking about adding your solar panel and others changes you have in mind to do.

This is not really complicated...

Roy Ken

[Reflex439]

Almot wrote:
#1: You don't want to be without converter. Upgrade it, so that it wouldn't boil batteries and would output 13-14V without battery.

#2: Converter already IS a multistage charger. They are 3-stage. Illiterate Amazon descriptions might talk about 4-stage though.

#3: Solar won't have any adverse effect on other charging sources, install it if you want to minimize generator time and charge battery fuller.

#4: You don't want to ditch the alternator. There are ways to isolate the charging of starter and coach battery, if you need to.

Thanks. #1 is key, #2 is part of #1 :), #3 is great to hear, and #4 is probably already solved as the there is already an alternator charging input to the battery with an isolator. So probably just a connect and go scenario.

[Reflex439]

2oldman wrote:
Is there an inverter in this mix somewhere? Do you dry camp?

If you're on shore with a charger you really don't need to have solar working with it.

I do dry camp, but no inverter. I don’t really see the need for one. The only things that won’t work off 12V or LP gas is my microwave and air conditioner. Neither of which I would use an inverter for, I’d rather fire up the generator for those and save the battery capacity. I do have a 175W inverter for small things, but even my iPad, iPhone, laptop, etc all have 12V cords to charge direct off 12V circuits.

When on shore power, no, I don’t need the solar charger in the mix. However, for simplicity sake, I’d rather have a system that will manage that for me. I would prefer no to have to turn off one system before turning on the other, and would rather have them figure out what they need to coexist and do the right thing. With that said, if I have to I will.

DrewE wrote:
I think you may be a little confused about how things are wired currently. The 120V and 12V systems are isolated from each other, except in that the converter is a 120V load and ….

Very good info. I do realize 12V and 120V are isolated circuits. I probably should have stated independent of a converter, rather that isolated.

Its starting to sound like a PD4645 upgrade to my Magnetek 6345 is the easiest way to go, and then just install a solar system and try to match the charger and controller with regard to charge voltage settings. And if the PD4645 is happy working without a battery connected, thats perfect as it solves that problem as well.

I just did some reading on filtered vs unfiltered. More knowledge is a good thing 🙂

Thanks for the info. I’ll continue researching solar systems and controllers. Installation seems like a breeze, and I already know where I can route the wiring and monitor placement. My last issue will be making enough space to update to dual batteries in the current space, or find a new location for them.

[Almot]

#1: You don't want to be without converter. Upgrade it, so that it wouldn't boil batteries and would output 13-14V without battery.

#2: Converter already IS a multistage charger. They are 3-stage. Illiterate Amazon descriptions might talk about 4-stage though.

#3: Solar won't have any adverse effect on other charging sources, install it if you want to minimize generator time and charge battery fuller.

#4: You don't want to ditch the alternator. There are ways to isolate the charging of starter and coach battery, if you need to.

[DrewE]

I think you may be a little confused about how things are wired currently. The 120V and 12V systems are isolated from each other, except in that the converter is a 120V load and simultaneously a 12V supply/charger. The fact that the 120V breakers and 12V fuses are mounted side by side is immaterial to their isolation.

A modern converter, such as a PD 9200/4600 unit, is a hardwired multistage charger. The possible advantages over something sold as a battery charger (which may not apply in every case) are that it is known to play well when left connected to the battery but not to AC power (it won't run down the battery unnecessarily), and to behave when other power sources are also present, and being hardwired to stay connected. Some battery chargers may have more sophisticated charging algorithms/techniques or more modes or controls to play with.

I'd suggest upgrading the converter portion of your electrical center to one of them, and leaving the remaining 12V distribution more or less unchanged. It may be worthwhile to run heavier power and/or ground wires to the battery, depending on what's there already. You would also need to bridge the two sections of the 12V fuse panel (the "filtered" and "unfiltered" sections) so that the converter, the battery (through the disconnect switch), and the newly joined 12V bus are all in parallel. Adding solar shouldn't cause any great headaches here.

There's generally no problems with having a modern converter, the charge line from the alternator via an isolator of some sort, and a solar charger all connected to the battery. There's also no problem with having most modern converters connected to the 12V system but not the battery; they have much better filtered output than your old converter. Some combinations of solar chargers and converters might fool each other into changing charge modes at times when you'd prefer they not when working together, but I can't really say how much of a problem that tends to be in practice.

[2oldman]

Is there an inverter in this mix somewhere? Do you dry camp?

If you're on shore with a charger you really don't need to have solar working with it.