Dead Batteries when Boondocking

[garry.w.s.]

What should I do differentLy when Boondocking ?
We camped a few nights without shorepower. I disconnected the Chassis battery. I ran the Onan 5500 generator several times. Periodically I would run the chassis engine in order for the alternator to recharge our coach batteries ( My understanding is that charging the coach batteries using the alternator is much more effective than using the Onan generator.)Also to provide heat for us. We would occassionally run the water pump and of course the fridge was running on propane. Nights were cold ( 36 F ), so we set furnace on at 70 F. We have no gauges to show if our coach batteries are becoming badly discharged or not, so we just see if the lamps are dimming badly. In the morning we had dead coach batteries so we had to get boosted. We have 2 six volt deep-cycle coach batteries, quite new. What am I doing wrong or what should I try differently to have a better boondocking Xperience?

[rewaters49]

I don't know this from personal experience, but only from what I've heard: the furnace fan motor uses a lot of power and will quickly drain batteries. I do know this from personal experience - a generator will recharge a battery, but it will probably take two or three or more hours to do so.

[WheelingIt]

Well, I'd start by saying you need a way to monitor your batteries. It's the only way to know for sure how your batteries are functioning, how much power you're using and if you're managing to re-charge your batteries properly. The furnace can (potentially) draw down batteries fairly fast, and the generator may need to be run several hours each day to get a full recharge. It ALL depends on the state of your batteries.

Cheapest way is to get a battery hydrometer or voltmeter and check your state of charge. Generally you don't want to go below 50% discharge as it will age your batteries too fast. Much more convenient is to get some kind of monitoring system where you can see the charge inside the coach (on a monitor). We boondock quite a bit so we've got a Xantrex battery monitor. Another decent manufacturer is Trimetric.

[Wanabee FTer]

Originally Posted by garry.w.s.

What should I do differentLy when Boondocking ?
We camped a few nights without shorepower. I disconnected the Chassis battery. I ran the Onan 5500 generator several times. Periodically I would run the chassis engine in order for the alternator to recharge our coach batteries ( My understanding is that charging the coach batteries using the alternator is much more effective than using the Onan generator.)Also to provide heat for us. We would occassionally run the water pump and of course the fridge was running on propane. Nights were cold ( 36 F ), so we set furnace on at 70 F. We have no gauges to show if our coach batteries are becoming badly discharged or not, so we just see if the lamps are dimming badly. In the morning we had dead coach batteries so we had to get boosted. We have 2 six volt deep-cycle coach batteries, quite new. What am I doing wrong or what should I try differently to have a better boondocking Xperience?

Hi Garry and Welcome to irv2!
Sounds like there's a lot of seat of the pants dry camping going on there.
It's very hard to gauge your battery storage capacity without an amp/volt gauge and not knowing what your battery capacity is. Kind of like driving a long distance without knowing how much gas is in your tank. Only difference is, if you wait till the lights dim, (or in my example run out of gas) the batteries are being fully discharged and will be damaged in short order. A digital volt meter can help you monitor your battery state of charge.
I have about 375 amp hours of house battery capacity with a Xantrex prowatt SW600 inverter. The inverter has a digital volt meter built in so I can keep an eye on the house battery state of charge. Most deep cycle batteries should not be discharged below appx 60% (12.2 volts) Full charge is appx 12.7 volts. When I use my genset to charge the batteries I know when the batteries reach a certain voltage (13.7 for me) they are fully charged. If I'm using the engines alternator there is a different voltage reached when the batteries are full and yes somewhat faster then the genset.
My next upgrade will be a progressive dynamics PD9260 converter to replace my dated Magnetec 7345 two stage converter. The PD9260 is a 4 stage converter that will charge your batteries much faster on the gennie, and maintain them much more efficiently then a two stage converter. By adding a charge wizard pendent you will be able to set the converter to any one of it's four stages on demand.

[JayLodge]

If the 2, 6 volt batteries are your only ones for the "house", you are very underpowered for a 34' M.H. Whether 6 v, or 12, I would think you should have the equivilent of at least 150 a.h., and you probably have the rack space for twice that.
You can buy a nice 90 a.h. battery for the price of 2 or 3 campground stays that you aren't paying for when boondocking.

[wackymac]

My Fiesta came stock with 1 group 24 house battery. I now have 4 group 27 batteries. Look into adding more batteries. The furnace fan motor is HUNGRY. Try setting your thermostat lower at night.

[BryanL]

From what you are saying, the first thing to do is to get the charging and battery maintenance handled.

The Onan with a good charging device is the best way to charge the batteries - but keep in mind that it takes 8 to 12 hours to get a full charge into a battery and 3 or 4 or more hours to get a basic 80% charge.

A second issue is to get realistic on how little energy you have. Setting the furnace to 70F when it is getting close to freezing is going to run the furnace a lot. Using incandescent lamps also saps the energy supply.

Lead acid batteries have about 15 usable watt hours per pound of battery.

You've got maybe 120# or so of battery so you have about 1800 watt hours of energy available if the battery is fully and completely charged. The furnace runs at about 100 watts and a few lights can do that or more so you'd have 9 hours of lights plus furnace or less of energy available.

To get the most from your batteries, get a converter for your RV that knows about multiple stage battery charging and will also maintain the batteries when you are not using the RV by keeping a full charge on them and doing something to inhibit sulfation.

Don't run your batteries below 12.0v as tested with a decent voltmeter after they have had no significant charging or discharging for at least a half hour.

Do recharge batteries vigorously and promptly after use and make sure they get a complete and full charge and are properly maintained when not in use.

[az bound]

If you intend to boondock quite often I would suggest an automatic generator start system along with more battery capacity. Zantrix makes a good one, or the Onan Equanox. Both will automatically monitor and maintain the battery bank.

[doggod]

Originally Posted by garry.w.s.

What should I do differentLy when Boondocking ?
We camped a few nights without shorepower. I disconnected the Chassis battery. I ran the Onan 5500 generator several times. Periodically I would run the chassis engine in order for the alternator to recharge our coach batteries ( My understanding is that charging the coach batteries using the alternator is much more effective than using the Onan generator.)Also to provide heat for us. We would occassionally run the water pump and of course the fridge was running on propane. Nights were cold ( 36 F ), so we set furnace on at 70 F. We have no gauges to show if our coach batteries are becoming badly discharged or not, so we just see if the lamps are dimming badly. In the morning we had dead coach batteries so we had to get boosted. We have 2 six volt deep-cycle coach batteries, quite new. What am I doing wrong or what should I try differently to have a better boondocking Xperience?

A tool I wouldn't do without is my DC clamp-on ammeter. With one of those you can find out exactly how much current is coming out of or going into your battery bank at any given time.

If you know the AH capacity of your battery bank and the general condition (age) of the batteries, you can, knowing the discharge current, compute how much time the batteries should be giving you. If they're not giving you the computed amount of time, then you know you've got an issue with your batteries and can proceed accordingly.

With the price of fuel getting to where it is (and, even worse, where it's going as the Federal Reserve depreciates the dollar by printing trillions of new ones) it's going to be very wasteful to rely on your generator for charging your battery bank during the night if correctly-functioning batteries should have seen you through. Even new batteries would, if necessary, be money well spent.

To back up, a clamp-on ammeter is, as the name suggests, a device that measures current in a wire by clamping jaws around it, thus making it unnecessary to undo any connections. Traditionally, clamp-on ammeters were only available for AC, but technological advances have now made DC versions available too. You won't find these at Radio Shack, though, and they aren't cheap either. I use a Fluke Model 115 digital voltmeter, and Fluke makes a companion AC/DC ammeter, called Model i410, which plugs into the 115. One of the benefits of using professional-grade equipment is it also gives you access to plug-ins like this.

It's been too long and I can't remember where I bought these Fluke devices, but Mr. Google would surely steer you in the right direction.

[tomwalt]

Let me add to this - I found my refrig was using .5 Amps when running off propane (for the control board). That alone droped my batteries to 50% in just 3 days. When it is cold out, the refrig ckt. breaker goes off and I use a cooler. That allows the extra power to run the heat (at 60 degrees). A lot of times when it is in the 40 degree range I use the electric blanket to heat the bed up prior to entering, then I shut the heater off until morning when I use the heater and gas range for breakfast. However, the DW doesn't like having the heater off all night, but 65 degrees on the heater is acceptable to her.

[ralper]

Setting the overnight heat @ 70 F will use up all of your power fast. Two 6 volt batteries = 225 amps. of which 50% (112.5 amps) is available to use without destroying the batteries. 1 - furnace blower = 9 amps per hr. That gives you 12 hours of blower operation on the fully charged batteries you now have.

Set the heat lower at night. I do not use heat overnight unless the outdoor temp is going below 45 F.

Get an automatic control to start the generator when the batteries go low.

Get set up with 4 or 6 batteries.

Use an auxilary heat source. One without an electric blower. Propane brick heater maby.

Consider a solar electric system of about 400 to 600 watts. Rule of thumb is 100 watts of solar panels per battery. If you are interested in solar read my post "Solar That Really Works."

If you buy more batteries, replace the ones you have now so they are all the same age.

As already mentioned buy a battery monitor and set it up correctly for your system. Trimetric is very good. Then you will always know the state of your batteries. You will never know without instrumentation. You have experienced that.

[leadman]

An inexpensive and easy way to measure the battery voltage is to buy a device that plugs into a cigarrete lighter. I have a digital device that has multiple lights for charge status and a digital display of the voltage. While not as good as the other devices mentioned, it is inexpensive and gives you a good idea of battery voltage.

Think mine came from Walmart.

[SteveLevin]

You should have no issues with what you described and 2 good batteries. I was just down at Pismo Beach under similar use (i.e., running the furnace at roughly 70, so it was on a decent bit of the night, fridge, and even charging phones/laptops/tablets using a small inverter), and I ran the generator once for about 3 hours, and I'm not positive I would have needed to do that... but since I just have a Green/Yellow/Red set of battery indicators, and they got into the yellow, I figured it couldn't hurt to charge them up.

Steve

[dzmiller]

Originally Posted by garry.w.s.

.....My understanding is that charging the coach batteries using the alternator is much more effective than using the Onan generator.........

No, it will likely only charge the starting batteries well. You may need to run the Onan several hours each morning. The biggest conservation change you can make is to switch to LED, and leave the inverter off when not in use. You need to know the voltage of your house batteries when under little or no load, and keep that voltage above 12.0.
In a mid size or larger RV two batteries and no solar isn't much capacity for boondocking. People who do that successfully conserve and manage power. At a minimum need to measure voltage to do that.
It's expensive to run batteries below 12.0 volts. Be aware of the degenerative cycle of over draining batteries and reducing their capacity.