How long will my batterys last when I am not using generator

Hi,

Victron makes a better monitor for a lower price than the fabled trimetric. I have neither.

wintersun wrote:
A good addition that is not expensive or difficult to install is a Trimetric charge monitor. It will provide accurate information on the rate of discharge, amount of charge, and rate of charge with your current setup. Much more accurate than what the RV manufacturers install.

You can easily test for yourself as I have done. Fully charge the batteries and take a voltage reading. It should be 12.6 volts and definitely no less than 12.5v. Next run everything you can turn on and do so for 24 hours and then for another 24 hours and at the end of each interval do a voltage measurement.

If the batteries are healthy the voltage at 50% discharge should be 12.2 volts. At 75% discharge the voltage will be 12.0 volts. The deeper the discharge the longer it will take the batteries to get back to a full charge.

A 50% discharge is the maximum recommended for AGM type batteries. For flooded lead acid type (FLAT) the maximum recommended is 80%. Flooded also do much better with being discharged, partially recharged, and then discharged again compared to AGM and gel type batteries. This is why people tend to get very long life using "golf cart" FLAT batteries in their RV's.

A good addition that is not expensive or difficult to install is a Trimetric charge monitor. It will provide accurate information on the rate of discharge, amount of charge, and rate of charge with your current setup. Much more accurate than what the RV manufacturers install.

Dakzuki wrote:
I thought we were the only crazy people. We are notorious for not running heat while dry camping in cool (like snow overnight at Yellowstone) temps.

Glad to meet you! Glad to hear it snows in Yellowstone - we were there in the summer once and nearly cooked. It seemed incredibly hot to us, used to the cool of 1000 miles further north. I understood why air conditioniers and generators to power them are a necessity.

I always wake up in the morning with enough power to run my coffeemaker and the hairdryer off the inverter, but I cring when the panel shows a 100 amp discharge!!!

I'm not a big coffee person so I can't see the whole picture, but from an energy point of view it seems strange to burn fuel to create heat, convert to electricity at 30% efficiency in a generator, store it in heavy batteries with more losses and then convert it back to heat to make coffee. Why not eliminate all the inefficiencies and make coffee on the propane stove?

Last summer we were camping at a remote lake where you could clearly hear the loons calling. This is near the start of the Alaska highway where there is little need for air conditioning. It was wonderfully quiet - except for the guy running a generator all day to keep the coffee hot.

Using a volt meter check the voltage at your batteries. Should be 12.6+ volts at 100% with healthy battery. 12.06v at 50% charge level and 11.9 at 40% level. Generally speaking the batteries will last the longest if they are not discharged by more than 50% (flooded lead acid type can be discharged more than a AGM or gel type).

Easy enough to see what it takes to take the batteries down to where they show 12.1 volts and use that as your base. You can also see how long it takes with AC to recharge them to the maxium voltage they are able to provide.

On an ongoing basis installing a Trimetric or similar charge meter will make it easy to monitor what is going on throughout the day or a trip. Well worth the cost of buying and installing one.

Best book by far for general RV questions like this is the book ($11.32) "The Complete Book of Boondock RVing: Camping Off the Beaten Path" by Bill Moeller. Easy to read and extremely informative and directly applicable to RV users.

duckiee wrote:
Newbie here.
I know this might be a stupid question, but. How long can I use the house battery for electricity without them dying? I don't really want to test that out and have my batteries dead. I lack the understanding of how my battery electrical system works. How long I have until the house battery dies? How long I have for the chassis battery? How do they recharge? I am totally confused.

The only reason it might be a stupid question is that you have not told us the size and condition of your house batteries. So there is not way we can answer it, except to offer advise of where to look for battery education information.

As to the chassis battery, it may or may not charge while on shore power. Depends on how the manufacturer wired your charging system. Many chassis batteries only get charged by the engine's alternator. Many solve this by installing a Trik-L-Start unit.

Also you have a older coach!! That means that you also have a older converter/charger that is quite possiblity a single stage charger. There are notorious for killing batteries. Many replace their older converters with the newer style converters with 3 and 4 stage battery chargers, which are much better for maintaining your batteries while plugged into shore power. Mine is plugged in all the time for that very reason! My older coach has a newer Progressive Dynamics 9200 converter with the charge wizard. It does not over charge my batteries.

Our RV is an energy hog with many "phantom" draws. We have solar and when they tested before the install, almost one battery was used per day for those hidden items. I turn off all those pesky little ready lights on TVs/dvr/microwave(which I can't use on battery anyway but it lights up when on inverter!) anything that I can unplug or use a power strip on to turn off, I do so. We have replaced some lights with LED and that help tremendously, they use less that 10% of the other lights.

In general, most people I know can go 1-2 nights only without recharging some way. The less you use, the longer the battery will last- a given.

Older TVs using the inverter will chew through lots of stored power. Newer , smaller TVs use very little, new huge ones will use more. Furnace fans will kill the battery in one night. Even on propane, the fridge needs to draw power for igniting the propane.

It is a matter of figuring out what is essential, maybe using some battery lights and making whatever you have last as long as you can. as stated, beware of discharging the battery too low. Another thing is that last 10% recharge with out system is a trickle charge and can take what seems like forever to get to 100%.

Good luck with the battery side of life. Lots of good info given here.

we are power pigs I think.
Our knight has 4 interstate U2200 6 v batteries.
Boondocking, we run the genny for 2 hours in the morning, and 2 more before bed.

I always wake up in the morning with enough power to run my coffeemaker and the hairdryer off the inverter, but I cring when the panel shows a 100 amp discharge!!!

Harvey51 wrote:
You'll have to check it out for yourselves because different people use vastly different amounts of electricity. We have a small motorhome with no TV and the microwave is a breadbox, so no use for an inverter. LED lights halved our summer power usage. We don't seem to need a generator, either. We take a little drive every two or three days and the batteries recharge. No generator means no noise or exhaust smell and happy neighbours even in tents. We often camp at temps below freezing, always with a window or vent open because we like it cool at night, using the furnace only in the morning and evening. Of course, we use blankets and cuddle.

It may well come down to a lifestyle choice. Camp as if you were home and run the generator to keep all the conveniences running. Or give up TV and enjoy the quiet outdoors when camping.

I thought we were the only crazy people. We are notorious for not running heat while dry camping in cool (like snow overnight at Yellowstone) temps.

duckiee wrote:
Newbie here.
I know this might be a stupid question, but. How long can I use the house battery for electricity without them dying? I don't really want to test that out and have my batteries dead. I lack the understanding of how my battery electrical system works. How long I have until the house battery dies? How long I have for the chassis battery? How do they recharge? I am totally confused.

I know this isn't an answer, it's just what we get out of ours:

One size 29 deep cycle usually hangs in around 30-36 hours in our 34 foot fifth wheel.
A size 27 normally gives up at around 20-24 hours.
This is just using the on-board items.
We have no add-ons, just the water pump, lighting, fridge, DSI water warmer...etc
We have been lighting the trailer after dark with LED table lamps they last for days.

*The main group 29 battery we are on is 7 months old.
The group 27 is 4 months old.

You'll have to check it out for yourselves because different people use vastly different amounts of electricity. We have a small motorhome with no TV and the microwave is a breadbox, so no use for an inverter. LED lights halved our summer power usage. We don't seem to need a generator, either. We take a little drive every two or three days and the batteries recharge. No generator means no noise or exhaust smell and happy neighbours even in tents. We often camp at temps below freezing, always with a window or vent open because we like it cool at night, using the furnace only in the morning and evening. Of course, we use blankets and cuddle.

It may well come down to a lifestyle choice. Camp as if you were home and run the generator to keep all the conveniences running. Or give up TV and enjoy the quiet outdoors when camping.