Battery Life on a trip

[Raspy]

Originally Posted by Lynn Eberhardt

People used heat to cook food for centuries before microwave ovens came along. Going back to that can be part of the camping adventure. A buttered frying pan even makes decent toast. Have fun with your creativity.

Wait a minute! Aren't we supposed to have every conceivable convenience appliance when "camping"? Isn't camping supposed to be the same as being at home? It seems the value of being out in the wild is lost when all we care about is running the AC and the microwave.

[JaxDan]

I like WaltP's suggestions and thinking of possibly doing the same trip sometime soon (I already have both COVID shots) there are some things I have already considered. First, since I live in Florida and use a CPAP without a reservoir I already have a small AGM battery that when charged will allow me to sleep 4 nights during a power outage. I have a charger for the battery that can run off an inverter in my SUV while on the road.

Also, in other areas of discussion a propane powered inverter generator was mentioned which would handle many tasks including keeping up a battery. Propane burns cleaner so the exhaust smells better and storage of the fuel is safer than gasoline in Jerry cans.
Good luck finding a solution, if you travel in summer you may find your vent fan gets a lot of use.

[computerspook]

Even without a humidifier my CPAP quickly drains the batter. And I have a good one. And try it without the humidifier. You probably will decide you need it.


I use a generator. Got one from sams and it works great. Last time I looked they had the model I have (the inverter one) on sale.

[mariaandskip]

A little off the subject but I too was tied down to a CPAP machine but traveled to places with no electricity. I went to my sleep specialist and got fitted with a dental appliance that re-positions my lower jaw. No more mask, hoses or electric cords. I can talk and drink with it in and my wife says no more Darth Vador at night

[Yvimij]

I often go a couple of weeks without plugging into shore power. I carry a Honda generator to run the AC, a Yeti 400 Power Station with a 200-watt solar panel (that I seldom deploy unless I will be in the same spot for several days), and a car battery starter that will let me jump-start my tow vehicle if needed. I also carry a shirt-pocket sized powerbank that will charge my phone or laptop in an emergency and serves as a handy LED flashlight.

I only use the trailer battery for the led lights, the Fantastic Fan, and the furnace when needed. Of course, the trailer battery charges while I am driving. The Yeti runs my Cpap and Dometic 12v freezer overnight. During the day, the Dometic runs from a 12v outlet in my tow and the Yeti recharges while I drive.

I check the charge level in my batteries often. I figure that the worst that can happen is that I have to stop by an auto parts store and purchase a replacement battery for my trailer.

[thrifty bill]

Originally Posted by Wynn

Some walmarts are putting up signs for no overnite parking. I live in the ST Louis area and travel to colorado and florida yearly, i stop at Loves or Flying J travel stops, i have always backed in with the 18 wheelers and never had any problem.

!

I overnighted at the Flying J in Limon, CO on my way home in 2019. I was happy to see they had RV parking next to the car fuel pumps and truck parking on the other side of the facility. I always have tried to save truck stop parking for the professional drivers, that do it for a living and buy 100s of gallons of fuel.

I was surprised when I woke up in the morning, and I was blocked in by many, many semi trucks that parked in the RV area. Oh well.

Goodland, KS Walmart is a great stop very close to the CO border. I've overnighted there several times.

[James V]

Do not use fans including heater. This will extend battery life. Get a solar panel. Pray for sun. Expect to move after 36 hrs. Maybe 3 days. Do not know about crap.

It is a new game. Play it well.

[Borden]

We have a m31 gel pack; better than marine deep cycle but still have to go light on power. The stove and has no electivity requirement, furnace needs safety systems and fan, water pump (big drain), hot water tank uses some for safety systems, even fridge needs some pwr even on propane, lights should upgrade bulbs to led they can put a drain on our time. The car will not keep up with needs and solar panels are not light. We new just stick to campsites with pwr.

[Glenn Baglo]

Originally Posted by mariaandskip

I went to my sleep specialist and got fitted with a dental appliance that re-positions my lower jaw. No more mask, hoses or electric cords.

I'm new to this, but I think a CPAP does a lot more than silence snoring. I'm hoping that turning humidifier off and charging with solar and a generator ( if necessary ) will get me through.

[John in Santa Cruz]

when its ~40F out and I have my furnace set for 65F inside, my E21 classic w/ the extra insulation package only runs the furnace about 5 minutes at a time, maybe 2-3 times an hour, so if that furnace is 2.8 amps (just going by what someone above said), thats between 0.5 and 0.7 amp*hour per hour. If I heat for 10 hours thats 5-7 amp*hours. for 20 hours, thats 10-15 amp*hours a day.... with my dual flooded golf cart batteries I have approximately 110 AH of available power before the batteries are at 50%.

so I don't get what the problem is here.

[Civilguy]

Originally Posted by John in Santa Cruz

when its ~40F out and I have my furnace set for 65F inside, my E21 classic w/ the extra insulation package only runs the furnace about 5 minutes at a time, maybe 2-3 times an hour, so if that furnace is 2.8 amps (just going by what someone above said), thats between 0.5 and 0.7 amp*hour per hour. If I heat for 10 hours thats 5-7 amp*hours. for 20 hours, thats 10-15 amp*hours a day.... with my dual flooded golf cart batteries I have approximately 110 AH of available power before the batteries are at 50%.

so I don't get what the problem is here.

Remember, we don't have problems, only challenges and opportunities!

My wife seems to manage to get the furnace to run much more than five minutes an hour in the shoulder seasons near the ocean here in the temperate northwest.

Other than that, the OP has a Casita and is planning on travelling across country. So, there's always the possibilities of colder weather, different trailer insulation, only having a single battery with less capacity, a CPAP added to the load, maybe a heavier hand on the thermostat - added up, it sounds like a potential challenge.

[John in Santa Cruz]

Originally Posted by Civilguy

Remember, we don't have problems, only challenges and opportunities!

My wife seems to manage to get the furnace to run much more than five minutes an hour in the shoulder seasons near the ocean here in the in the temperate northwest.

Other than that, the OP has a Casita and is planning on travelling across country. So, there's always the possibilities of colder weather, different trailer insulation, only having a single battery with less capacity, a CPAP added to the load - added up, it sounds like a potential challenge.

well, mine runs 5 minutes 2-3 times/hour....

but yeah, the casita is not well insulated at all, so needed quite a bit more heat to stay warm in freezing weather. one of several reasons we have the Escape now.

[Perryb67]

Originally Posted by John in Santa Cruz

when its ~40F out and I have my furnace set for 65F inside, my E21 classic w/ the extra insulation package only runs the furnace about 5 minutes at a time, maybe 2-3 times an hour, so if that furnace is 2.8 amps (just going by what someone above said), thats between 0.5 and 0.7 amp*hour per hour. If I heat for 10 hours thats 5-7 amp*hours. for 20 hours, thats 10-15 amp*hours a day.... with my dual flooded golf cart batteries I have approximately 110 AH of available power before the batteries are at 50%.

so I don't get what the problem is here.

How about everyone is different.

For us, we camp below 30F and our 5.0 is short 20-30 ah's at night, with our thermostat set at 58F. We always keep a vent cracked otherwise Terry can get a headache. It's amazing what we've realized once we purchased a Victron 712 battery monitor. At night we're running our fire/CO/LP monitors too, as well as the fridge, and charging a phone or two.

Enjoy,

Perry

[Ervin in Portland]

A few questions, how many watts is your panel, and how many amp hours in the battery?
I agree fully with Glenn, ditch the toaster oven and make coffee with a percolator or French press.

Wife uses a c-pap without humidifier, we have a group 31 with approx 55 amp hours to use. Occasional charging of phones, running led’s, no heater and never gets below 85%. Use a voltmeter which allows me to read both the state of the battery and the input I am getting from the solar panel.

Have a 50 watt Grape solar panel bought from Home Depot for 50 bucks and brings the battery to full charge in a couple of hours.

[gordon2]

Originally Posted by Ervin in Portland

...Use a voltmeter which allows me to read both the state of the battery and the input I am getting from the solar panel.
....

A general comment as you know this already..

If one measures the battery voltage when it has recently been charging, then the reading will be higher than the true state of charge measurement (surface charge). If you measure the battery voltage when there is a load, the reading will be below true state of charge measurement (voltage drop). The only way to get a voltage reading that accurately shows the state of charge is to make sure there is no charging or discharging for the prior few hours or more. But we tend to use or charge the battery most of the time. That is why I prefer a shunt and recording amp meter. It gives you a state of charge while the battery is in use, much like the gas gauge in your tow vehicle gives you a reading when traveling.. imagine if you had to park the car for a few hours before the gas gauge would give an accurate reading!

[Defenestrator]

Originally Posted by RockyBob

I wouldn't depend on tow vehicle (TV) charging the trailer battery effectively. There's been considerable discussion about this. The problem is the TV alternator output is driven by the needs of the TV battery, and since the TV battery is likely always near full charge the alternator voltage will be low, maybe 13.6 volts. With typical voltage drop between the TV battery and the trailer battery (0.5 to 1 volt?) the voltage at the trailer battery will not result in any charging. There are 12 volt-to-12 volt chargers available just for this problem. They take low voltage (around 12 volts) and step it up to the 14 or so volts that a depleted trailer battery would need to recharge. Available on line.

A 12V-12V charger and dedicated power line helps, but in practice it's not quite as dire as all that. The voltage drop will vary with current, and newer alternators actually can hit surprisingly high voltages in the bulk-charge stage. You also don't necessarily need 14V, just something above the current state of charge. Even when the TV battery is full, power will flow across to the lower-voltage trailer battery. In practice, I'd expect 3-10A of charge from the tow vehicle depending on the details.


As far as fan power goes, that'll depend drastically on duty cycle, which depends on weather and insulation. On a mild night it could very well only need to run 5-20% of the time and barely put a dent in the battery. Getting into the 0-10F range, even in a fully-insulated Escape, might mean more like a 90% duty cycle overnight and a big chunk taken out of battery charge.

[mariaandskip]

I'm still in the process of designing our system so any input is appreciated.

When we were living on our boat we had an engine battery and 2 house batteries. I replaced the factory alternator with a high out put alternator without the built in regulator. Then I installed a standard regulator to charge the engine battery and a 3 step regulator to charge the house batteries. I used real heavy (no 2 I think) wire for charging the house batteries. There were times that we went a week without running the engine to charge the batteries.
I was thinking of replacing the house battery with a lithium and putting an additional lithium "house" battery in the van. This way it gets charged when we are driving without the trailer behind us.

I'd appreciate any thoughts/feedback on this

[John in Santa Cruz]

I wouldn't want to have to be swapping batteries daily or whatever.

[mariaandskip]

Hi John
I wouldn't be swapping batteries daily just plugging into the vans pin connector. That would then be connecting the van house battery with the trailer house battery.




Indecision is the key to flexibility

[John in Santa Cruz]

my van shut off the trailer power when the van was off.