Different question on wfco

[cdcorpe]

I have a year old rv with 2 interstate cg2 232 amp hr batteries & had a 55 amp amp wfco converter. I called Randy @ best converters & asked about charging my batteries without running the generator all day , he recommend the boondocks'75 amp charger ( I have # 4 wire & less than 6 feet from converter to batteries) On our 1st trip we ran the batteries to almost 50% & after 1 hour of charging it added only about 10%( volts measured after surface charge)it never exceeded 13.6 volts , but it charged at 73 amps. I asked Randy & he said all was normal. Any Ideas?

[MEXICOWANDERER]

BFL, for years I have been convinced (though actual trial-and-error) that solar panels equivelant to 10% of total amp hour capacity offer just about the optimum balance of generator and solar. This is, of course, providing the skies cooperate and vacation is not during winter solstice.

My 3,300 amp hour bank would demand quite a number of panels to get me liberated from the Kubota or Lombardini. 330 amperes @ 28 vdc to be exact. Ten 33-ampere feeders to a buss bar. To say this is a little beyond my budget would be the understatement of the decade. Thankfully I have public power 70% of the time.

The bell-curve at this latitude allows an average of 5.5 hours with >80% theoretical max potential of panel output. Thankfully the bank is not stressed beyond 1,100 watts output counting MSW inverter loss.

Winning the lottery, panels, controllers and trackers would be nice...

[time2roll]

cdcorpe wrote:
Thanks , what should I look for in volts & amps, & the time for each the next time I run it down to 50%?

Immediate 75 amps same as before.
Should hold 70+ amps until converter voltage hits about 14.6+ after which volts and amps will drop.

Unless this is some new model that may hold the 14+ volts for some additional time.

[BFL13]

cdcorpe wrote:
Thanks , what should I look for in volts & amps, & the time for each the next time I run it down to 50%?

Same pattern as I posted earlier for my PM3 100amper, except for 75 amps on 232AH instead of 100amps on 458AH. You will still get that drop to 13.6 at about 70% SOC. Times will be similar to those in the 70amp on 220AH plot I posted earlier

When camping recharging by generator, just do 50-80s so you only do the 70-80 at the slower 13.6v. Even better, if you have solar going strong that day, just do a 50-70 on generator and shut off the gen when it drops to 13.6 from 14.8 then go on solar.

[cdcorpe]

Thanks , what should I look for in volts & amps, & the time for each the next time I run it down to 50%?

[BFL13]

Good news!

[cdcorpe]

Don't ask me how, because that is how I fix most things. I was removing the Power Max so I could install the old Wfco & noticed a 1/2 piece of plastic laying on the circuit board I removed it & decided to check output one last time & it was 14.8(at the converter) 14.7 at the battery. Thank everyone for their help in resolving this problem & hope that was it.

[BFL13]

Good picture! Hmmmm. I need to find out more about that product. Be a while.

[cdcorpe]

[cdcorpe]

[cdcorpe]

I checked the volts from the converter with the master switch off & the same 13.1 I have pictures of my Power Max , but I can't find out how to insert them here.

[BFL13]

cdcorpe wrote:
No, this one http://www.bestconverter.com/75-Amp-4-Stage-Main-Board-Replacement-_p_559.html#.VaBtGjY5JqM

Looking at the possibilities for product identification and specs some more. OP please clarify one more time, thanks!

The one you have is the one with the half open casing that goes in the lower portion of the power centre, and is not a deck mount with a full casing?

It says PMPC-75 on its label? No other model name ?

OP said his was not a Boondocker after all, but a straight PowerMax. How can you tell that? Note that PowerMax has the "PM3-75-MBA" but did not make a PM4 version of that.

Meanwhile, Randy sells a "second generation" version he makes, that is 4 stage that he calls PM4B-75-MBA, not a PMPC.

So how can you have a 4 stage one that is not a Boondocker? Seems impossible.

You might have received a PM3-75-MBA by mistake but it does have 3 stage and may or may not have the 15 minute thing (some later production PM3s do have the 15 min thing.)

But yours has some kind of 15 min thing and says PMPC on it, but acts like a single stage, and is (???) a PM not a Boondocker -again, how do you know that?

This should be possible to clear up, but the OP has to be very exact in his description (no typos! 🙂 ) and in the testing results to solve the mystery.

Once that is all clear, then it should be easy to resolve.

[BFL13]

What you really want is the adjustable voltage PMBC but it is a deck mount not a lower portion replacement. Then you could hold it to whatever voltage you like for as long as you like to save generator time.

No idea how you could trade that in now, unless it is indeed the old version without the 15 minute thing and you have proof you paid for the new version---but it did some sort of 15 min thing you said. VERY confusing! 😞

[cdcorpe]

I will try your test tomorrow. When I called wfco(before I bought the PW) They had me do the same test & it did & got 13.6 volts & they said that showed everything was ok, I asked about the 14.4 volts & got no good answer.

[BFL13]

cdcorpe wrote:
No, this one http://www.bestconverter.com/75-Amp-4-Stage-Main-Board-Replacement-_p_559.html#.VaBtGjY5JqM

Ok, so now we have a mystery. Meantime, at least you can do the voltage drop test described earlier.

It could be explained by saying you have the earlier version, which did not have the "15 minute thing" so would only go into boost if the batts were below 50% same as the WFCO. Later on, PM adopted the Iota type "15 minute thing" to get rid of that, so it would do boost at least for 15 minutes no matter what your battery SOC.

What we have here is a conflict between that idea and your report that it did some sort of 15 minute thing going from constant 74 amps to 35. The conflict is now that to do that the batts would need to be at 75% or whatever and not at 50%.

Back to square one. Batteries to 50% (for sure using voltage and SG) then converter to battery using short fat wires and time what happens.

(Idea being there might still be an "issue" with the connections/wiring as it is now, that we need to eliminate before declaring the unit itself is at fault)