Ok to run shore power without battery?

If your RV is sitting on a seasonal lot and never moves, you're fine without a battery. Having one will not change or improve anything. If you're towing or have slides that have to be moved in and out, you may need the battery for extra capacity but you don't need it to make the converter create clean power - at least not a converter from 2007.

No surprise the battery is no good. Wouldn’t hold a charge. Still unknown whether a bad controller overcharged it and killed it or I killed it by leaving it uncharged all winter and the controller just boiled it trying to charge it. For right now I’ll be running on shore power with no battery. Just for the next few days then shut the whole thing down for winter. Saw no point in buying a battery at this point. Thanks again for all the help.

Lead acid wet batteries get sulfated when left uncharged. The sulfur in the acid sticks to the lead plates and hardens on the plates if not knocked back off by charging...so yes, you killed the battery by leaving it in an uncharged state.

144Grayling wrote:
Thanks for all the information. The battery is a 12 volt lead acid RV deep cycle battery from Les Schwab. No reason to think it’s not what it says it is. As far as I know the only 12v functions in the trailer are lights, bathroom exhaust fan, radio and propane alarm. All those are fine on what’s coming out of the converter now: 12.9v No slide out, no hitch jack. Checking the panel it also has a few other 12v circuits that we don’t use ( dont need the water pump since we’re hooked up permanently, and the furnace, since we use electric heat instead of propane.) And it says the hood fan is 12v which I didn’t know. So everything we need is working fine off the converter and shore power. I don’t know why the converter was overcharging the battery to the point of boiling, but if it can go without a battery I really don’t need to care about it. I suspect that I killed the battery by leaving it outside uncharged over a couple of winters and that’s my bad. But, again, if I don’t need a battery in the system I’m ok. Still getting mixed opinions on that.

12V is needed for a propane/electric fridge (even on shore power) water heater (even on electric) usually for propane and sometimes CO detector

144Grayling wrote:
Thanks for all the information. The battery is a 12 volt lead acid RV deep cycle battery from Les Schwab. No reason to think it’s not what it says it is. As far as I know the only 12v functions in the trailer are lights, bathroom exhaust fan, radio and propane alarm. All those are fine on what’s coming out of the converter now: 12.9v No slide out, no hitch jack. Checking the panel it also has a few other 12v circuits that we don’t use ( dont need the water pump since we’re hooked up permanently, and the furnace, since we use electric heat instead of propane.) And it says the hood fan is 12v which I didn’t know. So everything we need is working fine off the converter and shore power. I don’t know why the converter was overcharging the battery to the point of boiling, but if it can go without a battery I really don’t need to care about it. I suspect that I killed the battery by leaving it outside uncharged over a couple of winters and that’s my bad. But, again, if I don’t need a battery in the system I’m ok. Still getting mixed opinions on that.

With that information, you don't need a battery. Your WFCO converter will take care of everything you describe.

ScottG wrote:
but you don't need it to make the converter create clean power - at least not a converter from 2007.

Good that you added "From 2007" as some of the older (Magnetek) you did need a battery or what they called a "Battery simulator" (Hardening capacitor is another name for it.. ONE HIGH CAPACITY Condenser like a farad or two) to clean things up.

144Grayling wrote:
The 12.9 was with the battery disconnected. (In fact the battery was at the NAPA shop miles away??) Looks like one vote for “it’s ok to run without a battery” and one vote for “you should put in a battery” Anyone else wanna break the tie?
And if I really do need a battery to protect the system should it be a deep cycle RV battery or a plain old car battery, knowing it will never be without shore power.

looks like your converter is fried. should be 13.6 to 13.7 with no battery hooked up. so, you likely need a new converter and a new battery

That may very well be true. But for now it serves our needs. This trailer is parked on our property to stay in during visits while we work on a permanent house here on the island. It’s a “bridge strategy” ( altho that bridge has gotten longer than hoped.) So as long as everything is working on 12.9 v (and it is) the motivation to put more money into it is pretty much zero. When we are done with it we’ll probably just give it away and the new owners can decide what to do.

Get a tiny cheap battery. For example:

https://www.costco.com/interstate-u1-lawn-%2526-garden-battery.product.100476412.html

StirCrazy wrote:

looks like your converter is fried. should be 13.6 to 13.7 with no battery hooked up. so, you likely need a new converter and a new battery

I'd need to haul some serious test gear into his rig to make an "Diagnosis" but.

13.6 volts DC is not the same as 13.6 RMS.

The old Magnetek 6300 Well if you read on the older analog volt meters the DC out was like 12-12.6 but if you read on the type of hardware I have you saw 18 volts (Depending on the device. I have both kinds)

so his 12 volts... might just be poor filtering of a supply with lots of ripple. Or it may be a very smart converter that says "Well I do not sense a battery so I'll go with the lower voltage"

Some I'm told do that. never seen one but that's not the business i'm in.

But if you are planning on running w/o battery by all means.
If it's a trailer you need to tow.. Use a battery tender on the disconnected battery. re-connect to tow
Or upgrade converter to a Progressive Dynamics 9200 series. (or 4600 if it's part of the power distribuition assembly).