Another Inverter & Converter/Charger Question

[Okotoks Camper]

Reading the topic on Charger Installation reminded me of a question that's been bugging me for a while.

I have a Progressive Dynamics 9000 series converter/charger and a Go-Power 1750 W Inverter. It seems to me that if I want to use my Inverter, my Charger should be unplugged/turned off. Is this correct? ???

John B.

 

[Bob Buchanan]

Reading the topic on Charger Installation reminded me of a question that's been bugging me for a while.

I have a Progressive Dynamics 9000 series converter/charger and a Go-Power 1750 W Inverter. It seems to me that if I want to use my Inverter, my Charger should be unplugged/turned off. Is this correct? ???

John B.

Yes. Otherwise, the inverter will attempt to supply AC to run the charger. That would run the battery down pretty fast.  I have my Statpower 40 charger plugged into a power strip that has an on/off switch. So it's inverter on, charger off. If on Genset or Shore, the charger is most always on.

When I was in my 5th wheel, there was another trickle charger in the converter. I was able to isolate that charger to a breaker that was easy to turn off when running the inverter.

 

[Okotoks Camper]

Thanks Bob, now I know why the microwave took twice as long to warm some beans as it normally takes. This was the only time I'v used the inverter as up to now, our camping buddies tend to be "full service" people.

In just fifteen weeks I will be retired. Quartzite 07, Here we come!! ;D

John B.

 

[John From Detroit]

Actually,,,, it all depends on how the system is wired... For example, when they installed the inverter in my Motor Home they did it half right (yup only half right, I'll fix it later) the inverter powers ONLY selected sub systems.  The front entainerment (And the accessory outlet down by the passanger's foot) the Rear entainerment, the Microwave and the GCFI (Bathroom, kitchen outlet , Dining area outlet, and outside outlet) it does NOT power the inverter, the Refrigerator or the air conditioners, they can be powered by the mains, but NOT by the inverter

What they did wrong was put both AC units on the same leg of the 50 amp service... I'll move it later

Actually.. I'll figure out what each remaining breaker does for it's living, do the math and rebalance the rig as best I can... This is really a very simple job

 

[Bob Buchanan]

Actually,,,, it all depends on how the system is wired... For example, when they installed the inverter in my Motor Home they did it half right (yup only half right, I'll fix it later) the inverter powers ONLY selected sub systems.? The front entainerment (And the accessory outlet down by the passanger's foot) the Rear entainerment, the Microwave and the GCFI (Bathroom, kitchen outlet , Dining area outlet, and outside outlet) it does NOT power the inverter, the Refrigerator or the air conditioners, they can be powered by the mains, but NOT by the inverter

What they did wrong was put both AC units on the same leg of the 50 amp service... I'll move it later

Actually.. I'll figure out what each remaining breaker does for it's living, do the math and rebalance the rig as best I can... This is really a very simple job

You make very good points, John. My rigs (4 now) have been equipped with a converter that also contained a trickle charger. My Tioga now has a much better charger but not of the output of the Statpower 40amp. So I have added an inverter and charger each time. Actually just moved the two units to the newer rig each time.

Each time I reinstall, I wire the inverter thru a double pole, double throw swith so AC to the converter is either shore/genset OR inverter. The Statpower 40 charger is then wired directly to the batteries. It is wise enough to know what to do there.

However, by doing it this way, the converter doesn't have a clue where the AC is coming from and sends AC/DC everywhere in the coach. I have been lucky with the breakers on the Tioga because they allow me to just shut down most of the circuits (air, microwave, converter charger, and such) without effecting the outlets I need during a dry campiing trek. In my other rigs, I had to do some breaker re routing to accomplish this.

 

[Karl]

Johb B.,

Your 'bean' problem might have bean (sorry, couldn't resist) the microwave itself. My Magic Chef oven does not take kindly to the modified sinewave output from the inverter, but works perfectly fine when on shore power or generator. And yes, the inverter is plenty large enough.

 

[Just Lou]

I just completed the installation of a 2500 watt inverter and a second set of 6V batteries in my '97 bounder.? I was able to alter the AC distribution/breaker panel to allow the installation of a second automatic transfer switch between the main breaker and the remainder of the feeder circuits to allow for the choice of inverter AC v/s Shore/Genset AC.? External or Genset AC will override the inverter AC and continue to supply the feeder circuits through the normally open points of the added tx switch.? The breaker panel was actually, and conveniently, constructed so that circuit #1 (feeding the Air cond units) is still only fed from genset or shore power.? I installed a convenience outlet near the converter, fed only by non-inverter produced AC.? I also installed a similar outlet for my new three stage charger.? When connected to shore power for any length of time I'll use the battery disconnect switch to prevent the converter from boiling the batteries but the new charger will stay connected.? So far, it seems to work as planned.? Since all circuits, except the AC units, receive AC from the inverter, when on, I'll have to be selective about which features I use.

I still have two unanswered questions that I need to check out.

Q1 - will my microwave work?? (the inverter is a modified sinewave compromise)
Q2 - My new charger says it defaults to Gel type battery when power is first applied.? Does this mean that I have designed in a requirement for manual intervention at every hook-up?

It's been fun.? Costly but fun.? Deep cycle batteries and 3/0 welders cable ain't cheap.

Hope I didn't bore anyone.? ? lou

 

[Karl]

Lou,

Not boring at all.

Q1 - No way to tell without actually trying it. You'll know immediately if it likes the mod. sinewave or not.
Q2 - Don't know what type charger you have. Some allow a permanent change to battery selection, others don't. The manual should tell you.

Now a question for you. I have a '96 Bounder and would like to add additional batteries. Where did you put them?

Added: Lou, if you have a 3-stage charger, it should go into float mode when the batteries are fully charged. Boiling them should not be a problem even if left connected and turned on.

 

[John From Detroit]

Q1 - will my microwave work?? (the inverter is a modified sinewave compromise)
Q2 - My new charger says it defaults to Gel type battery when power is first applied.  Does this mean that I have designed in a requirement for manual intervention at every hook-up?

It's been fun.  Costly but fun.  Deep cycle batteries and 3/0 welders cable ain't cheap.

Hope I didn't bore anyone.    lou

A1:  Maybee, It depnds on both the microwave and just how "Modified" that sine wave is... This is why I choose the inverter I choose (Xantrex Prosine line) Actually, I choose "pure sine wave", the dealer choose xantrex.

A2: Likely the converter will remember the settings you feed it,  There are three options here given in order of preference

A2-a: Converter will remember your settings so long as either 120 or 12 volts are applied to the proper terminals

A2-b: Converter will store your settings in FLASH RAM and remember them even after a complete power fail of both high and low voltage sides

A2-c: Converter will forget when unplugged (I can not imagine anyone designing one this way, but it's possible)

How to find out....

Plug it in, set it up....  Wait for the batteries to charge (No need to run them down)  Unplug.

Plug back in and check the settings,, Did they hold? if so good, proceed to test 2, if not bad, skip 2

Test 2: Now unplug it, and disconnect the batteries, Come back in an hour (it is amazing how much power those converters store) and don't forget to leave a 12vdc light on somewhere to insure it takes the condensers in the converters down to zero.

Either plug it back in or re-connect the batteries (or both) and check the settings... Again, did they hold, if so excelent, if not  well,,,, Keep the batteries charged

 

[Okotoks Camper]

Thanks for responses, even Karl's pun (Groan ;D).

I was originally trained as an aircraft electrician in the Canadian Air Force and reading through the solutions and ideas proposed make me realize how incredibly much I have forgotten. Once I get a chance to spend some real time in the fiver, I will look closely at the ideas suggested here, but right now they make my head swim.

Thanks again.
John B.

 

[Just Lou]

Hey Guys,

I've come up with a new question.  Before i could check my microwave for operation with  the modified sinewave inverter it (the microwave) decided to go on the fritz.  The key pad developed a problem.  Now my question.

Does anyone know of a microwave that will fit the typical 20" by 11" hole in an RV that WILL work with my inverter.  It's going to cost me less to replace the 'wave than the inverter, but I don't want to throw good money after bad.  TIA, lou

BTW.. Here's hoping y'all are having a fantastic time at the Rally.  I would love to make one of them someday and meet all the great folks in the framily.

 

[Karl]

Lou,

As far as I know, the Sharp m.w's work without any problem. Several people have them. The mfg's sites should have overall dimensions for their units.

 

[Gary RV_Wizard]

My GE Spacemaker convection micro works OK on modified sine, but its display goes crazy for a couple seconds when the inverter is first turned  on. Then is traightens itself out and seems fine thereafter. Think it must have some sort of internal regulator/filter that kicks in.

Remember that microwaves are big power consumers and will really suck your batteries dry. A small 600 watt (output) microwave typically draws about 1100-1200 watts input, meaning a 100 amp draw on the batteries.  With that large a load, the battery voltage will quickly drop below the inverter's low limit unless you have a large battery bank in good condition.

 

[Just Lou]

Thanks Gary,? I have added a second bank of 6V golf cart batteries for that very reason.? I will probably only use the microwave to warm up a bagel or stale donut once I'm on the road in the mornings.? ?But you just know I'm gonna put it to a real test in my driveway beforehand.

 

[Gary RV_Wizard]

I have added a second bank of 6V golf cart batteries for that very reason.

That should do the trick.