Dilemma - which Converter-Charger needed

[IBTripping]

I want to upgrade the converter-charger on my 1996 24ft TT with a more efficient one that includes 4 stage charger, variable speed fan, low/high voltage protection, etc. I'm looking at 2 different Progressive Dynamics ones which have all the modern features. The 4100 model is rated at 35 amps and 1,000 watts. The 4000 model is rated at 45 amps and 725 watts. The 4100 costs a bit less. 

I don't plan to add much extra to the TT except for a couple of small TVs and replace the RV refrigerator with a small residential refrigerator. I don't think I'll ever be running many appliances at the same time. I'll be using two 6 volts golf cart batteries hooked in a series for 12 volts and 215 AH. I have a 2300 watt inverter generator for boondocking.

Is there any reason to get the 45 amp one instead of the 35 amp one?

 

[John From Detroit]

45 or 35 amp.> Well if you boondock the 45 will recharge the batteries a bit faster. But unless you suck like 40 amps from time to time no other reason....

I like Progressive Dynamics converters.  Not sure the variable speed fan is all that important though but hey. nothing wrong with them. THe fans do not bothe rme.  but might you and if so the vari-speed is less bothersome.

 

[Ernie n Tara]

Just an FYI; the residential refrigerator will actually save on electric use, however it doesn't have any impact on the converter unless you are running an inverter and even there I'd expect it to use less power (than the current one on electric).

Ernie

 

[Gary RV_Wizard]

The converter/charger is strictly a 12v device, so a residential fridge has no effect on 12v usage (unless you will power it with an inverter). Nor do most other RV appliances use much 12v - just their control circuit boards and that's trivial. The furnace fan is the only real exception to that.  The amperage values represent the combined 12v amps available for battery charging and 12v power usage and the charger gets what's left over after the RV's other 12v demands are met.  For example, with a 35A converter/charger, if 10A are in use to power other things then the charger can push up to 25A into the batteries.  As a rule of thumb, optimum charging amps will be equal to 1/4 of the battery amp-hour Capacity (shorthand is C/4). For your 215AH battery bank, that's about 54A. That will enable the batteries to recharge at the quickest practical rate; fewer amps will slow it a bit, though not a whole lot. The PD 4060 (60A) is more than sufficient, but the PD 4045 (45A) should do fine as well.

The max input watts on a 4100 is 550, not 1000. The 4000 is available in both 45A and 60A models, with max input wattage of 725 and 1000, respectively.

Since these are integrated AC/DC panels, make sure the one you choose has enough 120vac circuit breakers for your RV's needs. The 4000 has space for up to 7 breakers, while the 4100 is limited to 5. Also count up the number of DC circuits *fuses) needed - the 4000 and 4100 differ that way too.

 

[IBTripping]

The converter/charger is strictly a 12v device, so a residential fridge has no effect on 12v usage (unless you will power it with an inverter). Nor do most other RV appliances use much 12v - just their control circuit boards and that's trivial. The furnace fan is the only real exception to that.  The amperage values represent the combined 12v amps available for battery charging and 12v power usage and the charger gets what's left over after the RV's other 12v demands are met.  For example, with a 35A converter/charger, if 10A are in use to power other things then the charger can push up to 25A into the batteries.  As a rule of thumb, optimum charging amps will be equal to 1/4 of the battery amp-hour Capacity (shorthand is C/4). For your 215AH battery bank, that's about 54A. That will enable the batteries to recharge at the quickest practical rate; fewer amps will slow it a bit, though not a whole lot. The PD 4060 (60A) is more than sufficient, but the PD 4045 (45A) should do fine as well.

The max input watts on a 4100 is 550, not 1000. The 4000 is available in both 45A and 60A models, with max input wattage of 725 and 1000, respectively.

Since these are integrated AC/DC panels, make sure the one you choose has enough 120vac circuit breakers for your RV's needs. The 4000 has space for up to 7 breakers, while the 4100 is limited to 5. Also count up the number of DC circuits *fuses) needed - the 4000 and 4100 differ that way too.

Gary, thanks. You are truly an "RV Wizard."

But, you raise another issue I didn't consider. I'll want to run the residential refrigerator while traveling to my destination and while boondocking. So, I'll also need an inverter. Any advice on what I should consider in choosing an inverter?

 

[Gary RV_Wizard]

Since you will already have a converter/charger integrated with power distribution, I would stick with that design and add a separate inverter rather than trying to combine all those functions.  Get a pure sine inverter with a built-in auto transfer switch and it will handle the changeover from shore power to battery/inverter for you, which makes for a fairly simple install. Something like the AIMS 1200W model:  https://www.aimscorp.net/1200-Watt-Pure-Sine-Inverter-with-Built-In-Transfer.html.

 

[IBTripping]

Since you will already have a converter/charger integrated with power distribution, I would stick with that design and add a separate inverter rather than trying to combine all those functions.  Get a pure sine inverter with a built-in auto transfer switch and it will handle the changeover from shore power to battery/inverter for you, which makes for a fairly simple install. Something like the AIMS 1200W model:  https://www.aimscorp.net/1200-Watt-Pure-Sine-Inverter-with-Built-In-Transfer.html.

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[IBTripping]

Something like the AIMS 1200W model:  https://www.aimscorp.net/1200-Watt-Pure-Sine-Inverter-with-Built-In-Transfer.html.

Gary, Researched pure sine with auto transfer switch. You really know your stuff. The one you linked is the best option for me based on what I need, price, and quality product. When I get ready to install, I'm sure I'll come back to the forum to get help on proper install.

But, could you give me a brief overview of where I'll need install it in relation to the converter charger. Could I connect it to the TT AC system so it could be accessed from any of the TT's outlets? Or should I set it up to just be used for the residential refrigerator? I'm just thinking ahead that I may be someplace dry camping and need to plug in my CPAP which only runs on a few amps without starting up the generator.

FYI - Did more research and found there is a 45 amp upgrade kit to my TTs obsolete Magnetek 6300 (model 6332) converter charger which replaces the transformer with digital and replaces the lousy charger with a better 3 stage charger. There is also a Progressive Dynamics 45 amp upgrade with a 4 stage charger. I'll also have to replace the fuse plate if it isn't included in the upgrade kits.

My head is starting to hurt with all the new knowledge I need to learn for RVing. 

 

[Gary RV_Wizard]

You can power other things with the inverter, but that complicates the wiring changes more.  How much difficulty its adds depends on what circuits you want to move to the inverter and how the existing wiring is laid out, so I can't guess whether it is simple changes or horrific.  It also leads to the possibility of an overload, since any single wall outlet could be asked to deliver as much as 15A (1800 watts).  A microwave, for example, would probably exceed what the AIMS 1200 can deliver, and maybe also the size of your battery bank.

A standalone inverter has no tie-in with the converter/charger.  The charger is feeding power to the batteries via existing wiring. The inverter would have its own wires to the battery positive post and battery/chassis ground. About the only concern is to make sure the inverter output circuit is NOT the one that feeds 120v power into the charger, a serious no-no that creates a power loop.

 

[IBTripping]

A standalone inverter has no tie-in with the converter/charger.  The charger is feeding power to the batteries via existing wiring. The inverter would have its own wires to the battery positive post and battery/chassis ground. About the only concern is to make sure the inverter output circuit is NOT the one that feeds 120v power into the charger, a serious no-no that creates a power loop.

Thanks. I want to keep thing simple.

 

[Gary RV_Wizard]

The first thing to check is what is powered by the fridge circuit. Unlike at home, the fridge is often NOT on a dedicated circuit, so there may be other outlets or maybe even appliances sharing that breaker.  Depending on where you insert the inverter in the circuit, they may all move to inverter power. 

The simplest method is disconnect the fridge wire from its breaker and then run a wire from that breaker to the inverter 120v inlet.  Then connect the fridge power wire to the inverter output side.

I am a co-author of an article on the DIY RV site that shows some methods of adding an inverter to an RV.  Some of them require more than a little skill and planning, but maybe will be useful to you.

http://www.doityourselfrv.com/rv-inverter-install-diy/

 

[IBTripping]

The first thing to check is what is powered by the fridge circuit. Unlike at home, the fridge is often NOT on a dedicated circuit, so there may be other outlets or maybe even appliances sharing that breaker.  Depending on where you insert the inverter in the circuit, they may all move to inverter power. 

The simplest method is disconnect the fridge wire from its breaker and then run a wire from that breaker to the inverter 120v inlet.  Then connect the fridge power wire to the inverter output side.

I am a co-author of an article on the DIY RV site that shows some methods of adding an inverter to an RV.  Some of them require more than a little skill and planning, but maybe will be useful to you.

http://www.doityourselfrv.com/rv-inverter-install-diy/

That sounds like an easy to do approach. Also, thanks for the link. I can follow directions and usually figure out how to get stuff done from reading a guide. Thanks for all your help. I'm hoping to get the converter and inverter installed in January. I'll update the install progress.