B+ motorhomes

I have a cheap sears batt charger that does 2, 10, and 50 amp charging, and I don't recall if it's 13.8 V or a bit higher.

But if this simple cheap charger can be set to do 10 amps in an hour, can't the parallax?

In layman's terms (and I'm a layman): Not if the voltage is not high enough to push the amps into the battery. It is like filling a tire to 65 psi with a compressor only putting out 70 psi (takes forever), versus a compressor putting out 140 psi. Volts are pressure, amps are volume or quantity. Both are needed to put a charge back into a battery.

Further, charging at 13.x volts will lead to sulfation. Sulfation gradually diminishes the capacity until the battery is shot. The battery needs 14.4v charging, give or take, to remove each usage cycle's accumulation of lead sulfate from the plates and fully recharge it.

I think my WM dual cycle batt has a 70 Amphour storage, so within 5-7 hours of parallax charge at 10 amp/hr, shouldn't that fully charge the house batt?

The Parallax is a single stage charger. Its voltage is too low for timely charging, but too high for floating long term.

I have the 7355, which puts out 55 amps. But the voltage is the problem. It only puts out 13.8 volts, and who knows how much lower that is after going through 25' of #6 cable. To charge the battery quickly, it should get 14.4v in the bulk phase. A PD charger will charge the battery from 50% to 90% in a couple of hours or so. The Parallax might take a couple of days. :)

Batt charging amps/hr, I meant to say.

How many amps per hour does the Parallax put out a) on shore, and b) on genset power?

Good points. You've just solved my other dilemma about AC power source. As you suggested, disconnecting the Parallax charging wire and just using the add-on charger (my spare trolling motor charger) plugged into the coach AC wiring. I have an AC outlet beside the sofa (wired under the stove which is just aft of the sofa). This way I can just use the existing shore power cable and not run a separate extension to the TV just for charging. It helps to discuss this stuff! Thanks.

Orion,

The stock Parallax converter/charger is a poor one. Given enough time, it will boil your battery dry. For off season charging, a simple Battery Tender would be fine. And it would keep both batteries in shape together. I have three of them and use them on all sorts of seasonal batteries. They have never hurt a battery and never let me down. My batteries last a long time when kept up with a Battery Tender.

All that said, I'm going to change to a Progressive Dynamics converter at some point. I did that on my previous and current fifth wheel trailers. They are great. They charge the battery WAY faster, which becomes important if you are using the genset to charge the battery in a boondocking scenario. They have a true float mode like a Battery Tender and can be left plugged in 24/7/365 if you desire. They also have a desulfation mode to extend the life of the battery.

My decision will be whether to put a 4600 series into the Parallax chassis, replacing the stock guts, or mounting a standalone 9200 series under the sofa with a direct shot to the battery box below, and then disconnecting the Parallax charger. The shorter the cables, the better the charger works. I tracked down the charging cable in my current setup, and it is ridiculously long. They ran it over by the generator, then back towards the converter, then PAST the converter to behind the muffler, then doubled back into another of the black corrugated wire covers, finally heading towards the converter. I estimate they used 25' of #6 cable when the shortest path would have needed about 10'. That makes a big difference to the charger. Although all the tech guys say that a Progressive Dynamics is more able to deal with it than other brands.

The biggest hurdle to putting the converter under the sofa is finding a 120v line to power it. I haven't looked too hard, but I think I'd have to fish something up inside the refrigerator cabinet and into the overhead cabinet above the sofa. I'm not sure how do-able that is. If I was a serious boondocker, I'd have to find a way to do it. We hope to become more serious about boondocking in the future.

I hate leaving the converter/charger powered up all off-season to charge the house battery as I don't think it has adequate battery protection from overcharging. Plus it doesn't charge the chassis battery, though the Trik-L-Start you mention would solve that part of the problem. But then both batteries would be getting charged from that sub-standard charger. I do have a spare dual-bank trolling motor charger that I could wire in and it would separately trickle charge each battery based on their individual states. I just need to find a location to mount this so that I can easily plug it's power cord for off-season storage. These are premium chargers available from major marine and sports stores such as Bass Pro Shops.

Snowman, creative use of available materials on that repair!

I looked at the website for the Trik-L-Start. What a cool gizmo. It senses when the house battery is being charged, and diverts a little of the charging current to the chassis battery. $50 shipped, and would be easy to connect at the disconnect box.

Today I dealt with an issue that I saw mentioned way back in the early days of this thread. Namely, an improperly installed dinette. It turns out it's not that hard to get it right. Makes me shake my head at what was happening in the factory.

I have to look at the sofa too. The base is skewed out of square sideways compared to the seat. It looks like another installation snafu. I'm not sure if it is a quick fix or not. In any event I'm pretty sure the sofa is going to be replaced by a 32" bed. Not right away, because I've still got some basic things to work on.

Oh, also someone mentioned the floor collapsed in their kitchen cabinet. Same here. I tried injecting some expanding foam to prop it up, as was proposed in the original discussion. It worked so-so. I ended up gluing the loose floor edge up in place with epoxy thickened with sawdust. Being thick, I could shove it into the gap, then fillet over it. (Like a bead of caulk.)