Adventure with Battery and Generator

Tom_OC · 08-09-2015, 03:36 PM

Learned a valuable lesson while camping without hook ups this weekend. Always make sure your Generator is working correctly before you leave home. I made the dumb assumption that it was fine, only to find out that I had some bad gas and it didn't work. That said how long do most batteries last? I arrived at my destination on Friday at 2pm. By Sunday morning the battery was dead. It is only a year old and it is a RV/Marine battery. We did not over use things since my generator wasn't working as of Saturday afternoon. I kind of figured I would get through the weekend, but nope. Any thoughts?

P.S. DW would like to know if we should store our trailer with the refridgerator door open. It smells every time we pick it up from storage.

Murff · 08-09-2015, 03:53 PM

What trailer do you have? How big is your battery? If you dry camp frequently, you might consider replacing your battery for two 6 volt golf cart batteries. This will increase your capacity for your electrical. If you don't have them in your rig already, consider changing your interior lights to LEDs. The battery will also last mucho longer!

Murff

RedHorse1 · 08-09-2015, 03:58 PM

Fridge door open for sure.

Tom_OC · 08-09-2015, 04:08 PM

DW has already ordered the LED lights. Sounds like a good first step

clubhouse · 08-09-2015, 04:28 PM

With furnace, 24 hrs per group 24 battery. Without furnace, you might push it to 48hrs per group 24 with careful use.

We store with fridge door open

Chata · 08-09-2015, 06:58 PM

Same thing happened to me, I've plugged the trailer into the truck with the engine running for a half hour twice a day, went five days like this with a stock battery, refrigerator door always opened with a fridge off, no smell at all

Dgonc86 · 08-09-2015, 08:38 PM

Plug trailer into truck and it should charge your batteries while your vehicle runs

dewey02 · 08-09-2015, 09:37 PM

Something is wrong somewhere.
A battery should last more than just two days during the summer. Especially if you were being conservative. We have gone far more days and only dropped the battery down to the 12.1 volt range. During spring/fall if you are using the furnace, you will suck the battery dry in no time at all.

Was it fully charged when you began your trip?
Are the cells full up with water?
What appliances (radio, TV, lights, etc) were you using and how often?
A 1 yr old battery should be good, unless it was abused. Somewhere there is a problem, either with the battery, or with the amount of use you placed on it.

djtho1 · 08-09-2015, 10:46 PM

Typically, plugging into your tow vehicle won't give much more than a trickle charge. I have charged camper batteries by using a good set of jumper cables with heavy gauge wire. For your fridge, door open is probably a good way to go. I would also recommend cleaning it before storage with a cleaner, and maybe using either one of those Arm and Hammer baking soda things in the fridge and freezer, or, if you are cheap like me, some left over charcoal briquets in an old sock. Either will help soak up the odors.

As far as battery use, there is not yet enough information to determine whether the battery should or should not have lasted. Were you using a lot of lights? Did you run any kind of inverter from the battery, maybe for a fan? If you are doing a lot of camping without electric, I would recommend upping your available amp hours, either by adding a second battery, going with the two 6 volts, or swapping batteries out with a tow vehicle battery (I had a set up where I could charge a battery in the back of the truck while we drove around, then I could swap the low battery for a fresh one as needed).

Hohenwald48 · 08-10-2015, 12:23 PM

Incandescent lights will gobble up battery power. The refer and WH both use battery even on LP. Water pump uses a bunch if you run it for long. If you leave out the breakaway plunger the battery will be dead very soon. Some of the newer light fixtures have 20W quartz bulbs. Doesn't take many of those to kill a battery in a few hours. And having an RV/Marine battery label is usually just a label.

If you weren't purposely working at conservation you probably did pretty good on a single small capacity battery.

Subaru297 · 08-11-2015, 02:13 PM

Point of data for the truck charging. We have a Trimetric monitor installed and with the truck idling we had 4 amps going to the battery. Will take a long time to charge at that rate.

Read this and you will know more about batteries than you ever cared to.

https://handybobsolar.wordpress.com/...ging-puzzle-2/

We used to kill our group 27 130 amp hour battery overnight with a bit of furnace use. Charge with the generator the next day and do it again.

Now with properly charged golf cart batteries 220amp hours we might bring the batteries down 15% with heavy furnace usage. 85% is the lowest I have seen on the batteries all season. That is 33amp hours which is something our old group 27 should have easily handled. I don't think it was ever really fully charged to begin with and it was 1 year old as well.

Invest in a battery monitor and know for sure. Best mod we have done to our trailer.

Cheers

djtho1 · 08-11-2015, 04:14 PM

Subaru, When you are getting the four amps from the truck, was that through the trailer plug?

Subaru297 · 08-12-2015, 12:52 PM

Yes. Trailer was plugged into the idling truck and I was measuring 4 amps going into the battery. Sun was down so no amps from the panels.
I don't really recall but the battery was probably 90% or more charged as well so it could probably pull a bit more from the truck if it was discharged a bit more.
Really it is one meaningless data point. I need to do that test again a little more scientifically because many people think an hour of idling their TV will charge their battery back up.

But the truck would take a very very long time to get the battery back to 100% charge if it is possible at all with the voltage losses present over the long wire runs.
50 back up to 80% charge can happen fairly quickly but the last 20% or 10% takes a long time and needs voltages higher than the vehicle and sometimes even the converter will put out.

Cheers

djtho1 · 08-12-2015, 01:30 PM

That sounds about right, and really a little more than I thought was passing through the plug, so good to know. I should have specified more, but I was not wanting to make the post too long. Here goes:

When I was swapping batteries and charging them in the truck while driving around I ran a separate wire to the bed of the truck to get more amperage. I never measured it, but I could easily maintain my two sets of 6 volts by swapping them out every three days.

When I charged the batteries through idling a vehicle, I used a commercial set of Jumper cables that we hooked to the alternator and the ground post of the charging vehicle (in this case a Subaru Outback Sport) and then to the two dead (or nearly so) 6 volts on my father's camper. This charged them in about 12 hours, which we thought was pretty fair for a bastardized hook-up, especially since when we started the batteries wouldn't run the water pump or more than one light at once.

When you get further numbers, I would be very interested in them. It helps alot for future projects.

PNWDriver · 08-12-2015, 01:37 PM

We had the exact same experience when we first dry camped in our new trailer. We had left on a couple incandescent bulbs over night not thinking it would devastate our battery. We've since updated to golf cart batteries and led bulbs. Huge difference. We now use all the lights we want for hours on end and barely put a dent in our battery capacity. We also installed a battery monitor to keep an eye things.

Subaru297 · 08-17-2015, 08:47 AM

Got another bit of data from this weekends camping trip. The trip was a bit of a bust as the we got rained out but it happens.

Our 220 amp hour battery bank was discharged down to 88% in the morning that we were leaving the campsite. When I hooked up the truck and started it I did see 8 amps going into the battery with an idling truck. This was a bit more than I was expecting but the more interesting part is that when we got home the battery was only up to 96%.

After a 3 hour drive on the highway the battery charged from 88% to 96%. Approximately 17 amp-hours. It was very overcast and raining mostly so no real contribution from the solar panels.

Cheers

Bassdogs · 08-17-2015, 10:00 AM

No body talking about the gen issue and bad gas. Not sure what gen you have, but if bad gas was really your problem, you might have been able to get it back on line by draining the bad gas, including draining the carb bowl, and then refilling with fresh gas treated with a proper fuel treatment. Did you drain the gen after your last usage? Gas will go bad in as little as a month or 2 in storage. You should always drain or run the tank empty if you are not going to use the gen soon. 2nd, you should add fuel treatment to offset the ethanol in the gas. Ethanol will kill a fuel system if used untreated and for sure if left in the tank/carb during storage.

Always a good idea to test the gen at home before your trip just like all critical systems in your TT [fridge on gas, 12V and state of battery charge, PSI in tires, etc]. Easier to address before rather than after you arrive at an off grid site.

Single Regular deep cycle 12V marine battery is marginal at best for dry camping. Need 2 12V's or a set of 6V's are even better.

mike837go · 08-17-2015, 10:37 AM

Just some tips from someone who lives at the very edge of the power grid:

1) Run the genset under load at least 4 times a year.*
2) Keep a spare spark plug AND the tools to change it with the genset
3) FILL the crankcase with oil before starting Every...Single...Time...
4) Keep enough oil and gasoline on hand.
5) Disconnect the load from the genset before shutting it down.

At home, we don't have power failures often. But when the grid goes out (Sandy, Floyd, et al) we're down for days. So I keep our 5kw genset ready to go.

The 2kw I've used for boondocking get test runs through the winter.

*Running the genset under load confirms that all is OK, reinforces the residual magnetic field in the armature and flushes the carburetor of partially evaporated fuel.

I don't really know if shutting down a genset under load is bad. (I've heard that it is.) But I like to let the engine cool down a bit (and turn off the fuel) before shutting off the ignition.

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