Charging dead battery on Ford E350

ron.dittmer wrote:
Our E350 rig is kept in a heated garage. I have to disconnect the battery or the E350 will significantly drain it after a month. If I waited two months, it would not start our rig. If I waited six months connected, our battery would be dead as a door nail, unlikely able to bring it back to a reliable state.

I'm surprised at what you're doing above if you're talking about your engine starting batttery. Just plug your PC into a 120V garage wall plug, plug a $30 battery maintainer into a coach interior 120V wall socket. Then plug the output of the maintainer (using an adapter instead of it's alligator clips) into the cigarette lighter socket in the cab's dash.

Walla, the engine battery is taken care of 24/7/365 whenever you're storing your PC.

I've used a battery maintainer to trickle-charge a really dead battery (under 9 volts) up to a level where an old resonance charger could start working on it. This is sort of a desperation approach, with carries some risk (e.g. if the voltage is low because 1-2 cells are shorted out, a battery could overheat).

Most modern "smart" chargers have protections for some (but not all) potentially dangerous situations, they will tell you "bad battery" for a variety of causes.

Gjac wrote:

CodyClassB wrote:
Thank you all. I learned my lesson. I recharged the dead battery using the method mentioned above (jump started and recharge) . I also also install the Terminal Quick Disconnect Switch

Is that the one from HF, if so that green knob on mine loosed up and caused arching, the black burned contacts left me with a no start situation twice before I finally remove it. Now I just disconnect the neg terminal when in storage. As others have said there is a parasitic load, mine is about .4 amps which will drain your battery. I charged mine in Oct and disconnected after almost 6 months it is still at 80% SOC.

That is why I won't install any kind of convenient disconnect switch. Even though they are designed to handle the amperage, they have a much higher failure rate than if it was not there to begin with. It is much better to disconnect the negative ground terminal on the battery post, especially if doing it just once a year during the "Off" season.

Like everything in a motor home, you can add many nice features that introduce more points of failure. I ask myself, which ones are critical, which will be appreciated throughout the RV season, and which offer a rare convenience.

In this case, a total chassis failure is not worth any such risk. You may not think of considering a bad kill switch when you are dead on the side of the road. And if you do think of it, will you be carrying a spare to make the swap on the side of a highway? That feature is not worth the risk to me. The chassis manufacture, nor the RV manufacture leave it out for that very reason which is further cause-for-pause.

CodyClassB wrote:
Thank you all. I learned my lesson. I recharged the dead battery using the method mentioned above (jump started and recharge) . I also also install the Terminal Quick Disconnect Switch

Is that the one from HF, if so that green knob on mine loosed up and caused arching, the black burned contacts left me with a no start situation twice before I finally remove it. Now I just disconnect the neg terminal when in storage. As others have said there is a parasitic load, mine is about .4 amps which will drain your battery. I charged mine in Oct and disconnected after almost 6 months it is still at 80% SOC.

Thank you all. I learned my lesson. I recharged the dead battery using the method mentioned above (jump started and recharge) . I also also install the Terminal Quick Disconnect Switch

X2
I have a Black & Decker smart charger like that. It goes up to 16 volts if necessary to charge in a reasonable time; turns itself off so is perfectly safe to leave on overnight. I only saw that charger in a store once and bought it. Coincidentally we were staying with friends in winter and his car had a dead battery that wasn’t responding to his charger. I hooked up the new smart charger, put it on the 20 amp max setting and it started the car nicely in the morning.

Me, too, Ron. Disconnected, the E350 engine and house batteries stay a wee bit above 12.6 volts for more than a month.

There are SMART charger maintainers available from Schauer and others (but still shauer). They can DESULFATE batteries and then charge and if left on become a maintainer. I have used one on 'dead' batteries, desulfate, recharge and they were fine. These are not exactly cheap but well worth the prices. I keep maintainers on my batteries but in particular the engine. I have also replaced the free liquid batteries with gel cell which hold u better and dont go dry. Again expensive but last longer.

CodyClassB,

Did your rig sit out in subzero weather during the 6 month period? Around here near Chicago, this winter got to -30 degrees for an extended period. If that is your case, I would not waste any time with the dead battery because you won't be able to get it to do anything for you. It has been destroyed being discharged and sitting outside in such extremely low temperatures for so long a period.

Take the battery out and go to Walmart. They will sell you a decent replacement at a reasonable price. There is an expensive core charge on batteries. Bringing the old one with you saves a return trip to get your money back on the core charge.

Our E350 rig is kept in a heated garage. I have to disconnect the battery or the E350 will significantly drain it after a month. If I waited two months, it would not start our rig. If I waited six months connected, our battery would be dead as a door nail, unlikely able to bring it back to a reliable state.

Disconnect the negative (black, not red) battery cable when leaving your rig parked and unused for more than a month. If you don't want to do that, then start and idle the rig for at least a half hour every month. Running the engine heater while idling for so long will dry up any dampness accumulated inside the house.

You could buy a good battery charger and charge the battery every month. But that is more work. I feel the tiny thing you considered at Harbor Freight is not good for the application. It is intended to maintain a fully charged battery. Given your outdoor situation, you would have a power cord outside all the time. I am not sure that is the best situation. Disconnecting the battery when it is fully charged will serve you well.

Any charger that says "automatic" is not going to work. DAMHIK.

I had a friend who had an old style 4 amp charger. That doesn't care a bit if the battery is stone bone dead. I carry it.

I recommend adding a Trk-L-Start, and a modest solar installation.

I’m not a battery expert but I would not be comfortable going camping with a battery that had gone that dead. Buy a new battery and put it on a maintainer when leaving it parked for anything more than a week. Same for any late model vehicle; the Toyota mechanic warned us not to leave our year old Highlander parked at an airport for 2 weeks. It has a parasytic current draw of half an amp due to Toyota’s failure to use nonvolatile memory in the computer added to radios powered up to react to signals from the remote, current to keep the doors locked, clock, etc. I happened to notice that turning the headlight setting from auto to off reduced the current to a quarter of an amp - maybe the computer needed to be wider awake to decide of it was daylight or dark. I tried my best to inform the dealership but there was little interest in my discovery or my having to charge the battery several times a week all winter.

I have no problem with simply disconnecting the battery in our 2004 E350 for the winter. I’ve read that there may be consequences to disconnecting batteries in late model vehicles because they forget the aging of pollution sensors (EGR and oxygen) and they may have to be replaced so the computer can relearn their state from new. If so, a serious error has been made in design.