Computer Power Supply as a converter substitute

[GuitarPhotog]

I am convinced that the battery charging will best be left to conventional charging means, but I still think I'll get a CPS to run the 12v lights and fans when 110v is available, to lessen the usage of the battery. Of course I'll have to have a battery disconnect when the CPS is being utilized, but no problem seen there. I guess that if something looked that easy to do, I would've heard about it before now!

So, if you are going to have a battery charger also, why bother with the computer power supply in the first place? Why not just use the battery charger to charge the battery and to supply 12VDC for accessories when shore power is available?

Why use two devices when one will suffice?

<Chas>

[working on it]

GuitarPhotog wrote...

So, if you are going to have a battery charger also, why bother with the computer power supply in the first place? Why not just use the battery charger to charge the battery and to supply 12VDC for accessories when shore power is available?Why use two devices when one will suffice?

I know that's the logical way to go, but I was thinking of a 20 amp or larger capacity charger for the battery, and < 10 amps draw for the fans & lights. And the CPS is much quieter than my big charger. K.I.S.S., I guess, would be best. I will look around for a compromise size charger.

[working on it]

deleting double post

[Dale M.]

I am convinced that the battery charging will best be left to conventional charging means, but I still think I'll get a CPS to run the 12v lights and fans when 110v is available, to lessen the usage of the battery. Of course I'll have to have a battery disconnect when the CPS is being utilized, but no problem seen there. I guess that if something looked that easy to do, I would've heard about it before now!

I don't think this is really an issue....

Many backup power systems used in telecommunications ( cell phone sites/ fiber optic regeneration sites / phone company switching system) use a setup where rectifiers (battery chargers/power supplies) and batteries and discharge (power to apparatus) is tied to one set of COMMON bus-bars, meaning batteries are always at state of full charge, and any load changes and what ever are actually carried by rectifiers (battery chargers)as long as commercial power (or back up power generator ) is there to power rectifiers.... You do not wear a battery out by not using it, it dies from lack of chemical action/reaction and recharging.....

You need to go read battery FAQ on design/construction and charging techniques of batteries to see why its actually better to use battery and keep it fully charged then to let it sit with no "action" taking place...

The "system" of battery in a state of fully/constant charge and discharge used by telecommunications industry allows them to get 15 to 20 years life on a set of batteries, granted they are more robust and better quality than a "car" battery but concept is the same, and you are investing is two power supplies when only one is needed so its extra cost, and you also have to switch over system dependent on what shore power situation is, where with one charger and everything always connected its sort of automatic because it is always there and never changes, unless you have situation where you can not recharge battery... ( see charging while towing)...

While it all sounds good in theory and yes it will work in your way, it violates the KISS principle(Keep It Simple Stupid)...

Dale

[working on it]

Actually Dale, I'm in agreement with you. I made a long, drawn out post the other night to explain why I've discarded my CPS usage plan, gone to a conventional battery / charging relationship (using the battery constantly; using shore power/generator power for A/C and powering a conventional charger, only). However, the ghost in my machine first double submitted it (see the post prior to yours) then double deleted it. I responded to that with my INTERNAL (infernal) SERVER ERROR rant?!http://www.tnttt.com/viewtopic.php?f=26&t=52647 Among the lost info was the fact that since the battery and inverter will be used 90% of the time , and the battery will be needing topped-up power occasionally, I chose to get a reliable charger/maintainer suitable for my AGM Optima Yellowtop battery (automatically tapering the charging rate). The Schumacher XCS15 has an AGM selection button that will allow me to set and forget the constant monitoring that a CPS as charger would require, I had used an expensive racing battery years ago, which I cooked to death using a constant rate charge (neglected to keep tabs on it, just one time, very expensive lesson,cost me a race also). I appreciate your reply, and yes, I was adding an unneccessary complication to my trailer. And, I have the new charger in a quick-disconnect harness, so I can use it elsewhere if needed...for about the same price of a dedicated (and wrongly purposed CPS).i also had refined my plan and outlined the revisions in another post a week before (coincidentally also wiped out at least once by iNTERNAL SERVER ERROR, A picture of my power panel :

[trainman129a]

Another problem with a cps is that the outputs are not separate. They all have a common ground/neuteral. They cannot be ganged togetyer to increase the output voltage.
The example above was to take the 3.3 volt and add it to the 12 volt output to get 15.5 volts. I don't believe it's going to work.