Converters-replacement?

[4winds]

I have no coach diagrams for my '81 Executive.  I know that they are all basically wired the same so,my question is:  How can I improve my system? Know that I need to upgrade my converter but I don't know what would be best.  All my books tell different stories and recomend different types of systems.  Help,please.  Ed i??

[TommyM]

How do you usually camp?  Are you usually plugged in while camping, or do you mostly dry camp?  If you dry camp, is it just for a day or two, or weeks at a time?  Do you have a generator? 

Anybody who gives you an opinion without knowing these things is probably just trying to sell you something.

Tommy

[4winds]

Will be mostly pluged into shore power,but will dry camp for a week at the most.  I have a 4kw onan generator.  Ed

[ibdilbert01]

To simplify this, converters have two functions.

1.  Charge and maintain batteries
2.  Provide power to the 12v system when plugged into shore power. 

The main difference in converters is the amp output and the way it charges the batteries.   The older converters were not very smart and just pumped out 13.4 volts regardless of  the battery type or even if the battery was charged.   This is fine if your using your RV and exercising the batteries.   However with this type of converter you wouldn't want to leave the RV plugged in all winter in storage as you risk the life of your batteries and could even boil them dry. 

The newer converters will taper back when the battery starts to get full and are much easier on the batteries.   Its very important to buy not only the correct size converter but also one capable of charging your battery type.

Lead Acid Deep cycles are the most common, and pretty much all converters are designed to charge them.  If you have AGM, Gel, or anything else you need to make sure your converter is compatible, as different batteries require different charging voltages. 

As for buying the right size, that gets a bit more tricky.    General rule of thumb for a Lead Acid battery (non smart converter) is 10% of the total batteries amp hour capacity.   Meaning, if you have a 100ah battery, a 10amp controller / charger would be recommended. 

The newer controllers are much smarter and you can get by with much higher amp models because of their design.  30 amp seems to be a common size and you can buy them much larger.   

I really like the IOTA chargers with IQ4, they seem to be pretty tough.

http://www.iotaengineering.com/12vdc.htm
http://shop.ebay.com/?_from=R40&_trksid=p3907.m570.l1313&_nkw=iota+charger&_sacat=See-All-Categories

[jkilbert]

In most coaches the lighting, waterpump, fridge igniter and furnace igniter (if electronic ignition ) and furnace motor run off 12v dc. So you need to examine your power needs. It's more of having storage capacity because you would need to run you genset all the time if you plan on running off of the converter.  i have two deep cycle marine/rv batteries to supply the 12v to all the lighting, etc. my stock converter acts as a charger when i'm plugged into 110v ac. my travel trailer is also setup the same way. in both my Winnie and Shasta the converter also acts as the main breaker panel for 110v outlets and fuse panel for the 12v circuits. Also don't forget that a few solar panels on the roof will also recharge your batteries thus extending your dry camping time without needing to run the gennie or the chassis to charge the batteries

[4winds]

Think I need a new converter as mine puts out 13.97vdc all the time.  Also need to replace the batt selonid as it doesn't work.  Converter is wired to coach side instead of house side.  Engine and house together.  Bummer.  Thanks for the help any more suggestions welcome.  Ed

[DaveVA78Chieftain]

If you want to think upgrade, then the first thing to do is determine if you have a new or old style converter.



The old style (70's era) is the one that can burn up the batteries.  There is a select relay (enrgized when AC power is available) that either selects the battery or the converter as the source for all 12VDC house power.

You want the new style because it maintains the house battery more efficeiently.  The new style acts more like a battery charger / alternator in that it's output is based on the current load requirement / battery condition.  It does not contain a selection relay.  The battery is always in the circuit (acts like the pressure tank in a well pump system at home).  The change over is not really hard as long as you understand the basic differences.

From there, you need to determine your battery capacity needs.  It is the amount of amp hours you need when only using the battery with no AC source (shore power / generator) available (i.e boondocking).

From there, you can decide how much battery you need.  Thats the high level jist of it, but there are several details in the execution.

Dave

[JDxeper]

This is the one I like  http://rvpowerpartsplus.net/index.php?main_page=product_info&cPath=10&products_id=47&zenid=76ada0728c26dde8a8a094e34e8930b1

This is a stage charger and distribution panel for both 12 and 110

If you get one buy the double pole breakers so you can have the 5 circuits(15amp) two 15/15 amp and one 30/15 amp.  The 30/15 double pole are hard to find. The 30 is for the feed.
JD