hooking up a charger to house battery

[pgandw]

My take on WFCO converters is that there are a lot more failures out there than one would think because most RV owners don't bother to check whether or not their converter is working correctly (taking voltage measurements).

If your RV is not plugged in when you are not using it, and you don't normally run your battery below 50% when the RV is in use, you will probably never know or be affected by a WFCO's failure to shift out of "normal" mode (13.7V).

In my case, I didn't discover my first WFCO failure until I ruined a set of batteries by letting the water level get too low. Once I started measuring the WFCO output voltage, I realized it would never leave normal mode for boost (14.4V) or trickle (13.2V) modes. I ended up replacing the entire WFCO 8935 with a drop-in PD 4135 panel/converter and was amazed at how much faster my batteries charged after dry camping, and how little water was needed during storage at home.

Knowing what had happened on my first A-frame, I started checking voltages as soon as I installed the 2 GC-2 batteries on the new A-frame. Sure enough, the WFCO never left normal mode (13.7V), even after being plugged in for 2 weeks with brand new batteries. Another PD 4135 converter/panel was purchased, and I've got a WFCO 8935P for sale or the trash heap (more likely).

I'm 2 for 2 with failed WFCO converters. I expect a WFCO not to perform to its own specs.

just my experiences
Fred W
2019 Flagstaff T21TBHW A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

[TitanMike]

Originally Posted by pgandw

In my case, I didn't discover my first WFCO failure until I ruined a set of batteries by letting the water level get too low. Once I started measuring the WFCO output voltage, I realized it would never leave normal mode for boost (14.4V) or trickle (13.2V) modes. I ended up replacing the entire WFCO 8935 with a drop-in PD 4135 panel/converter and was amazed at how much faster my batteries charged after dry camping, and how little water was needed during storage at home.

My guess is that you replaced the batteries when you replaced the Converter. If so, do you really know which was the problem.

Deep Cycle Flooded Lead Acid Batteries require far more maintenance as they use a lot more water than "Maintenance Free Marine/Deep Cycle" or AGM's.

[pgandw]

Originally Posted by TitanMike

My guess is that you replaced the batteries when you replaced the Converter. If so, do you really know which was the problem.

Deep Cycle Flooded Lead Acid Batteries require far more maintenance as they use a lot more water than "Maintenance Free Marine/Deep Cycle" or AGM's.

Not from my experience. In the post, I pointed out that the WFCO never went into trickle mode (13.2V). The constant 13.7V, even when fully charged, evaporated the water at a much faster than normal rate. Unfortunately, at the time, I never imagined the converter would not take decent care of my batteries.

Since replacing the WFCO with a PD converter, the batteries require topping off about once a year. Usually after a year, I'm about 1/4" below the ring in each cell. Proper voltages from the converter do make all the difference.

I learned about battery longevity back in the days of cars with generators and adjustable regulators. If you did all short distance driving, you wanted to set the regulator close to 14V. If you did a lot of long distance driving, 14V would boil your battery dry. Backing off the regulator to 13.6V was preferred for long drives.

just my experiences
Fred W
2019 Flagstaff T21TBHW A-frame
prev 2014 Rockwood A122 A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

[ScottBrownstein]

pgandw, that matches my experience with my PD 70 amp unit and 4 deep cycle batteries. Water maybe once a year...maybe not even that often. Many vendors have switched to PD out of the box and based on what I read on this and other forums, it is a good move.

[Steveboe]

If plugged in, why use a second source of charging? Unnessasarry.
I have used a charger instead of plugging in. Reason was the frequency of lightning storms and fear of frying electrical in the unit.

[kwindrem]

Depending on the chargers, you could exceed the maximum safe charging current when in bulk charge (constant current) stage. This of course is possible even with a single charger that's not set up properly.

I have found that leaving batteries on my delivery truck to discharge gradually when not in use can ruin them. I started using a trickle charger that includes a desulfator and battery life tripled.

The same issue could exist with house batteries even when plugged into shore power unless the charger has a desulfication cycle, or you add a desulfator. Many desulfication cycles use a very high battery voltage that could damage other equipment in the RV so use caution with selecting a charger not designed for RV use. The BatteryMinder brand uses a different algorithm and is available on all their chargers as well as a standalone desulfator that runs full time.

[camaraderie]

Pulse desulphators are snake oil and do NOT desulphate. They DO however provide a nice trickle charge which DOES show significant improvement in battery life for batteries which would otherwise self dischargee and sulphate.
Two VERY trusted E.E. friends set out a few years back to test all the popular pulse desulphators using standardized testing procedures and the very best equipment and concluded there were NO benefits to pulse desulphation either in battery life or in reducing existing sulphation.
What DOES work on lead acid batteries is high voltage Equalization cycles a couple of times a year AND to reduce existing sulphation. (Note REDUCE not eliminate!). A true EQ cycle should be performed at 15.5V, caps off and under temperature control (120degrees max) and a watchful eye. Continue until specific gravity measured starts to rise and then STOPS rising. Do not continue beyond this but you may put the battery back on standard charge. Best test of WHEN to do it is when a hydrometer test finds differences in cell values for specific gravity. Tedious but effective.
Modern 4 stage chargers (Progressive/Iota) have a built in and timed EQ function which is not as aggressive but is applied regularly and is effective and simple to maintain batts in good shape as opposed to fixing a heavily sulfated battery.

[popshumphrey]

Just to say thanks for all the posts. My take

It won’t charge faster
Let the house converter do its work

Thanks

[Jomo]

Ok this has nothing to do with this but!!! Can someone please tell me where the capacitors for a dometic ac unit are located. FR Cherokee. I'm not sure and I can't climb a ladder anymore. I looked behind the filter vent in the livingroom no go.

[A32Deuce]

Hate to tell you this, but up on the roof under the AC cover in a compartment inside the unit on the roof.

[Jomo]

Yea that's what I thought. A guy in the park told me that's what it was because the compressor kicks on and you can hear it. He has window unit in his and more screwed up than me.