What are these and why does everything still work??

[Civilguy]

Thank you Joe.

If I've got numbers right, this is a change from a 6300 series Parallax voltage converter that could produce a peak output from 25 to 45 amps (depending on the specific model) to a charger that is limited to 4.3 amps peak capacity.

I don't know how much of that 25 to 45 amps (300 to 540 watts) from the converter could actually be applied to charging the battery, but it's available to run 12V loads when AC power is connected.

Depending on your usage, this change could be very limiting in that even when AC power is connected you will be dependent on the battery for meeting any loads higher than about 4 amps (about 50 watts). And perhaps even loads under 4 amps if the charger's control circuit doesn't see enough voltage drop to respond and produce power.

Or, that might work out fine for you. I guess a lot depends on how large the loads are and when they are applied.

John published some measured electrical loads from his Escape trailer here. I ran across this when I was searching for the amps draw for my fantastic fan; it had run the little 35 AH battery in the teardrop down surprisingly (to me) quickly. Maybe it will serve to help project what your peak loads might be.

Just Finding Our Way: Scamp 19

Where did all our informed posters go? We might have to wait for the after-dinner crowd for the 'good' information.

[Dan Meyer]

Do you know anyone who is a ham radio operator or is into DIY electronics? If so, I'd bet they would be happy to re-install the capacitors into your converter. If you want to remove your converter and mail it and the loose parts to me, I'd be happy to repair it.

--Dan Meyer

[Keaner]

You won't you'll be able to run your unit on a charger. When charging a 12vdc lead acid battery, a typical charger supplies around 1.5-3 amps constant current, a lower topping current then finally a float charge current that can be as low as 100 ma.

A single 25w 12vdc bulb will draw 2.1 amps.

....Disregard..I didn't see previous, I thought you intended to run off a charger by itself.

[Joe & Cherie]

Originally Posted by Civilguy

Thank you Joe.

If I've got numbers right, this is a change from a 6300 series Parallax voltage converter that could produce a peak output from 25 to 45 amps (depending on the specific model) to a charger that is limited to 4.3 amps peak capacity.

I don't know how much of that 25 to 45 amps (300 to 540 watts) from the converter could actually be applied to charging the battery, but it's available to run 12V loads when AC power is connected.

Depending on your usage, this change could be very limiting in that even when AC power is connected you will be dependent on the battery for meeting any loads higher than about 4 amps (about 50 watts). And perhaps even loads under 4 amps if the charger's control circuit doesn't see enough voltage drop to respond and produce power.

Or, that might work out fine for you. I guess a lot depends on how large the loads are and when they are applied.

John published some measured electrical loads from his Escape trailer here. I ran across this when I was searching for the amps draw for my fantastic fan; it had run the little 35 AH battery in the teardrop down surprisingly (to me) quickly. Maybe it will serve to help project what your peak loads might be.

Just Finding Our Way: Scamp 19

Where did all our informed posters go? We might have to wait for the after-dinner crowd for the 'good' information.

Mike, this is great info!! The link to "finding our way" is very useful!

One thing I keep in mind is even that 25-45 amps from the converter to charge the battery - I cant use it at all because the converter will not work with my AGM. So I cannot use the charging pert of the converter at all. If the converter is installed, I actually have to be diligent to have the battery cutoff switch OFF so the converter does not charge it.

As for the watts I need vs what the 4.3 will charge - lets use the chart from the finding our way. I am omitting the AC items as they will be running on AC shore power, including any laptop or phone charging.

04.4 watts Dometic RM2620 Refrigerator
01.9 watts LED replacement lamp
15.5 / 23.3 / 33.8 watts Fantastic Fan
39.4 watts Standard water pressure pump

So Im draining the battery at 75 watts and charging at 50 watts (fan on medium and 5 lights on). But thats ONLY when the water pump is on. Once its off, I'm draining at 40 watts and charging at 50 watts. And if I dont have the fan on, Im draining at 15 watts and charging at 50 watts. So my battery should stay at 100%

Do I have this correct??

To your point tho - why not just fix it and then not be limited! Very good point!

Originally Posted by Dan Meyer

Do you know anyone who is a ham radio operator or is into DIY electronics? If so, I'd bet they would be happy to re-install the capacitors into your converter. If you want to remove your converter and mail it and the loose parts to me, I'd be happy to repair it.

--Dan Meyer

Dan, that's a very generous offer!! I sincerely appreciate that and its nice of you to take your time to help a newbie member. I'll let you know - I may take you up on it!

Thanks! Joe

[MarkyVasquez]

I would not recommend a battery charger for a converter. They are not filtered or regulated. Even when connected to the battery, their voltage is present on the Casita 12 volt system. The voltage can really vary on a battery charger. If you read the manual on the charger it'll tell you to disconnect the battery cables before charging. I've measured voltages as high as 18 volts on some chargers. They also put out a pulsating DC because they don't have capacitors to smooth out the DC. The battery will work to smooth out most of the Pulsating DC but if your battery ever goes bad any electronics in your Casita can be damaged.




Sent from my Nexus using Fiberglass RV

[Joe & Cherie]

Originally Posted by MarkyVasquez

I would not recommend a battery charger for a converter. They are not filtered or regulated. Even when connected to the battery, their voltage is present on the Casita 12 volt system. The voltage can really vary on a battery charger. If you read the manual on the charger it'll tell you to disconnect the battery cables before charging. I've measured voltages as high as 18 volts on some chargers. They also put out a pulsating DC because they don't have capacitors to smooth out the DC. The battery will work to smooth out most of the Pulsating DC but if your battery ever goes bad any electronics in your Casita can be damaged.

AH HA~!!! There is key info I needed and didnt know!! Thanks very much! So I should not charge while using due to these reasons above. Looks like I need to fix/replace the converter!!

Thanks Marky for saving me from disaster (just when I thought I was starting to understand this stuff.....haha!)

[Civilguy]

Originally Posted by MarkyVasquez

I would not recommend a battery charger for a converter. They are not filtered or regulated.

Thank you Marky. I guess I could have suspected there would be a reason for all those various bits and pieces in the chargers' circuitry.

I purchased a 2.1 amp 12VDC to 12VDC power supply to operate a little Coby TV/DVD in our teardrop trailer last year as the Coby didn't operate properly on the power from the progressive dynamics PD4000 converter. I clearly have a lot more schooling to do on this stuff and appreciate the help.

[David B.]

Joe, my CTEK 7002 has a mode in which you can run your RV on without a battery. Here is what their web site states:

CTEK Multi US 7002 Portable Battery Charger

The Multi US 7002 CTEK battery charger - CTEK's most universal, unique and technologically advanced smarter charger.

CTEK Multi US 7002 Portable Battery Charger Specifications:

For Use With: 12 Volt Lead-Acid Batteries (Wet, MF, AGM, GEL, and Ca)
Type of Charger: Fully Automatic - 8 Step Charging Cycle
Charging Current: 7AH Max
Warranty: 5 Years


The CTEK Multi US 7002 SLA battery charger (Part No. 56-353) is the ideal charger for your caravan, car and boat. The CTEK battery charger is well suited for all-year use. Thanks to its SUPPLY mode the battery charger provides power even without a battery. The SUPPLY mode is indispensable when changing the battery as you avoid losing complicated program settings.

The Mutli US 7002 portable battery charger is perfect for vintage car, boats with one battery, boats with start & service battery, boats with start & service bank, scooter, motorcycle, Quad/ATV, lawnmower, caravan, and tractors.

The CTEK battery charger includes two interchangeable connection leads, one with clamps, and one with eyelet terminals

Features of the CTEK Multi US 7002 Battery Charger
A great all-around universal charger
Fully automatic for charging and maintenance
Patented desulphation function
Compatible with other electronic equipment (no need to disconnect battery from application while charging)
Made for all weather conditions and situations
Designed for safety
Unique supply and recondition mode
8 step charging process

Dave & Paula

[John in Michigan]

Joe,

With my Trillium I decided I did not need to replace my nonfunctioning old converter with a new converter. The reason was that I was/am only using a few amps of 12vdc power. Here is what I did:

- Isolated CTEK charger and AGM battery as you have done. Battery is only online when boondocking.
- I use a SMALL AC to DC adapter to provide 12vdc power when the campsite has 110vac power.

Very simple and it works.

Note: Another downside to using the battery while charging is that the battery is being put through additional discharge/charge cycles, and thus won't last as long.

-John

[John in Michigan]

Joe,

And by the way using a CTEK charger that has a power supply mode is another great idea, but too late for me because I had already purchased a CTEK charger without that feature.

-John

[John in Michigan]

Joe,

With 8 LED bulbs and a LP detector, my 12vdc power needs are well under 2 amps. I have a $10 110vac to 12vdc adapter that I plug into a 110vac outlet I added inside the cabinet. If my 12vdc power needs increase, I will simply buy a higher output 110vac to 12vdc adapter. (12vdc circuit protection, e.g fuses, is still needed.)

When boondocking, I switch to the battery.

-John

[Joe & Cherie]

Guys, I cant thank you enough for all this. Before I started this project, I didn't completely understand the Casita how all the wiring works, etc. I was making upgrades without understanding the whole picture. Now, I believe I've got it!! I even understand how John a month back told me to use a STDP switch to go from converter to battery. (switching which one was going to power the DC panel). Now that I've dug in, took stuff apart, followed wires, and read what you guys said, it all makes sense!! The light bulb turned on!!

1) The 110 AC powers the 110 AC stuff
2) The 110 AC powers the converter
3) The converter converts 110v power and sends 12v to 12v panel
4) The battery also powers the 12v panel
5) The converter charges the battery

Its that simple! So with an AGM, I need to eliminate #5. I can use a simple adapter that John is talking about instead of #3. I also just eliminated of #2. I believe this is the simplest of all setups - what John has.

All that said, I now realize my charger could be better. A 7002 would have been better than my 4.3mus due to having more uumph, and its ability to use DC while charging. A simple converter like Johns can replace my converter.

What will I do now? Now that I understand how everything ties into each other, I will redo a "master plan" and ditch my big converter, rewire/switch in a simple converter and use a better charger, etc. This will take more planning, time, and $, so its going in the "to do in the future list". For now, I'm going to get the capacitors soldered on my converter and go camping!!!

Thanks again guys!!!

[John in Michigan]

Joe,

If you switch to a CTEK 7002 I think it has a supply mode, allowing it to operate as a power supply instead of a charger. If you switch to that, you would not need the 110vac to 12vdc adapter.

-John

[Joe & Cherie]

Yea, I thought about that to John. I may do that. But I may decide to keep the charge and the convert as two separate items for component simplicity. If the ctek quit on a trip, I'm out all my DC. Similar to the phone/answering machine combo, or tv/dvd combo. Never liked em!

I'm going to do some reading on specs etc and take my time designing the final deal now that I understand whats going on!!

Thanks for the thought!

added - I also want ability to be able to convert (simple converter) for DC usage, and charge battery at same time. Not sure 7002 would do that.

[Joe & Cherie]

Well, the end of the story! I bit the bullet and bought a Progressive Dynamics PD4655. I upgraded from Parallax 7345 45 amp to PD4655 55 amp by doing this. Randy at BestConverters said it would not be an issue to go from 45amp to 55amp. Now I can still charge my battery with the CTEK, but if I need a faster charge, I can flip off the CTEK and turn the battery switch on which will charge the battery from the PD4655. I installed it tonight. Went very well and everything works! If I ever sold the Casita, it will be good to have a nice functional charger/converter too. Yank out my battery charger and its all back to original!

Thanks everybody for your help!!

[Civilguy]

Originally Posted by JWScarab

Well, the end of the story!
Thanks everybody for your help!!

Congratulations, however this is not quite the end here Joe. After all your studies, you are now queued up to run the next class on this subject.

I've only gotten as far as receiving delivery of an intelligent charger (Battery Tender Junior). I still have the functioning Parallax in service as a converter, but figure that will be fine as I am shifting the battery maintenance duties to the new unit.

[Joe & Cherie]

Originally Posted by Civilguy

Congratulations, however this is not quite the end here Joe. After all your studies, you are now queued up to run the next class on this subject.

I've only gotten as far as receiving delivery of an intelligent charger (Battery Tender Junior). I still have the functioning Parallax in service as a converter, but figure that will be fine as I am shifting the battery maintenance duties to the new unit.

I might be able to do that!!!

Your setup seems simpler. I wish they sold just a converter w/o a charger function that bolts right in. I like simple.