WFCO Converter Longevity

Wayne Dohnal wrote:
Specifically, the PD meets spec with good wall power or an inverter generator.

I believe there are additional requirements for the PD to output full current.

1. The line resistance between converter and battery must be extremely low. 7 mohm total is good.

2. Battery resistance must be extremely low. AGMs are good.

In other words, current will taper (regardless of ac quality) if the dc voltage at the PD terminals jumps to 14.0V at the initiation of charging.

There have been many measurements made with an inverter generator. The PD tapers immediately.

For dry camping, my WFCO got retired.

I think the most I ever saw out of it was maybe 18 amps. That was on a single group 24 75 Ah battery. It never went in to bulk charge mode for me, ever. Not enough batteries.

It also never did a good job of topping off my battery unless I was in an RV park for a couple of weeks at a time, hooked up on a pedestal.

No thanks, I like dry camping a whole lot more. Along with an adjustable charge controller for my solar panel. Much better at topping things off.

I guess I haven't yet progressed to "Glamping", or "Glamour Camping" yet with all the bells and whistles. At that point, may as well just go get a room.

MrWizard wrote:
... If you have only one battery and no other loads turned on, that battery might take that 55 for a few seconds, before tapering down, ...

My 55 amp Iota will do just that, 55 amps for a few seconds.

I have one 100 AMP Battery, and monitor/test my system with a TriMetric Battery Monitor.

Wayne

MrWizard wrote:

kellertx5er wrote:

joeshmoe wrote:
Another thing I'm a little confused about is deep cycle amp. charging. I was under the impression that these deep cycle batteries are not supposed to never get more than 40-45 amps when being charged with the exception of desulfation mode. This WFCO converter supposedly spits out 55 amps. Isn't that going to eventually fry my batts?

Joe, the 55 (or whatever) amp rating of a converter refers to the DC output for powering your lights, refer, etc. It is not the charging current.

Wrong
There is one single output it will max at 55 amps
The battery is simply another load, like the lights and water pump
If you have multiple loads or batteries that can use the 55 amps it will be delivered to those loads

If you have only one battery and no other loads turned on, that battery might take that 55 for a few seconds, before tapering down, If you have several batteries with heavy discharge, they can and probably will take the full 55 amps

It's all about wire size and battery need (state of charge)

Correct except for the exact number of amps vs the rated max. Smk got more than his WFCO's rating and I got more the my converters' ratings as stated above.

The/a PowerMax guy told me their first batch of 100 ampers they got in from the sub-contractor that makes them would do 120a. The PowerMax folks thought that was a bit much, so they had to get "Engineering" to do more work on that so they would do closer to 100a. That got done. As it is, my 100 amper does 104a, which is "close enough" I would be very upset if it only did 99a of course! :) Seriously annoyed. So 104 is keeping me happy and PowerMax happy.

jmckelvy wrote:
Seven years and still working (except boost mode) on the one in my Northstar.

Ours is still working and is on its 7th season.

Dick

kellertx5er wrote:

joeshmoe wrote:
Another thing I'm a little confused about is deep cycle amp. charging. I was under the impression that these deep cycle batteries are not supposed to never get more than 40-45 amps when being charged with the exception of desulfation mode. This WFCO converter supposedly spits out 55 amps. Isn't that going to eventually fry my batts?

Joe, the 55 (or whatever) amp rating of a converter refers to the DC output for powering your lights, refer, etc. It is not the charging current.

Wrong
There is one single output it will max at 55 amps
The battery is simply another load, like the lights and water pump
If you have multiple loads or batteries that can use the 55 amps it will be delivered to those loads

If you have only one battery and no other loads turned on, that battery might take that 55 for a few seconds, before tapering down, If you have several batteries with heavy discharge, they can and probably will take the full 55 amps

It's all about wire size and battery need (state of charge)

joeshmoe wrote:

kellertx5er wrote:

Joe, the 55 (or whatever) amp rating of a converter refers to the DC output for powering your lights, refer, etc. It is not the charging current.

Ok. So it's power output, not charging out put. Got it.

Lots of great info. Keep it coming. Always learning new things here.

No it is amps output. However the amps have to be able to flow through the wires to the battery which means low resistance on the wires, and also the battery has to be "low" to have low resistance itself, so it can "accept" that many or more amps.

EG, my Parallax single stage 13.8v 7355 will only deliver about 40a on a low battery (12.2v say) because battery resistance is fairly high then. ( Very low resistance on the wires)

I have had it do 56amps along the same wires when I have the batteries down in the 11.x volt range by running a big 120v load on the inverter drawing 100a. With the converter trying to make up for that 100a draw it does its 56a just fine. So it really is a 55a converter.

With my 55 amp Paramode converter (RIP :( ) charging batteries, no other load, it did 62 amps constant for a while before amps started to taper with rising battery SOC. That was where the wires between the converter and battery were very short and fat.

My PowerMax 100amp converter is the same way. It does constant 104a charging batteries alone. The converter maker has to get the components just right to get exactly the rated output and no more, so normally they will do a bit more amps than the rated max. Also the input has to be good as Wayne said in order to get full output.

joeshmoe wrote:
I've been reading that these things are pretty much junk, don't last long. How long can I expect to get out of it? What should I upgrade to? For the time being, I'm thinking hooking up a battery tender directly to the battery. Suggestions?

Many trailers come with the so-called junk WFCO converter/charger like my new Windjammer. My old trailer had a bigger piece of "junk" Parallax converter that kept the batteries maintained fine for 9 years and never gave me a problem.

Just charging the battery (4x GC2) as part of a test. Initiated with a 10 amp load.

Test back in 2009 Back in the good old days :)