Converter or charger

[Elumia]

I have come to the conclusion it makes sense to only have 12v lighting - seems most modern RV's are that way too.

I am retrofitting an older 10' canned ham - rebuilding it. I am planning on having 4-6 lights, possibly a 12v fan (maybe just a vent as it came). I own a 400w inverter for those times w/o ac power and I will put in a 12v outlet for recgarging the cell phone etc. I plan to also put in some minimal AC power (looks like a std 30A breaker box is cheap and easy)for a couple outlets and a method to recharge the battery. No refrig, just orig icebox, Gas stove.

I've found a 105 Ah deep cell (lead acid) battery at Tractor supply for about $65, seems big enough.

So, the question is...

I'm on a budget!

Do I get a converter to supply constant 12v and recharge the battery or is is sufficient to just add a battery charger? Obviously less $ to just get a battery charger but then I have to manually keep on the charging process. Is there a solar charge controller that would charge the battery via solar panel or AC?

Thanks for the help.

Mark

[Chuck Craven]

Hi Mark!
I looked at converters and they looked a little power hungry to me! By the time I found one that was small enough for my needs it took to long to charge the battery.
The battery chargers seem to be the best and easiest to work in with out spending lots of doe. Take a look at the three or four step chargers.
As for solar you can build your own controller for a reasonable price but you will have to go to e-bay to get a good price on the solar panels. If no sun no charge! So it seems one still needs the charger any way.

My approach is to have a battery charger in the camper use as little power as possible. Like led lights and gas stove, ice box and gravity water system. Have a second battery in the car charged with a dual battery isolator for when I can’t use AC power to keep the campers battery charged. Both the camper’s battery, the second battery in the car will be the same and interchangeable.

Chuck

[len19070]

I always run a charge line from the tow vehicle to the trailer. Battery charging is a no brain'er then. When you tow the trailer and are plugged in...your charging the battery. Basically when you drive to your campground, your charging. This is a minimal cost. You have to buy at least a flat 4 wire harness for the trailer both ends. Buy a male & female 7 prong plug, that will accommodate a charge line instead. I'll bet the difference is only about $5. Between that and the cost of a piece of wire to run the length of the tow vehicle. and the entire project is only $10-15.

Another good feature about running a charge line. If your out camping and your trailer battery goes dead from use, just plug the trailer into the tow vehicle and start the engine. You have the option of charging in a remote area. How long the engine runs determines how much charge.

Also, converter chargers aren't that expensive, look up ebay item number

#4551488102

http://cgi.ebay.com/ebaymotors/ws/eBayI ... AMESE%3AIT

I have used these often. Once again, a no brain'er. When your plugged in..its charging.

Hope this helps.

Happy Trails

Len

[madjack]

...I think a 3/4 stage charger is the way to go...I like the 5/6amp Deltran model or Wally World sells a 25 dollat cheapie under the B&D brand name made by VECTOR...be wary of car charging or a convertor that is simply automatic...they will work fine for most ocassions but may leave your battery short of charge on an extended stay without additional charging available...
madjack

[GeorgeTelford]

For Marks original Question

I am with MJ get a staged deltran charger, this will supply your needs and charge the battery, cost difference is not more than a few dollars

Len

Charging via a charge wire, maximum that this will charge[/b] the battery to is 70% ish full, so say you have a 100 Ah battery that means max is around 70 AH take away the 50 AH you should not use and you now have only 20 AH to play with.
What is even worse is that if you fully charge the battery via a staged charger, then [b]charging via wire actually loses charge on the way to your destination....

I measured this once by fully charging a battery With a Sterling charger and then discharging with a bulb until 12.2 Volts registered and noted the time

I then repeated the test, but this time after fully charging I attached the battery to a "wire charger" and drove around for over an hour, the measured discharge happened over an hour quicker, where had that charge been lost? there is only one answer...

I did the above test after noticing something strange on my regular camping trips, initially my campervan did not have wire charging and was charged on shore power at home (virtually every camping trip was in boonies so no shore power)

The battery always lasted the weekend without problem (even long weekends) this was running lights TV etc.

After about a year I decided to add wire charging, the very next weekend the battery ran out early and the following weekend, so I removed the wire charging, next 2 weekends no problem, hmm strange checked everything out no problems tried again same results.

[Nobody]

George, is the 70% line charge from a vehicle alternator always the case, or is there a method by which the charge may be increased to approx full?

I ask because I have an old 1985 Ford diesel with dual batteries & an (I believe) 105amp alternator. For about 10yrs, late 80's thru mid 90's, it hauled a very large (approx 3000#, 12' box, side entry door) cabover camper. When I first mounted the camper, I had a charge wire going directly to the power converter/charger from my truck alternator. The camper had a Group 27 deep cycle battery. Had no problems until I spent a week at hunting camp in relatively cold weather once. The furnace cycled frequently, along with normal lights, water pump, fridge spark, etc. At the end of several days, I found I'd nearly drained my truck batteries (they wouldn't crank the engine) but the RV battery still contained a weak charge of around 12v (it would still cycle the fridge spark, furnace blower, & lights). Had to drive my 'towed' vehicle home with my truck batteries for a charge (the battery in a '77 Datsun P/U won't 'jump' a 6.9L diesel when it's 18*f).

Next day I had my son bring me a Dual Battery Isolator from his NAPA store. After wiring it into my truck elect/charging system, I replaced the single deep cycle battery in the camper with a pair of Group 29 RV batteries wired in parallel. From that time on I never experienced any problem from the truck batteries, & have spent as many as 7 days 'boondocking' in the camper without starting the truck to charge the RV batteries. After a couple of checks, I found that the first battery in parallel would discharge a little quicker than the second. I made it a habit to 'rotate' their position every couple of months, & even with frequent use of the camper (every couple of weeks or so, for at least a weekend) the batteries lasted about 5yrs before needing replacement.

Think I installed the DBI about 1989/90 so it's been a while & I no longer have the box or instructions. It is quite a large, solid state DBI & the only visible mark on it other than the connector post ID's is "CG-130". Seems I remember something either on the box or in the instructions about it being an auxillary charge controller as well as isolator?? In any case there are 3 contact posts, one wired to the alternator, one "MAIN" connected to the three wires that originally came from the alternator, & one "AUX" to the camper converter.

Guess my question is, did the DBI provide a more complete charge to my camper batteries, or was I just fortunate with my aux battery choice/power usage? I did, quite often check the RV batteries' charge level after a day's drive & they most always showed in excess of 13v on my digital voltmeter. I'd think that was pretty close to a full charge.

[GeorgeTelford]

Hi Nobody

How long your battery lasted is a relative measurement, it all depends on your power usage.

I believe a dual battery Isolator is a relay, ie all it does is seperate the battery positives when the vehicle is switched off

Any battery when taken off "charge" will show 13v (even when you switch the alternator out the battery will show over 13v ) it is only rested voltage that counts ie you need to measure after 12 hours after charging finished.

You asked "Is 70% always the case?" no experts the world over are concluding that 65% is generally the best that can be achieved via an alternator.

You also asked is there a method by which the charge may be increased to approx full? Yes either make yourself a manual alternator control or buy a smart regulator to turn the alternator into a 4 stage charger.

Here is the one I have and some extra information

http://www.sterling-power.com/htm/ar12vd.htm

Here is a section of a book by Collyn Rivers, a free chaptor at the bottom of the following link

http://www.caravanandmotorhomebooks.com ... ns_too.htm

[Nobody]

Thanks George.